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By pressrelease on 11 January 2011
Scientists have identified the genes related to leaf angle in corn (maize) – a key trait for planting crops closer together, which has led to an eight-fold increase in yield since the early 1900s. (Nature Genetics, Jan. 9, 2011.)
The study, led by researchers from Cornell and the U.S. Department of Agriculture – Agricultural Research Service (USDA-ARS) at Cornell and North Carolina State University, is the first to relate genetic variation across the entire maize genome to traits in a genomewide association study. The researchers have so far located 1.6 million sites on the maize genome where one individual may vary from another, and they used those sites to identify the genes related to changes in leaf angle that have allowed greater crop density.
Read more at EurekAlert!
Also in the Jan. 9 online issue of Nature Genetics, a companion paper by the same research team, but led by those at USDA-ARS and North Carolina State University, used the same technique to identify key genes associated with southern leaf blight in maize. The study was funded by the National Science Foundation and USDA-ARS.
Feng Tian, Peter J Bradbury, Patrick J Brown, Hsiaoyi Hung, Qi Sun, Sherry Flint-Garcia, Torbert R Rocheford, Michael D McMullen, James B Holland & Edward S Buckler (2011) Genome-wide association study of leaf architecture in the maize nested association mapping population. Nature Genetics doi:10.1038/ng.746
Kristen L Kump, Peter J Bradbury, Randall J Wisser, Edward S Buckler, Araby R Belcher, Marco A Oropeza-Rosas, John C Zwonitzer, Stephen Kresovich, Michael D McMullen, Doreen Ware, Peter J Balint-Kurti & James B Holland (2011) Genome-wide association study of quantitative resistance to southern leaf blight in the maize nested association mapping population. Nature Genetics doi:10.1038/ng.747
By pressrelease on 9 December 2010
Fungi are a major cause of plant diseases and are responsible for large-scale harvest failure in crops like maize and other cereals all over the world. Together with scientists from the Helmholtz Zentrum in Munich, Regine Kahmann, from the Max Planck Institute for Terrestrial Microbiology in Marburg, and Jan Schirawski, who is now based at the University of Göttingen, analysed the genetic make-up of Sporisorium reilianum, an important maize parasite. Based on a comparison with the genome of a related fungal species, they succeeded in identifying new genes that play an important role in maize infestation. (Science, December 10, 2010)
Read more at EurekAlert…
By pressrelease on 3 November 2010
Photosynthesis is arguably the most impressive feat of nature, where plants harvest light energy and convert it into the building blocks of life at fantastically high efficiency. Indeed modern civilization became possible only with the cultivation of plants for food, shelter and clothing.
While scientists have been able to discover details of the fascinating process by which plants store solar energy as chemical energy, how developing plants build and regulate their solar reactors is still poorly understood. How many genes are involved, and which are the most important? How are different cell types endowed with specific biochemical capacities? What signals fine-tune how much sugar is produced, and which bioproducts are generated? The answers to these questions have applications in agriculture, bioenergy and climate change.
Read more at EurekAlert…
By pressrelease on 28 June 2010
 The research plot on the Iowa State University Agronomy Farm shows how different combinations of cover crop and corn net different results. Early research has shown that with some combinations, almost all corn stover can be removed for biofuels whle yeilds remain high and soil improves. Two years into a study looking at methods of combining a living cover crop between corn rows shows that yield can be maintained at high levels using environmentally friendly practices.
Researchers are testing between-row cover grasses as part of research looking at ways to reduce soil runoff and keep vital nutrients in the soils while crop residue, called stover, is removed from farm fields to produce biofuels.
Continue reading…
By Anastasia on 26 May 2010
In the New York Times on 25 May 10, Sean Carroll shares his wonder at the domestication of teosinte into our favorite crop: Tracking the Ancestry of Corn Back 9,000 Years.
 Teosinte ear (left) and "reconstructed" small primitive maize ear (right). This small-eared form of maize was bred by George Beadle by crossing teosinte with Argentine popcorn and then selecting the smallest segregants. Beadle's intention was to reconstruct a primitive, small-eared corn that would resemble the earliest archeological corn recovered from the Tehuacán valley in Mexico. Doebley, 2001. The most impressive aspect of the maize story is what it tells us about the capabilities of agriculturalists 9,000 years ago. These people were living in small groups and shifting their settlements seasonally. Yet they were able to transform a grass with many inconvenient, unwanted features into a high-yielding, easily harvested food crop. The domestication process must have occurred in many stages over a considerable length of time as many different, independent characteristics of the plant were modified.
Just as amazing as the domestication of maize is the untangling by geneticists of the relationship between teosinte and maize, started by George Beadle in the 1930s. A Brief History of Maize Domestication Studies can be found on Ed Buckler’s lab website.
Beadle proposed the “Teosinte Hypothesis” in which maize is simply a domesticated form of teosinte. He believed that, through artificial selection by ancient populations, several small mutations with relatively large effects could have transformed teosinte into maize. In contrast, Mangelsdorf suggested maize was the product of a hybridization between an undiscovered wild maize and Tripsacum, known as the “Tripartite Hypothesis.”
An extended history of the battle of these two hypotheses can be found in George Beadle’s Other Hypothesis: One-Gene, One-Trait (Doebley, 2001).
Maize researchers can all appreciate the work of early agriculturalists who domesticated maize and those early geneticists whose research built the foundations for our work today. Carroll appreciates them as well: “Every August, I thank these pioneer geneticists for their skill and patience.”
By Anastasia on 5 May 2010
Life without atrazine would complicate weed management in corn, especially for sweet corn growers. A study at the University of Illinois looked at 175 sweet corn fields in the Midwest to find out just how important this 50-year-old, broad-spectrum herbicide is in sweet corn grown for processing.
“If the use of atrazine was phased out completely, our data indicate the greatest burden would be on those growers who rely on less tillage for weed control, have particularly weedy fields, have early season crop production, and grow sweet corn in rotation with other vegetables such as snap or lima beans,” said U of I and USDA Agricultural Research Service ecologist Marty Williams. “Vegetable crops have fewer herbicide options and there tends to be poorer levels of weed control in those crops. When more weeds escape, more weed seed are produced, and crops succeeding those vegetables can have challenging weed problems.”
The U.S. Environmental Protection Agency completed re-registration of atrazine in 2006, but due to controversy over human health and environmental safety concerns, launched a special review and re-evaluation of atrazine last November.
Read more at EurekAlert.
Significance of Atrazine in Sweet Corn Weed Management Systems (pdf) is published in the April-June issue of Weed Technology, a publication of the Weed Science Society of America. Contributors to the study are Chris M. Boerboom and Tom L. Rabaey. Funding was provided by the USDA-Agricultural Research Service.
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