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Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Potential chromosomal introgression barriers revealed by linkage analysis in a hybrid of Pinus massoniana and P. hwangshanensis | Li et al. BMC Plant Biology 2010 10 37 http www.biomedcentral.com 1471-2229 10 37 BMC Plant Biology RESEARCH ARTICLE Open Access Potential chromosomal introgression barriers revealed by linkage analysis in a hybrid of Pinus massoniana and P. hwangshanensis Shuxian Li Ying Chen Handong Gao Tongming Yin Abstract Background Exploring the genetic mechanisms underlying speciation is a hot topic in modern genetics and evolutionary studies. Distortion of marker transmission ratio is frequently ascribed to selection against alleles that cause hybrid incompatibility. The natural introgression between P. massoniana and P. hwangshanensis and their distribution ranges lead to the emergence of the two species as desirable organisms to study the genetic mechanisms for speciation. Results Using seeds sampled from trees at different elevations we consistently detected sharp decreases in seed germination rates of trees in the hybrid zone which might be due largely to the hybrid incompatibility. A genetic map was established using 192 megagametophytes from a single tree in the hybrid zone of the two species. Segregation distortion analysis revealed that the percentage of significant-segregation-distortion SSD markers was extremely high accounting for more than 25 of the segregating markers. The extension range the distortion direction and the distortion intensity of SSD markers also varied dramatically on different linkage groups. Conclusions In this study we display the potential chromosomal introgression barriers between P. massoniana and P. hwangshanensis. Our study provides a valuable platform for conducting genome-wide association of hybrid incompatible QTLs and or candidate genes with marker transmission ratio distortion in the hybrid. Background A biological species is defined as a group of natural populations that mate and produce offspring with one another but do not breed with other populations. Yet biologists have argued over the details of the definition since around .
