美國農(nóng)業(yè)研究局（ARS）的科研人員近日發(fā)明了一種新的方法來破譯本土草原上被廣泛研究的一種草——柳枝稷（Switchgrass）的遺傳特性。ARS位于加利福尼亞西部研究中心的克里斯蒂安.托比亞斯（Christian Tobias）及其同事在《遺傳學》（Genetics）上發(fā)表的柳枝稷遺傳圖譜,，有望加快尋找能夠提高柳枝稷作為生物能源可靠來源的基因。
柳枝稷目前主要作為家畜的牧草,，并可以用來修復貧瘠的土壤。但是近年來,，由于它可以通過燃燒發(fā)電并且可以轉(zhuǎn)變成乙醇，逐漸引起科研人員的興趣,。
為了繪制柳枝稷遺傳圖譜,，研究人員采用了全同胞圖譜繪制法（full-sib mapping），即以柳枝稷推廣品種Kanlow為母本,，ARS培育的品種Alamo為父本進行雜交,，得到了238棵F1代；進一步從F1群體中提取DNA并利用1000多個遺傳標記完成了圖譜的繪制,。此圖譜將柳枝稷的基因組分成了18個不同的組,，每組的基因位于同一條DNA鏈上。
弄清柳枝稷的遺傳結構能夠帶來巨大的好處,。為使柳枝稷作為一種生物燃料進一步推廣,，科學家正在探索提高其產(chǎn)量并使其細胞壁更容易破裂的方法，這是從纖維質(zhì)生產(chǎn)乙醇必要的一步,。
柳枝稷的遺傳圖譜有助于發(fā)現(xiàn)與細胞壁組成,、作物產(chǎn)量和其他有用特性相關的基因?？茖W家通過比較柳枝稷和水稻,、高粱及其他植物的遺傳圖譜，可以更好地理解基因組,，找到和植物中特殊品質(zhì)相關的基因,。(生物谷Bioon.com)
生物谷推薦原文出處：
Genetics doi:10.1534/genetics.110.113910
Complete Switchgrass Genetic Maps Reveal Subgenome Collinearity, Preferential Pairing and Multilocus Interactions
Miki Okada*,1, Christina Lanzatella*, Malay C. Saha, Joe Bouton, Rongling Wu and Christian M. Tobias*,2
* U. S. Department of Agriculture–Agricultural Research Service (USDA–ARS), Genomics and Gene Discovery Research Unit, Western Regional Research Center, Albany, California 94710, Samuel Roberts Noble Foundation, Inc., Forage Improvement Division, Ardmore, Oklahoma 73401 and Division of Biostatistics, Pennsylvania State University, Hershey, Pennsylvania 17033 ；2 Corresponding author: Genomics and Gene Discovery Research Unit, Western Regional Research Center, 800 Buchanan St., Albany, CA 94710.
Polyploidy is an important aspect of the evolution of flowering plants. The potential of gene copies to diverge and evolve new functions is influenced by meiotic behavior of chromosomes leading to segregation as a single locus or duplicated loci. Switchgrass (Panicum virgatum) linkage maps were constructed using a full-sib population of 238 plants and SSR and STS markers to access the degree of preferential pairing and the structure of the tetraploid genome and as a step toward identification of loci underlying biomass feedstock quality and yield. The male and female framework map lengths were 1645 and 1376 cM with 97% of the genome estimated to be within 10 cM of a mapped marker in both maps. Each map coalesced into 18 linkage groups arranged into nine homeologous pairs. Comparative analysis of each homology group to the diploid sorghum genome identified clear syntenic relationships and collinear tracts. The number of markers with PCR amplicons that mapped across subgenomes was significantly fewer than expected, suggesting substantial subgenome divergence, while both the ratio of coupling to repulsion phase linkages and pattern of marker segregation indicated complete or near complete disomic inheritance. The proportion of transmission ratio distorted markers was relatively low, but the male map was more extensively affected by distorted transmission ratios and multilocus interactions, associated with spurious linkages.
