Interspecific introgression effects on bean breeding germplasm

传统观点认为，现代作物将受益于扩大其遗传多样性的努力。例如，普通干豆（Phaseolus vulgaris）被认为是在两个地理区域独立驯化的，在每次驯化过程中都失去了遗传多样性。为了增加作物种质资源的遗传多样性和引进新性状，植物育种家们将外来材料与常规品种进行杂交。我们的育种计划是将普通豆与尖菜豆进行种间杂交，以引入对引起细菌性枯萎病的黄单胞菌（Xanthomonas axonopodis pv phaseoli）的抗性。从这种种间杂交中获得的第一个抗白叶枯病的品种是OAC Rex。提出的研究计划将验证种间基因渗入对大豆基因组的各种影响，这些影响表现在基因数量、染色体结构和农艺性状的变化上。具体而言，该研究将i)检查尖柄拟虫基因渗入OAC Rex基因组的模式，ii)测试渗入遗传物质的功能，以及iii)确定是否存在可归因于渗入DNA的农艺性状（如作物产量）变化。这些研究将增强对重要栽培物种种间基因渗入对基因组结构影响的总体认识，并有助于评估拓宽作物多样性以促进作物改良的价值。

Conventional wisdom suggests that modern crops would benefit from efforts to broaden their genetic diversity. For example, common dry bean (Phaseolus vulgaris) is believed to have been domesticated, independently, in two geographic regions with losses of genetic diversity during each domestication event. To increase the genetic diversity of crop germplasm and introduce new traits plant breeders have made crosses between exotic materials and conventional varieties. Our breeding program made interspecific crosses between P. vulgaris and Phaseolus acutifolious to introduce resistance to infection by Xanthomonas axonopodis pv phaseoli, which causes bacterial blight, into dry bean. The first bacterial blight resistant variety derived from this interspecific cross was OAC Rex. The proposed research program will test the hypothesis that the interspecific introgression had various effects on the bean genome that are manifested in changes in gene number, chromosome structure and agronomic characteristics. In particular, the study will i) examine the patterns of introgression of P. acutifolius genes into the OAC Rex genome, ii) test the functionality of the introgressed genetic material and iii) determine if there are changes in agronomic traits (such as crop yield) that are attributable to the introgressed DNA. These studies will enhance the general understanding of the consequences of interspecific introgresssion on genome structure in an important cultivated species and help to assess the value of efforts to broaden crop diversity for crop improvement.