The genetics of blackleg [Leptosphaeria maculans (Desm.) Ces, et De Not.] resistance in rapeseed (Brassica napus L.)
The genetics of blackleg [Leptosphaeria maculans (Desm.) Ces, et De Not.] resistance in rapeseed (Brassica napus L.)
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DOI：
10.1007/bf00224096
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发表时间：
1996-10
影响因子：
5.4
通讯作者：
E. Pang;G. Halloran
中科院分区：
文献类型：
--
作者：
E. Pang;G. Halloran
成虫黑腿病的遗传控制[j]。消费类电子展。et De Not。在“Maluka”（黑足抗性）与“Niklas”（高度敏感）杂交的f2和一次回交群体中研究了油菜（Brassica napusL.）的黑足抗性。在所有接种中均使用具有高水平宿主特异性（MB2）的AL. maculansisolate。采用冠溃疡病大小的三个单独测量方法来评估耐药性/敏感性，即冠环的百分比（%G）、外部病变长度(E)和内部病变面积（%II）。基于E和%II的f2和首次回交群体的疾病严重程度评分呈不连续分布，表明这些抗性措施受主基因控制；而%G是连续的，说明该措施存在定量遗传控制。在f2和第一次回交群体中，对（不明确的）抗性等级（基于E）进行的卡方检验表明，抗性可能由单个不完全显性的主基因控制。虽然基于%II的f2和第一次回交群体的分布明显不连续，但观察到的抗性和敏感性分离比不符合所考虑的众多孟德尔比率中的任何一个。讨论了不同评估方法和采用的黑腿分离物在抗性遗传上的差异。
The genetic control of adult-plant blackleg [Leptosphaeria maculans(Desm.) Ces. et De Not.] resistance in rapeseed (Brassica napusL.) was studied in the F2and first-backcross populations of the cross “Maluka” (blackleg-resistant) x “Niklas” (highly susceptible). AL. maculansisolate possessing high levels of host specificity (MB2) was used in all inoculations. Resistance/susceptibility was evaluated using three separate measures of crown-canker size, i.e. the percentage of crown girdled (%G), external lesion length (E) and internal lesion area (%II). Disease severity scores for the F2and first-backcross populations based on E and %II gave discontinuous distributions, indicating major-gene control for these measures of resistance; but those for %G were continuous, indicating quantitative genetic control for this measure. Chi-square tests performed on the (poorly-defined) resistance classes, based on E, in the F2and first-backcross populations indicated the likelihood for resistance being governed by a single, incompletely dominant major gene. Although the distributions of the F2and first-backcross populations, based on%II, were clearly discontinuous, the observed segregation ratios for resistance and susceptibility did not fit any of the numerous Mendelian ratios which were considered. Differences in inheritance of resistance according to the assessment method and blackleg isolate used, were discussed.