Yi H-Y, Rufty R C, Wernsman E A, Conkling M C
Department of Crop Science.
Department of Genetics, North Carolina State University, Raleigh 27695-7620.
Plant Dis. 1998 Dec;82(12):1319-1322. doi: 10.1094/PDIS.1998.82.12.1319.
Random amplified polymorphic DNA (RAPD) analysis was conducted to map the Rk gene in tobacco which conditions resistance to races 1 and 3 of the root-knot nematode, Meloidogyne incognita. Resistant burley tobacco genotype NC 528, containing the Rk gene, and the susceptible cultivar Ky 14 were screened with 1,500 random decamers. A low rate of genetic polymor-phism (<10%) was detected among these lines. Two populations (F and F) of maternally de-rived doubled haploid (MDH) lines of burley tobacco, developed from the cross NC 528 × Ky 14, were used to map the Rk gene. NC 528, Ky 14, three Rk-resistant (Rk-R) DNA bulks, andthree Rk-susceptible (Rk-S) bulks generated from F-derived MDH individuals were screenedwith the primers that amplified bands polymorphic between Rk-R and Rk-S lines. A total of 67 F1MDH lines and 59 F3MDH lines were screened with the primers that amplified bands polymorphic between Rk-R bulks and Rk-S bulks to confirm linkage between candidate markers and the Rk gene. Sixteen RAPD markers were positioned at six loci in a map 24.1 centimorgans long. Six RAPD markers, including one identified in the F3MDH population, were mapped at the Rk locus.
进行了随机扩增多态性DNA（RAPD）分析，以定位烟草中对南方根结线虫1号和3号小种具有抗性的Rk基因。用1500个随机十聚体对含有Rk基因的抗性白肋烟基因型NC 528和感病品种Ky 14进行筛选。在这些品系中检测到的遗传多态性率较低（<10%）。由NC 528×Ky 14杂交产生的两个母本来源的白肋烟双单倍体（MDH）品系群体（F和F）用于定位Rk基因。用能扩增出Rk抗性（Rk-R）和Rk感病（Rk-S）品系间多态性条带的引物，对NC 528、Ky 14、三个Rk抗性DNA混合池以及从F衍生的MDH个体中产生的三个Rk感病混合池进行筛选。用能扩增出Rk-R混合池和Rk-S混合池间多态性条带的引物，对总共67个F1 MDH品系和59个F3 MDH品系进行筛选，以确认候选标记与Rk基因之间的连锁关系。16个RAPD标记位于一张长度为24.1厘摩的图谱的6个位点上。包括在F3 MDH群体中鉴定出的一个标记在内的6个RAPD标记被定位在Rk位点上。
