Sharma Brij B, Kalia Pritam, Singh Dinesh, Sharma Tilak R
Division of Vegetable Science, Indian Council of Agricultural Research-Indian Agricultural Research InstituteNew Delhi, India.
Division of Plant Pathology, Indian Council of Agricultural Research-Indian Agricultural Research InstituteNew Delhi, India.
Front Plant Sci. 2017 Jul 18;8:1255. doi: 10.3389/fpls.2017.01255. eCollection 2017.
Black rot caused by pv. () is a very important disease of cauliflower ( group) resulting into 10-50% yield losses every year. Since there is a dearth of availability of resistance to black rot disease in (C genome), therefore exploration of A and B genomes was inevitable as they have been reported to be potential reservoirs of gene(s) for resistance to black rot. To utilize these sources, interspecific hybrid and backcross progeny (B) were generated between cauliflower "Pusa Sharad" and Ethiopian mustard "NPC-9" employing embryo rescue technique. Direct ovule culture method was better than siliqua culture under different temperature regime periods. Hybridity testing of F inter-specific plants was carried out using co-dominant SSR marker and B and C genome-specific (DB and DC) primers. Meiosis in the di-genomic (BCC) interspecific hybrid of group (2 = 18, CC) × (2 = 4x = 34, BBCC) was higly disorganized and cytological analysis of pollen mother cells revealed chromosomes 2 = 26 at metaphase-I. Fertile giant pollen grain formation was observed frequently in interspecific F hybrid and BC plants. The F inter-specific plants were found to be resistant to race 1. Segregation distortion was observed in BC generation for black rot resistance and different morphological traits. The At1g70610 marker analysis confirmed successful introgression of black rot resistance in interspecific BC population. This effort will go a long way in pyramiding gene(s) for resistance against black rot in Cole crops, especially cauliflower and cabbage for developing durable resistance, thus minimize dependency on bactericides.
由野油菜黄单胞菌致病变种（Xanthomonas campestris pv. campestris）引起的黑腐病是花椰菜（Brassica oleracea group）的一种非常重要的病害，每年导致10%-50%的产量损失。由于甘蓝（Brassica oleracea，C基因组）中缺乏对黑腐病的抗性，因此对A和B基因组进行探索是不可避免的，因为据报道它们是抗黑腐病基因的潜在储存库。为了利用这些资源，采用胚挽救技术在花椰菜“Pusa Sharad”和埃塞俄比亚芥“NPC-9”之间产生了种间杂种和回交后代（BC）。在不同温度条件下，直接胚珠培养法优于角果培养法。使用共显性SSR标记以及B和C基因组特异性（DB和DC）引物对种间F植株进行杂种性检测。甘蓝组（2n = 18，CC）×埃塞俄比亚芥（2n = 4x = 34，BBCC）的双基因组（BCC）种间杂种的减数分裂高度紊乱，花粉母细胞的细胞学分析显示在中期I染色体数为2n = 26。在种间F杂种和BC植株中经常观察到可育的巨型花粉粒形成。发现种间F植株对小种1具有抗性。在BC代中观察到黑腐病抗性和不同形态性状的分离畸变。At1g70610标记分析证实黑腐病抗性已成功导入种间BC群体。这项工作将大大有助于在十字花科作物，特别是花椰菜和甘蓝中聚合抗黑腐病基因，以培育持久抗性，从而减少对杀菌剂的依赖。
