Navabi A, Singh R P, Tewari J P, Briggs K G
Department of Agricultural, Food, and Nutritional Science, 4-10 Agriculture/Forestry Center, University of Alberta, Edmonton, AB, T6G 2P5, Canada.
CIMMYT, Apdo, 6-641, 06600 Mexico, DF, Mexico.
Plant Dis. 2003 Dec;87(12):1522-1529. doi: 10.1094/PDIS.2003.87.12.1522.
Inheritance of adult-plant resistance to leaf rust, caused by Puccinia triticina, was studied in the progeny of a one-way diallel cross involving five CIMMYT-derived adult-plant resistant wheat (Triticum aestivum) genotypes and a susceptible wheat 'Avocet-YrA'. F progenies, F populations, F-derived F, and F-derived F lines were field evaluated under artificial epidemics with leaf rust race MCJ/SP. Adult-plant resistance to leaf rust was incompletely dominant in crosses with the susceptible parent and was found to be controlled by additive interactions of Lr34 with at least two to three additional genes. Transgressive segregation giving rise to plants or lines with higher and lower levels of resistance than the parents was observed in all F and F derivatives of the resistant-parent intercrosses and suggested that, apart from Lr34, some of the other additive genes were nonallelic. Although specific combining ability was significant in some generations, general combining ability was found to be the major component of variation. Among generations, the estimates of the narrow-sense heritability of adult-plant resistance to leaf rust ranged from 0.67 to 0.97.
对由小麦叶锈菌（Puccinia triticina）引起的成株期叶锈病抗性的遗传进行了研究，该研究以一个单向双列杂交后代为材料，该杂交涉及5个国际玉米小麦改良中心（CIMMYT）培育的成株期抗叶锈病小麦（Triticum aestivum）基因型和一个感病小麦品种‘Avocet-YrA’。在叶锈菌生理小种MCJ/SP的人工接种流行条件下，对F1代、F2群体、F1衍生的F3代和F2衍生的F4代株系进行了田间评价。成株期叶锈病抗性在与感病亲本的杂交中表现为不完全显性，发现由Lr34与至少两到三个其他基因的加性互作控制。在抗性亲本互交产生的所有F2和F2衍生后代中均观察到超亲分离，即出现了抗性水平高于或低于亲本的植株或株系，这表明除Lr34外，其他一些加性基因是非等位的。虽然在某些世代中特殊配合力显著，但一般配合力是变异的主要组成部分。在各世代中，成株期叶锈病抗性的狭义遗传力估计值在0.67至0.97之间。
