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A study by a team of university and government scientists led by aKansas State University researcher, indicates that genesresponsible for seed shattering - the process by which grassesdisseminate their seeds - were under parallel selection duringsorghum, rice and maize domestication. The study, "Parallel domestication of the Shattering1 genes incereals," was published May 13 in the online version of thejournal, Nature Genetics. In order to identify the molecular basisunderlying seed shattering in sorghum, which is the world's fifthmajor crop, the researchers conducted map-based cloning anddiversity mapping in sorghum first, and then examined theidentified gene in other cereals. Cereal crops, including sorghum, rice and maize were domesticatedfrom their early wild progenitors by humans thousands of years ago,because of their importance as a food source, said Jianming Yu,associate professor of agronomy at Kansas State University. Although these crops were domesticated by human groups in differentgeographical regions, they all underwent systemic and parallelchanges during the domestication process. "Once we better understand seed shattering in sorghum, the betterwe will understand seed shattering and domestication in othercereal crops," Yu said. "Moreover, as the demands for food, feedand fiber increase, domesticating other grasses into crops wouldalso benefit from the current research findings." The implications for sorghum alone are huge, because of sorghum'semerging applications in bioenergy and stress management, as wellas its long-time importance as a food and feed source, he said. A better understanding about the origins of sorghum, a very diversespecies, helps in terms of preserving natural resources forbreeding use, classifying germplasm, and facilitating the processof bringing useful genes from wild relatives to crops. Seeds on wild grasses shed naturally when they mature, whichensures their natural propagation, Yu said. When humans begancultivating those crops, however, seed shattering would have causedinefficient harvesting and large losses in grain yield, becausesome of the seeds which were to be harvested, would have alreadydisbursed naturally. "Selection for non-shattering crop plants would have greatlyfacilitated harvesting and improved production," said Zhongwei Lin,research associate in agronomy at Kansas State and the first authorof the publication. He noted that several other genes have been identified as beingresponsible for seed shattering in rice and wheat. Prior to thiscurrent study, however, no systematic findings have been made onwhether other cereals share the same molecular genetic basis forshattering, although such hypothesis was proposed more than adecade ago. The highly similar genomes of these cereals and thecritical role of non-shattering in their domestication make thisspeculation plausible. The researchers found that seed shattering in sorghum is controlledby a single gene, Sh1. That finding, paired with findings ofconserved collinearity - genes and their orders are similar oncorresponding chromosome segments from different species - ofgenomic regions containing the Sh1 orthologs (genes can be tracedback to the same ancestral copy) across several cereals, theidentification of the rice OsSh1 and the structural variation andquantitative trait locus analyses of the two maize orthologs(ZMSH1-1 and ZMSh1-5.1+ZmSh1-5.2) suggest that the Sh1 genes forseed shattering have undergone parallel selection duringdomestication in multiple cereals. "It is great to have this team of scientists with complementaryexpertise in different species to work on this project," said FrankWhite, professor of plant pathology at Kansas State University. To identify the molecular basis underlying seed shattering insorghum, the team constructed a large population from a crossbetween a wild sorghum with complete seed shattering, Sorghumvirgatum (SV), and a non-shattering domesticated sorghum line,Tx430. Once the gene was pinpointed, they moved on to a diverse setof sorghum lines and landraces to examine how many differentversion of domesticate copy of Sh1 exist. Not surprising, they found three different ones, which corroboratedthe earlier inference of multiple origins of sorghum in differentparts of the African continent from morphology characteristics. Other Kansas State University researchers include Xianran Li,research associate in agronomy and Tesfaye Tesso, assistantprofessor of agronomy, as well as Harold Trick, professor of plantpathology, and Jiarui Li, research assistant professor and ZhaoPeng, Ph.D. candidate - both in plant pathology. The team alsoincluded researchers from the University of Wisconsin-Madison, IowaState University, USDA-ARS, University of Nebraska-Lincoln, andPurdue University. The e-commerce company in China offers quality products such as Dental Implant Prosthetics Manufacturer , Porcelain Fused To Metal, and more. For more , please visit Crowns And Bridges today!
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