BEIJING, May 8, 2009 (Reuters) — An invasion of unidentified worms has forced 50 herdsmen and their families from their grassland homes, taking 20,000 head of livestock with them, in northwest China's Xinjiang region, state news agency Xinhua said Friday.
The worms are packed up to 3,000 per square meter and chew through the grasslands like lawnmowers, leaving only brown soil in their wake, Xinhua said.
The agency described it as the worst plague in three decades in Usu, about 280 km (175 miles) west of the Xinjiang capital Urumqi.
Local experts could not identify the 2-cm (1 inch) long, thorny green worm with black stripes and samples had been sent to Xinjiang Agricultural University, Xinhua said.
"The pasture was green a week ago. But now the worms are creeping around, and they even come into my house. I have to sweep them out several times an hour," Xinhua quoted one herdsman as saying.
Xinjiang has in the past used chickens, ducks and other birds to fight locusts, which are also a menace on the grasslands, but so far they have shown little interest in the pesky worms.
One local official said the worms might be moth larvae that have flourished in the relatively warm winter and plenty of rain.
Pollination Crisis 'A Myth': Honeybees Are On The Rise, But Demand Grows Faster
The notion that a decline in pollinators may threaten the human food supply -- producing a situation that has been referred to as a "pollination crisis" -- can be considered a myth, at least where honey bees are concerned. (Credit: iStockphoto/Alexandru Magurean)
ScienceDaily (May 8, 2009) — The notion that a decline in pollinators may threaten the human food supply – producing a situation that has been referred to as a "pollination crisis" – can be considered a myth, at least where honey bees are concerned, say researchers reporting online on May 7th in Current Biology.
First of all, most agricultural crop production does not depend on pollinators. On top of that, while honey bees may be dwindling in some parts of the world, the number of domesticated bees world-wide is actually on the rise, their new report shows.
"The honey bee decline observed in the USA and in other European countries including Great Britain, which has been attributed in part to parasitic mites and more recently to colony collapse disorder, could be misguiding us to think that this is a global phenomenon," said Marcelo Aizen of Universidad Nacional del Comahue in Argentina. "We found here that is not the case."
By analyzing data from the Food and Agriculture Organization of the United Nations for temporal trends in the number of commercial bee hives, they found that the global stock of domesticated honey bees has increased by about 45 percent over the last five decades. That increase has primarily been driven by an increased demand for honey from a growing human population, rather than an increased need for pollinators, he added.
But the news isn't all good: The data also show that the demand for crops that rely on insects for pollination has more than tripled over the last half century, suggesting that the global capacity for pollination may still be under considerable stress. These crops include "luxury" agriculture items, now common in any supermarket, like plums, raspberries, and cherries, as well as mangos, guavas, Brazil nuts, and cashew nuts.
"We were particularly astonished when we found that the fraction of agricultural production that depends on pollinators, which includes all of these luxury agriculture items, started growing at a faster pace since the fall of communism in the former USSR and Eastern Europe, and at a much higher rate than the larger fraction of agricultural production that does not depend on pollinators, including wheat and rice, which just follow human population growth," Aizen said. "Although the primary cause of the accelerating increase of pollinator-dependent crops seems to be economic and political – not biological – their rapid expansion has the potential to trigger future pollination problems for both these crops and native species in neighboring areas."
The associated increase in demand for agricultural land could also hasten the destruction of habitat that now supports hundreds or thousands of species of wild pollinators, which would in turn cause a drop in crop yield, he said.
"Most importantly, decreasing yield by these pollinator-dependent crops surely would imply rising market prices, which undoubtedly would constitute a further incentive for their cultivation," Aizen said. "This situation would create a positive feedback circuit that could promote more habitat destruction and further deterioration of pollination services. The good news is that less-intensively managed agro-ecosystems that preserve patches of natural and semi-natural habitats and uncultivated field edges can sustain abundant and diverse communities of wild pollinators."
The researchers include Marcelo A. Aizen, Universidad Nacional del Comahue, Rio Negro, Argentina; and Lawrence D. Harder, of University of Calgary, Calgary, Alberta, Canada.
1. Marcelo A. Aizen and Lawrence D. Harder. The Global Stock of Domesticated Honey Bees Is Growing Slower Than Agricultural Demand for Pollination. Current Biology, 2009; DOI: 10.1016/j.cub.2009.03.071
ScienceDaily (Apr. 25, 2009) — Current estimates state that transport is responsible for about 25% of the energy-related greenhouse gas emissions worldwide. While biofuels are seen as a possible means to reduce these emissions, they are under heavy discussion in terms of economic cost benefits and their environmental and social impacts.
The EU promotes the production of biofuels and has set a target of 5.75% share of biofuels in the transport section for all EU Member States by 2010, and a target of 10% to be reached by 2020. Currently, the biofuel crops consist mainly of commonly known arable crops, such as cereals, maize or rape seed. Increasing the share of these crops could lead to the expansion of cultivated areas, and in turn, to an increasing pressure on the environment, habitat loss and biodiversity decrease, especially if forest, grassland, peatland and wetlands are converted into monoculture plantations for biofuels crops.
The so-called second generation biofuel crops, produced from nonfood, ligno-cellulosic materials such as wood, energy grass or any other cellulosic biomass, which are being developed, offer an alternative. The effects of their production on biodiversity are estimated to be less drastic than that of regular arable crops.
A recent paper by Eggers et al. presents a new method of assessing biodiversity impacts resulting from changing land use due to the production of biofuel crops in Europe, distinguishing between arable (first generation) and woody (second-generation) crop types. In particular, Eggers et al. focus on two questions: (1) what might happen if we doubled the current EU biofuel target of 5.75%, and (2) what might happen if we abolished the current biofuel target. While biodiversity as such includes all forms of life, their impact assessment was restricted to a set of 313 species pertaining to four taxonomical groups.
The results indicate that more species might suffer from habitat losses rather than benefit from a doubled biofuel target, while abolishing the biofuel target would mainly have positive effects. However, the possible impacts vary spatially and depend on the choice of biofuel crop, with woody crops being less detrimental than arable crops. The results give an indication for policy and decision makers of what might happen to biodiversity under a changed biofuel policy in the European Union. The presented approach is considered to be innovative as to date no comparable policy impact assessment has been applied to such a large set of key species at the European scale.
1. Jeannette Eggers, Katja Tröltzsch, Alessandra Falcucci, Luigi Maiorano, Peter H. Verburg, Erik Framstad, Gerald Louette, Dirk Maes, Szabolcs Nagy, Wim Ozinga and Ben Delbaere. Is biofuel policy harming biodiversity in Europe? GCB Bioenergy, 1, 2009, pp. 18-34 DOI: 10.1111/j.1757-1707.2009.01002.x
Insight Into Fish Disease To Help Protect Farmed Fish Stocks
ScienceDaily (Apr. 24, 2009) — Researchers funded by the Biotechnology and Biological Sciences Research Council (BBSRC) have gained a key insight into a disease that is devastating the UK's fish farming industry. The researchers have discovered that fish can harbour and spread proliferative kidney disease (PKD), a cause of major stock losses on fish farms, as well as being affected by the infection.
The discovery now paves the way for research to develop effective ways to combat the disease. The research was conducted by Professor Sandra Adams and Dr David Morris at the University of Stirling's Institute of Aquaculture and is reported in the latest edition of BBSRC Business magazine.
PKD is a debilitating condition for affected fish, leading to severe inflammation of the kidneys. PKD can cause major losses of newly introduced fish on infected farms - the estimated annual cost to the UK trout industry alone is £2.5M. Despite the impact of the disease and the importance of aquaculture to the UK food chain details about how PKD spread have been scarce.
Researchers had previously discovered the parasite in freshwater bryozoa, which are colony-forming animals that feed on microscopic algae. Some species of the bryozoa resemble plants and can fragment to form new colonies that could spread the disease.
Prof Adams and Dr Morris have now shown for the first time that native fish can also spread PKD, rather than being simply dead-end hosts.
Prof Adams said: "We were able to show that the parasite that causes deadly PKD in fish could cycle between brown trout and bryozoa indefinitely".
The researchers have also developed a working model in the lab for studying the lifecycle of the parasite, which will be critical for developing new control measures against the disease.
Their early results suggest that although brown trout are hosts of PKD they are not very susceptible to the disease, whereas farmed rainbow trout in the UK have a severe immune response to PKD that can kill the fish.
But, as Prof Adams explains: "In their native environment in the USA, rainbow trout are more resilient to PKD. This suggests that there are at least two strains of this particular parasite: one adapted to North American species and one adapted to European species. Therefore, rainbow trout introduced to European waters are likely to be infected with the wrong strain of the parasite, which explains the severe immune response and subsequent disease".
There have been recent reports of PKD affecting wild salmon in Europe and North America, indicating that it is an emerging threat to these ecologically and economically important fisheries.
Prof Janet Allen, Director of Research at BBSRC, said: "Farmed fish are a crucial part of the food chain, providing nutritious and affordable food for many people. They are also economically important in many areas. When a disease such as this threatens fish farming it is vital that we provide the science to understand the problem and its source and deliver the research to tackle it."
Owls, Kestrels In Middle East: Flying Mouse-traps Control Pests Without Chemicals
Barn Owls have been used as agricultural pest controllers around the world. (Credit: Amir Ezer)
ScienceDaily (Apr. 24, 2009) — Barn owls (Tyto alba) and common kestrels (Falco tinnunculus) are being encouraged by farmers in Israel, Jordan and the Palestinian Authority to control agricultural pests instead of using harmful chemicals. “The two species provide round-the-clock predation of mice, rats and voles and have been used throughout history as natural pest controllers”, said Dr Yossi Leshem - Society for the Protection of Nature in Israel (SPNI; BirdLife in Israel). “A pair of Barn Owls alone can eat over 2,000 rodents in a year!”
“Israel is very important for birds of prey - raptors living here year-round are joined by migrants which soar through on thermals in the spring, and birds which stay the winter”, noted Yossi. Sadly, in 1997 large numbers of raptors were accidentally poisoned in Israel’s Bet-She’an and Hulas Valleys after eating prey which contained harmful levels of pesticides.
“We needed an alternative to using chemicals, and knew that Barn Owls and Common Kestrels - two of the most abundant raptors living in Israel - have been used as agricultural pest controllers around the world”. However, modern development has reduced the number of suitable nest sites available in barns, attics and deserted buildings. “This was easily remedied by proving next boxes which were eagerly inhabited by the birds”, said Dr Leshem.
The first boxes were erected for Barn Owls in the fields of an environmentally-friendly Kibbutz Sde Eliyahu (communal farm) in the Bet-She’an Valley. Boxes have now been peppered throughout the valley, and 70% are already occupied by owls. “We estimate that Barn Owls are removing at least 80,000 rodents from Bet-She’an’s fields each year”, said Shauli Aviel – farmer at Kibbutz Sde Eliyahu. “This has ensured a reduction in the damage pesticides cause to people, soil, water, wildlife and migrating birds”.
The successful project was soon expanded to also include Common Kestrels, with nesting boxes erected throughout Israel. “Kestrels hunt during the day and Barn Owls at night”, said Motti Charter a researcher at Tel-Aviv University. “This constant 24-hour threat of predation has caused changes in the pest’s behaviour and resulting in less crop damage”.
During 2005-2008 the project was expanded beyond the borders of Israel, and 37 nesting boxes were erected in Jordanian fields to the east of the Jordan River. In the Muslim tradition, Barn Owls symbolize bad luck and many of the Jordanian farmers were hesitant to cooperate at first. “Once a few Jordanian farmers used Barn Owls instead of chemical pesticides with tremendous success, others were quick to follow suit and were proud of the Barn Owls attracted to their fields by the nesting boxes”, said Dr Leshem.
In parallel, Imad Atrash, Director of the Palestine Wildlife Society (PWLS; BirdLife in Palestine), erected 10 nesting boxes for Barn Owls in the fields of Jericho in the Palestinian Authority.
The success of using birds of prey to control rodents now continues to go from strength to strength. In Israel the General Directors of the Ministry of Agriculture and the Ministry of Environmental Protection decided to promote a three-year national project (2008-2010) using Barn Owls and Common Kestrels countrywide, together with the Baracha Foundation, the SPNI (BirdLife in Israel) and Tel-Aviv University.
Furthermore, USAID-MERC (Middle East Regional Cooperation) recently provided funds for a research project to compare experimental results of using Barn Owls and Kestrels in Israel, Jordan and the Palestinian Authority.
“At present we have 1,480 nesting boxes located throughout Israel, with approximately 600 pairs of nesting Barn Owls”, said Dan Alon - Director of the Israel Ornithological Center and SPNI. SPNI are now seeking to develop the project further and create a regional project with the Palestinians and Jordanians. “We hope in the future to extend the project even further afield to African countries, thus developing a cross-continental environmental concept that will drastically diminish the harm to local and migrating birds”, concluded Dan Alon.
Conserving many species, especially migratory birds, requires international action to work across physical and political borders. Soaring migratory birds, including large-bodied birds of prey, glide between areas of rising hot air to aid their long-distance flights. However, soaring cannot be used over large water bodies or high mountains and concentrates birds into narrow geographic corridors. Making soaring migratory highly vulnerable to localised threats - such as pesticide use - in countries like as Israel, Jordan and the Palestinian Authority.
In response, BirdLife has launched a new ‘Migratory Soaring Birds’ project to tackle wider threats to soaring birds in the Middle East and Africa.
Agricultural Contaminants Threaten Doñana National Park In Spain
Puebla del Río ricefield, in Isla Mayor del Guadalquivir. (Credit: Juan López Barea / SINC)
ScienceDaily (Apr. 27, 2009) — Eleven years after the Aznalcóllar pyrite mine rupture, in the north of the Doñana National Park (Huelva), the contamination caused from the spill seems to have been overcome. Spanish researchers have, however, evaluated the environmental quality of the Park's environment with crayfish as bio-indicators.
This methodology demonstrates that contaminants from intensive agriculture being carried out close to the Park are the main threat in this Biosphere Reserve and are already affecting the Puebla del Río and Matochal rice paddies.
The six million cubic metre acid water and toxic pyrite mud spill in 1998 did not have dramatic effects on the Doñana National Park because it did not enter the park limits. There is, however, still concern in the area due to agricultural activity and the use of pesticides in harvests close to the protected Natural Space which could threaten the Park's environmental quality.
"This type of contamination is more diffuse, difficult to evaluate and less relevant in the media than a mine spill", explains Juan López-Barea to SINC, the study's main author and head of the Department of Biochemistry and Molecular Biology at the University of Cordoba (UCO). And yet, agro-chemical contaminants affect, above all, areas situated between the Guadiamar Stream and the Guadalquivir River, sites of important rice cultivation.
The study, which has been published in Science of the Total Environment, has determined that the upper courses of the Rocina Stream, and especially the Partido Stream, are the most affected by agricultural contaminants, since the most intense fruit cultivation is in these areas. The researchers reached these conclusions upon combining the responses from the conventional biomarkers in crayfish (Procambarus clarkii), used as bio-indicators, with the massive analysis of changes in protein expression.
Crayfish: excellent contamination bio-indicators
In the spring and autumn of 2003 and 2004, scientists evaluated the level of contamination at six sites close to the Park, using two sites inside the Doñana Biological Station (EBD-CSIC) with almost no contaminants as a reference. During the four campaigns, and knowing that crayfish respond effectively to pesticides, organic contaminants and pro-oxidative chemical elements, the experts captured and dissected close to 600 animals.
Crayfish, which tend to live in the studied areas, showed an increase in pesticides and pro-oxidative organic contaminants in the Park and its environment, with changes in 12 conventional biochemical biomarkers and changes in the expression of 35 proteins.
This proteomic approach, based on the application of modern methodologies from the Biology of Systems (Proteomics, Transcriptomics, Metallomics), has made it possible to clarify that there are two "highly contaminated" sites: the Puebla del Río (on the Isla Mayor of the Guadalquivir, between the river and the Doñana National Park) and the Matochal (in the Doñana natural ecosystem marsh) rich paddies.
In the Matochal, rice is extensively cultivated "in which pesticides, algaecides and fungicides are used intensively, which alters the expression of a maximum number of proteins", point out the researchers.
The methods employed in this study, developed in Córdoba, are the most groundbreaking of their kind in the world. López-Barea leads the research group BIO151 of Environmental Proteomics at the UCO and applies cutting-edge methodologies to evaluate land and aquatic ecosystems.
1. Vioque-Fernández, Amalia et al. Assessment of Doñana National Park contamination in Procambarus clarkii: Integration of conventional biomarkers and proteomic approaches. Science of The Total Environment, 2009; 407 (5): 1784 DOI: 10.1016/j.scitotenv.2008.11.051
* Sam Jones and agencies * guardian.co.uk, Thursday 21 May 2009 22.14 BST
After three years of intrigue and confusion, not to mention a death toll of 400, the great Penghu archipelago goat mystery may finally have been solved.
Officials investigating the unexplained deaths of scores of the animals on the windy island chain in the Taiwan strait believe that the introduction of noisy wind turbines could have given the unfortunate goats a fatal case of exhaustion.
After the eight turbines were installed on the archipelago, a farmer told the authorities that his livestock were beginning to die for no apparent reason, according to Council of Agriculture inspection official Lu Ming-tseng.
It now appears that the turbines' high-volume, late-night, spinning was more than just an aural nuisance and could have induced terminal insomnia in the animals.
Lu pointed out that there was no reason why goats should react differently to humans when it came to the turbines' attendant noise pollution.
"If noise at night can keep people awake, then it could also keep the goats awake, and when the wind kicks up it makes a louder noise," he said.
He said that the agricultural authorities would do more tests to rule out any other causes of death, adding that if the giant power-generating turbines proved to be at fault, Taipower might help the farmer with moving costs. But a spokesman for Taipower said the firm doubted the goats had died from the noise.
Close up of the beehive fence which can withstand crop raids by elephants. (Credit: Copyright Oxford University/Lucy King)
ScienceDaily (June 6, 2009) — A fence made out of beehives wired together has been shown to significantly reduce crop raids by elephants, Oxford University scientists report.
The fence is constructed of log beehives suspended on poles beneath tiny thatched roofs (to keep off the sun). The hives are connected by eight metre lengths of fencing wire. Elephants avoid the hives and will attempt to push through the wire but this causes the hives to swing violently causing the elephants to fear an attack of angry bees.
The results of a pilot study in Kenya, published in the African Journal of Ecology, show that a farm protected by the beehive fence had 86 per cent fewer successful crop raids by elephants and 150 per cent fewer raiding elephants than a control farm without the fence.
The reduction occurred despite the fact that none of the hives were occupied at the time suggesting that elephants remember painful past encounters with African honeybees and avoid the sights and smells associated with them.
‘Our previous research has shown that elephants are scared away by recordings of the buzzing of angry bees,’ said Lucy King of Oxford University’s Department of Zoology who led the project in collaboration with the charity Save the Elephants. ‘We designed the beehive fence as an affordable and practical way of applying this knowledge to create a barrier that the elephants would be afraid to cross.’
‘The reaction from the farmers involved in our pilot study has been very positive,’ said Lucy King. ‘Our beehive fence design has been shown to be robust enough to survive elephant raids and cheap enough for farmers to construct themselves – especially as it also gives protection against cattle rustlers and, when occupied by colonies of African honeybees, will give the farmers two or three honey harvests a year that they can sell to offset the cost of building the fence.’
During the six-week pilot study the team used GPS to track one particularly notorious elephant raider dubbed ‘Genghis Khan’. Genghis was spotted raiding by several farmers and was observed amongst a herd of eighteen bull elephants returning from crop raids and his GPS movements were shown to closely match the routes of the raiding groups.
Despite their thick hides adult elephants can be stung around their eyes or up their trunks, whilst calves could potentially be killed by a swarm of stinging bees as they have yet to develop this thick protective skin.
Lucy King said: ‘We hope that these results will encourage farmers in other areas losing crops to elephant raiders to build their own beehive fences and help to reduce the conflict between humans and elephants that can lead to the tragedy of animals being shot, as well as farmers suffering devastating losses to the crops that are their livelihood.’
New Category Of Fat In Mammalian Cells May Help Explain How Toxin Harms Farm Animals
ARS scientists and their colleagues have discovered a new category of fats in mammalian cells whose chemical backbone is based on the amino acid alanine rather than serine. (Credit: ARS)
ScienceDaily (June 9, 2009) — A new category of fats in mammalian cells discovered by Agricultural Research Service (ARS) scientists and colleagues may help explain how a harmful toxin called fumonisin causes disease in farm animals.
The discovery could open up a new research area for exploring ways to reduce the toxic effects of fumonisin, which is found in corn that has been infected with a fungus called Fusarium. Fumonisin is known to cause a host of diseases, such as equine leukoencephalomalacia, which is a brain disease in horses, and porcine pulmonary edema, a lung disease in swine.
In previous work, these scientists found that fumonisin inhibits the formation of a group of fats known as sphingolipids and disrupts the metabolism of sphingolipids and other fats. It is now known that this disruption of fat metabolism is the cause of the animal diseases and also kidney and liver toxicity and cancer in rodent animal models. In the earlier studies, this group showed that inhibition increases the levels of several well-known sphingolipid metabolites and an unidentified sphingolipid which was coined "the mystery peak."
ARS toxicologist Ronald Riley at the ARS Richard B. Russell Research Center in Athens, Ga., and colleagues at Health Canada in Ottawa, Emory University in Atlanta, Ga., and the Georgia Institute of Technology in Atlanta identified the "mystery" compound. The research was published recently in the Journal of Biological Chemistry.
Riley and his colleagues found that the first enzyme that makes the backbone--sphinganine--common to all sphingolipids normally uses serine as a substrate. However, the mystery compound was being produced because the enzyme was using the amino acid "alanine" instead.
This is important because the oxygen atom which is found on serine is critical in the formation of more complex sphingolipids. Thus, this new sphingoid base was called 1-deoxysphinganine and serves as the backbone for a new category of sphingolipids (1-deoxydihydroceramides) in mammalian cells and tissues.
This new sphingoid base accumulates in cells and tissues after fumonisin exposure. Riley and his colleagues showed that the amount of 1-deoxysphinganine rises when levels of serine fall relative to alanine. Thus, these compounds are an underappreciated category of bioactive sphingolipids that might play important roles in cell regulation and disease.
ScienceDaily (June 10, 2009) — No human is a clone of their parents but the same cannot be said for other living things. While your DNA is a combination of half your mother and half your father, other species do things differently. The advantage of clonal reproduction is that it produces an individual exactly like an existing one—which would be very useful for farmers who could replicate the best of their animals or crops without the lottery of sexual reproduction. Clonal reproduction of crop species took a step closer to being realised with new research published in PLoS Biology.
The type of cell division that creates eggs and sperm is called meiosis, and it differs from 'normal' cell division (mitosis) because instead of producing two genetically identical daughter cells, it produces four cells each containing only half of the parental amount of DNA. Meiosis occurs in all species that reproduce sexually, from microorganisms such as yeast to plants, animals and human beings. This new paper blurs the line between the two different types of cell division by showing a plant where three specific mutations are experimentally combined. These divisions are normally meiotic – which make pollen and egg cells – and are replaced by mitotic divisions.
The work, by a team of researchers in France and Austria, is potentially very important commercially, because it makes the creation of stable new mutant crops—such as plants of a different colour, or with a different yield, etc.—much simpler. It is now much closer to being possible to reproduce a plant that produces perfect potatoes, maize or rice, without the lottery of reassortment that each meiotic division and ensuing fertilization introduces.
The first steps of both meiosis and mitosis are the replication of the dividing cell's DNA. Once replication has occurred, the chromosomes condense into tightly bound structures, and in mitosis these form an X shape in which each half of the X is a chromatid, comprising one complete copy of the chromosome. The double-chromatid chromosomes line up along the centre of the cell. In mitosis, the two chromatids are pulled apart—the X is divided along one axis of symmetry—and these then pass into two genetically identical daughter cells. In meiosis, there are two lining up and dividing phases. The first lining up is of homologous chromosomes—all chromosomes in an adult cell have a partner, members of the partnership coming from the mother and father of the cell—and these homologous chromosomes are each made up of two chromatids. The first division divides homologous pairs of chromosomes while the second meiotic division is just like the mitotic di vision: the chromosomes line up at the middle of the new cell and the chromatids divide at the centre of the X.
Thus the differences between mitosis and meiosis are that meiosis has two rounds of division; co-segregation of sister chromatids at the first division; and recombination that occurs during the first division—a swapping over process that adds more genetic diversity to offspring. The new work, led by Raphael Mercier, identifies a gene that controls one of these three features—entry into the second meiotic division—in the sexual plant Arabidopsis thaliana. By combining a mutation in this gene with two other previously described mutations—one that eliminates recombination and another that modifies chromosome segregation—the authors have created a strain of plant (called MiMe for 'mitosis instead of meiosis') in which meiosis is totally replaced by mitosis.
MiMe plants produce pollen and eggs that are genetically identical to their parent. If MiMe eggs are self-fertilized by MiMe sperm, the offspring plant has twice as much DNA as the parent generation, and has all the genes from this single parent.
Thus the authors have made a form of asexual reproduction possible in a normally sexual species. Turning meiosis into mitosis is not enough to reach clonal reproduction, but it's a giant leap towards it. This has potential revolutionary applications in crop improvement and propagation.
This work was supported by an INRA postdoctoral fellowship to Id'E. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
1. d'Erfurth et al. Turning Meiosis into Mitosis. PLoS Biology, 2009; 7 (6): e1000124 DOI: 10.1371/journal.pbio.1000124
Milk Goes 'Green': Today's Dairy Farms Use Less Land, Feed And Water
Modern milk production system that has a smaller carbon footprint than mid-20th century farming practices, according to new research. (Credit: iStockphoto/Peter Clark)
ScienceDaily (June 11, 2009) — Dairy genetics, nutrition, herd management and improved animal welfare over the past 60 years have resulted in a modern milk production system that has a smaller carbon footprint than mid-20th century farming practices, says a Cornell University study in the Journal of Animal Science (June 2009).
"As U.S. and global populations continue to increase, it is critical to adopt management practices and technologies to produce sufficient high-quality food from a finite resource supply, while minimizing effects upon the environment," says Jude Capper, lead author and a recent Cornell post-doctoral researcher working with Dale E. Bauman, Cornell Liberty Hyde Bailey Professor of Animal Science.
The study shows that the carbon footprint for a gallon of milk produced in 2007 was only 37 percent of that produced in 1944. Improved efficiency has enabled the U.S. dairy industry to produce 186 billion pounds of milk from 9.2 million cows in 2007, compared to only 117 billion pounds of milk from 25.6 million cows in 1944. This has resulted in a 41 percent decrease in the total carbon footprint for U.S. milk production.
Efficiency also resulted in reductions in resource use and waste output. Modern dairy systems only use 10 percent of the land, 23 percent of the feedstuffs and 35 percent of the water required to produce the same amount of milk in 1944. Similarly, 2007 dairy farming produced only 24 percent of the manure and 43 percent of the methane output per gallon of milk compared to farming in 1944.
Joining Capper and Bauman on the paper is Roger A. Cady, Cornell '74, MS '77, PH.D. '80, a scientist at Elanco.
Research fund were provided to Bauman as a Liberty Hyde Bailey Professor and to the Cornell Agricultural Experiment Station. Capper has recently joined the faculty at Washington State University as assistant professor.
1. Capper, J. L., Cady, R. A., Bauman, D. E. The environmental impact of dairy production: 1944 compared with 2007. Journal of Animal Science, 2009; 87 (6): 2160 DOI: 10.2527/jas.2009-1781
ScienceDaily (June 15, 2009) — Potato blight, false mildew, sudden oak death and a disease in salmon are all caused by a group of miniscule, yet destructive, organisms called Oomycetes. Because of their changeability and huge numbers, they are able to overwhelm the defence mechanisms of both plants and animals.
The use of chemicals is usually the only remedy but this is also undesirable. Will future research offer a sustainable means of combating these blights and preventing failed harvests? Francine Govers, professor at Wageningen University, can see sporadic openings left by the pathogens and they provide a strategic starting point for combating the infections.
There are between 1000 and 2000 species in the group of micro-organisms, the Oomycetes (‘egg moulds’). They are not fungi. In fact, fungi (including toadstools) are more closely related to man than to these one-celled egg moulds. However, the effect of the latter on crops and animals is disastrous as was demonstrated by the potato blight that entered Europe via Belgium in 1845, advancing very rapidly, and causing the Great Irish Famine.
Prof. Francine Govers listed the limited number of strategies available for keeping the pathogen, Phytophthora infestans ('the destroyer of plants ') under control. The approach also provides an opportunity for reducing the quantity of pesticides used per hectare in the Netherlands, the highest levels of which happen to be in potatoes.
Combat takes place on a microscopic scale, the pathogen trying to work its way through the biological defences of the host, the potato plant. Phytophthora attacks the plant using a special group of proteins, the RXLR effectors. It has a huge and diverse arsenal available with some 560 RXLR effectors, so the odds of it finding a suitable weapon to break through the plant's defence mechanism is very high. If the attack succeeds, the effectors breach the plant's defences by suppressing its resistance. The spores of P. infestans can then make the most of the foodstuffs available and reproduce themselves, causing the death of the plant. Wild potato plants which grow in South America are reasonably resistant to such attacks because potato-resistant proteins recognize the invaders and block their advance.
Research efforts, including those at Wageningen, have meanwhile identified more than 10 resistant genes which make resistant proteins. Seven of those are known to contain the RXLR effector. If recognition is not 100% as, for example, when the RXLR effector looks slightly different, the invader escapes attack and can reproduce after all. This is how the pathogen, after a certain number of years, becomes able to break through the resistance in potatoes crossed with wild strains.
Phytopathologists are trying to understand the interaction better. The challenge is to predict whether a pathogen strain is going to infect a field where resistant potato cultivars are growing. By taking samples, a DNA chip can be used to determine which strains are present in the field and what sort of RXRL arsenal they have. It is then possible to establish which potato cultivars will not be affected by Phytophthora and which will. Only in the latter case is it necessary to spray. How long it will take to put this method into practice depends, according to Prof. Govers, on how quickly new combinations of resistant gene and RXLR effectors with all the variants can be identified.
Researchers are not putting all their money on one horse; they are also looking at the weak links in the life cycle of Phytophthora and at the genetic properties that are unique to the Oomycetes. Thus, it has been shown that a certain enzyme, phospholipase D, takes on novel forms in Oomycetes. Precisely these forms are ideal for applying control because the specific inhibition technique has no direct effect on other useful organisms, including the crop itself.
To finish, Prof. Govers pointed to a biological control technique. Soil bacteria belonging to the genus Pseudomonas attack spores of Phytophthora, making use of a small, special protein. It is not yet understood how this protein destroys the spores. By analysing 15,000 genes in Phytophthora, researchers have found candidates which may provide new and specific points of inquiry.
Massive Imbalances Found In Global Fertilizer Use, Resulting In Malnourishment In Some Areas And Serious Pollution Problems In Others
A scientific report of three corn-growing regions of the world finds massive imbalances in nitrogen fertilizer use, resulting in malnourishment in some areas and pollution problems in others. (Credit: Scott Bauer, Agricultural Research Service, USDA)
ScienceDaily (June 18, 2009) — Synthetic fertilizers have dramatically increased food production worldwide. But the unintended costs to the environment and human health have been substantial. Nitrogen runoff from farms has contaminated surface and groundwater and helped create massive "dead zones" in coastal areas, such as the Gulf of Mexico. And ammonia from fertilized cropland has become a major source of air pollution, while emissions of nitrous oxide form a potent greenhouse gas.
These and other negative environmental impacts have led some researchers and policymakers to call for reductions in the use of synthetic fertilizers. But in a report published in the June 19 issue of the journal Science, an international team of ecologists and agricultural experts warns against a "one-size-fits-all" approach to managing global food production.
"Most agricultural systems follow a trajectory from too little in the way of added nutrients to too much, and both extremes have substantial human and environmental costs," said lead author Peter Vitousek, a professor of biology at Stanford University and senior fellow at Stanford's Woods Institute for the Environment.
"Some parts of the world, including much of China, use far too much fertilizer," Vitousek said. "But in sub-Saharan Africa, where 250 million people remain chronically malnourished, nitrogen, phosphorus and other nutrient inputs are inadequate to maintain soil fertility." China and Kenya
In the Science report, Vitousek and colleagues compared fertilizer use in three corn-growing regions of the world--north China, western Kenya and the upper Midwestern United States.
In China, where fertilizer manufacturing is government subsidized, the average grain yield per acre grew 98 percent between 1977 and 2005, while nitrogen fertilizer use increased a dramatic 271 percent, according to government statistics. "Nutrient additions to many fields [in China] far exceed those in the United States and northern Europe--and much of the excess fertilizer is lost to the environment, degrading both air and water quality," the authors wrote.
Co-author F.S. Zhang of China Agriculture University and colleagues recently conducted a study in two intensive agricultural regions of north China in which fertilizer use is excessive. Their results showed that farmers in north China use about 525 pounds of nitrogen fertilizer per acre (588 kilograms per hectare) annually--releasing about 200 pounds of excess nitrogen per acre (227 kilograms per hectare) into the environment. Zhang and his co-workers also demonstrated that nitrogen fertilizer use could be cut in half without loss of yield or grain quality, in the process reducing nitrogen losses by more than 50 percent.
At the other extreme are the poorer countries of sub-Saharan Africa, such as Kenya and Malawi. In a 2004 study in west Kenya, co-author Pedro Sanchez and colleagues found that farmers used only about 6 pounds of nitrogen fertilizer per acre (7 kilograms per hectare)--little more than 1 percent of the total used by Chinese farmers. And unlike China, cultivated soil in Kenya suffered an annual net loss of 46 pounds of nitrogen per acre (52 kilograms per hectare) removed from the field by harvests.
"Africa is a totally different situation than China," said Sanchez, director of tropical agriculture at the Earth Institute at Columbia University. "Unlike most regions of the world, crop yields have not increased substantially in sub-Saharan Africa. Nitrogen inputs are inadequate to maintain soil fertility and to feed people. So it's not a matter of nutrient pollution but nutrient depletion."
U.S. and Europe
The contrast between Kenya and China is dramatic and will require vastly different solutions, the authors said. However, large-scale change is possible, they said, noting that since the 1980s, increasingly stringent national and European Union regulations and policies have reduced nitrogen surpluses substantially in northern Europe.
In the Midwestern United States, over-fertilization was the norm from the 1970s until the mid-1990s. During that period, tons of excess nitrogen and phosphorus entered the Mississippi River Basin and drained into the Gulf of Mexico, where the large influx of nutrients has triggered huge algal blooms. The decaying algae use up vast quantities of dissolved oxygen, producing a seasonal low-oxygen dead zone in the Gulf that in some years is bigger than the state of Connecticut.
Since 1995, the imbalance of nutrients--particularly phosphorus--has decreased in the Midwestern United States, in part because better farming techniques have increased yields. Statistics show that from 2003 to 2005, annual corn yields in parts of the Midwestern United States and north China were almost the same, even though Chinese farmers used six times more nitrogen fertilizer than their American counterparts and generated nearly 23 times the amount of excess nitrogen.
"U.S. farmers are managing fertilizer more efficiently now," said co-author Rosamond Naylor, director of Stanford's Program on Food Security and the Environment. However, environmental problems have not disappeared. "The dead zone in the Gulf of Mexico persists due to continued fertilizer runoff and animal waste from increased livestock production," said Naylor, a professor of environmental Earth system science and senior fellow at Stanford's Woods Institute and Freeman Spogli Institute for International Studies.
Low nitrogen in Africa
In sub-Saharan Africa, the initial challenge is to increase productivity and improve soil fertility, the authors said. To meet that challenge, co-author Sanchez recommends that impoverished farmers be given subsidies to purchase fertilizer and good-quality seeds. "In 2005, Malawi was facing a serious food shortage," he recalled. "Then the government began subsidizing fertilizer and corn seeds. In just four years production tripled, and Malawi actually became an exporter of corn."
Food production is paramount, added co-author G. Philip Robertson, a professor of crop and soil sciences at Michigan State University. "Avoiding the misery of hunger is and should be a global human priority," Robertson said. "But we should also find ways to do this without sacrificing other key aspects of human welfare, among them a clean environment. It doesn't have to be an either/or choice."
For countries where over-fertilization is a problem, the authors cited a number of techniques to reduce environmental damage. "Some of these--such as better-targeted timing and placement of nutrient inputs, modifications to livestock diets and the preservation or restoration of riparian vegetation strips--can be implemented now," they wrote.
Designing sustainable solutions also will require a lot more scientific data, they added. "Our lack of effective policies can be attributed, in part, to a lack of good on-farm data about what's happening with nutrient input and loss over time," said co-author Alan Townsend, an associate professor of ecology and evolutionary biology at the University of Colorado-Boulder. "Both China and the European Union have supported agricultural research that yields policy-relevant information on nutrient balances. But the U.S. is particularly lacking in long-term data for a country with such a well-developed scientific enterprise."
Even in Europe, with its strong research programs on nutrient balances and stringent policies for reducing fertilizer runoff, nitrogen pollution remains substantial. "The problem of mitigation of excess nitrogen loss to waters is not easily resolved," said co-author Penny Johnes, director of the Aquatic Environments Research Centre at the University of Reading, U.K. "Society may have to face some difficult decisions about modifying food production practices if real and ecologically significant reductions in nitrogen loss to waters are to be achieved."
According to Vitousek, it is important in the long run to avoid following the same path to excess in sub-Saharan Africa that occurred in the United States, Europe and China. "The past can't be altered, but the future can be and should be," he said. "Agricultural systems are not fated to move from deficit to excess. More effort will be required to develop intensive systems that maintain their yields, while minimizing their environmental footprints."
Other co-authors of the Science report are Tim Crews, Prescott College; Mark David, University of Illinois at Urbana-Champaign; Laurie Drinkwater, Cornell University; Elisabeth Holland, National Center for Atmospheric Research; John Katzenberger, Aspen Global Change Institute; Luiz Martinelli, University of São Paulo, Brazil; Pamela Matson, Stanford University; Generose Nziguheba, Columbia University; Dennis Ojima, The H. John Heinz III Center for Science, Economics and the Environment; and Cheryl Palm, Columbia University.
This work is based on discussions at the Aspen Global Change Institute supported by NASA, the William and Flora Hewlett Foundation, and the David and Lucile Packard Foundation; and at a meeting of the International Nitrogen Initiative sponsored by the Scientific Committee on Problems of the Environment.
1. P.M. Vitousek et al. Nutrient Imbalances in Agricultural Development. Science, June 19, 2009
Domestication Of Chile Pepper Provides Insights Into Crop Origin And Evolution
These are varieties of four domesticated chiles. (Credit: Dr. Seung-Chul Kim, Department of Botany and Plant Sciences, University of California, Riverside, California)
ScienceDaily (June 19, 2009) — Chile peppers have long played an important role in the diets of Mesoamerican people. Capsicum annuum is one of five domesticated species of chiles and is one of the primary components of these diets. However, little is known regarding the original location of domestication of C. annuum and the genetic diversity in wild relatives. Researchers have now found a large amount of diversity in individuals from the Yucatan Peninsula, making this a center of diversity for chiles.
Without the process of domestication, humans would still be hunters and gatherers, and modern civilization would look very different. Fortunately, for all of us who do not relish the thought of spending our days searching for nuts and berries, early civilizations successfully cultivated many species of animals and plants found in their surroundings. Current studies of the domestication of various species provide a fascinating glimpse into the past.
A recent article by Dr. Seung-Chul Kim and colleagues in the June 2009 issue of the American Journal of Botany explores the domestication of chiles. These hot peppers, found in everything from hot chocolate to salsa, have long played an important role in the diets of Mesoamerican people, possibly since as early as ~8000 B.C. Capsicum annuum is one of five domesticated species of chiles and is notable as one of the primary components, along with maize, of the diet of Mesoamerican peoples. However, little has been known regarding the original location of domestication of C. annuum, the number of times it was domesticated, and the genetic diversity present in wild relatives.
To answer these questions, Dr. Kim and his team examined DNA sequence variation and patterns at three nuclear loci in a broad selection of semiwild and domesticated individuals. Dr. Kim et al. found a large amount of diversity in individuals from the Yucatan Peninsula, making this a center of diversity for chiles and possibly a location of C. annuum domestication. Previously, the eastern part of central Mexico had been considered to be the primary center of domestication of C. annuum. On the basis of patterns in the sequence data, Dr. Kim et al. hypothesize that chiles were independently domesticated several times from geographically distant wild progenitors by different prehistoric cultures in Mexico, in contrast to maize and beans which appear to have been domesticated only once.
Geographical separation among cultivated populations was reflected in DNA sequence variation. This separation suggests that seed exchange among farmers from distant locations is not significantly influencing genetic diversity, in contrast to maize and beans seeds, which are traded by farmers across long distances. Less genetic diversification was seen in wild populations of C. annuum from distant locales, perhaps as a result of long-distance seed dispersal by birds and mammals.
Across the three loci studied, Dr. Kim and colleagues found an average reduction in diversity of 10% in domesticated individuals compared with the semiwild individuals. Domesticated chiles in traditional agricultural habits, however, harbor unique gene pools and serve as important reservoirs of genetic diversity important for conserving biodiversity.
This work was conducted primarily by Araceli Aguilar-Meléndez as her dissertation project under the guidance of Drs. Kim and Mikeal Roose in the Department of Botany and Plant Sciences at the University of California at Riverside. The research was supported by the University of California Institute for Mexico and the United States (UC MEXUS), El Coneso Nacional de Ciencia y Technología (CONACYT), and a gift from the McIlhenny Company. Aguilar-Meléndez, Kim, and their colleagues plan to continue research on this remarkably variable and economically important spice in Mesoamerica.
World’s First Self-Irrigating Desert Plant Discovered
* By Hadley Leggett * July 10, 2009 |
A desert plant has apparently figured out how to water itself.
Ecologists had been puzzling over the desert rhubarb for years: Instead of the tiny, spiky leaves found on most desert plants, this rare rhubarb boasts lush green leaves up to a meter wide. Now scientists from the University of Haifa-Oranim in Israel have discovered that ridges in the plant’s giant leaves actually collect water and channel it down to the plant’s root system, harvesting up to 16 times more water than any other plant in the region.
“It is the first example of a self-irrigating plant,” said plant biologist Gidi Ne’eman, a co-author on the paper published in March in Naturwissenschaften, a German journal of ecology. “This is the only case we know, but in other places in the world there might be additional plants that use the same adaptions.”
The desert rhubarb grows in the mountainous deserts of Israel and Jordan, where there’s only about 75mm of rainfall each year. Even during the rainy season, the region’s light rainfalls often don’t penetrate the rocky soil of the desert. Plants with large leaves and a deep root system, like the desert rhubarb, typically can’t survive in such an arid climate.
But when the researchers measured the plant’s water absorption during a light rain, they discovered that water infiltrated the soil 10 times deeper around the desert rhubarb then in surrounding areas. Upon closer examination, scientists discovered deep grooves around the plant’s veins, which are coated in a waxy cuticle that helps channel water down to the root.
“Even in the slightest rains,” the researchers wrote, “the typical plant harvests more than 4,300 cubic centimeters of water per year and enjoys a water regime of about 427 millimeters per year, equivalent to the water supply in a Mediterranean climate.”