Riaz Adnan, Athiyannan Naveenkumar, Periyannan Sambasivam, Afanasenko Olga, Mitrofanova Olga, Aitken Elizabeth A B, Lagudah Evans, Hickey Lee T
Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, St. Lucia, QLD 4072, Australia.
Queensland Alliance for Agriculture and Food Innovation, The University of Queensland; and Commonwealth Scientific and Industrial Research Organization (CSIRO) Agriculture, Canberra, ACT 2601, Australia.
Plant Dis. 2017 Feb;101(2):317-323. doi: 10.1094/PDIS-05-16-0614-RE. Epub 2016 Nov 17.
Leaf rust (LR) caused by Puccinia triticina, is among the most important diseases of wheat (Triticum aestivum L.) crops globally. Deployment of cultivars incorporating genetic resistance, such as adult plant resistance (APR) or all-stage resistance, is considered the most sustainable control method. APR is preferred for durability because it places lower selection pressure on the pathogen and is often polygenic. In the search for new sources of APR, here we explored a diversity panel sourced from the N. I. Vavilov Institute of Plant Genetic Resources. Based on DNA marker screening, 83 of the 300 lines were deemed to carry known APR genes; namely, Lr34, Lr46, and Lr67. Interestingly, lines carrying Lr67 were mostly landraces from India and Pakistan, reconfirming the likely origin of the gene. Rapid phenotypic screening using a method that integrates assessment at both seedling and adult growth stages under accelerated growth conditions (i.e., constant light and controlled temperature) identified 50 lines carrying APR. Levels of APR corresponded well with phenotypes obtained in a field nursery inoculated using the same pathotype (R = 0.82). The second year of field testing, using a mixture of pathotypes with additional virulence for race-specific APR genes (Lr13 and Lr37), identified a subset of 13 lines that consistently displayed high levels of APR across years and pathotypes. These lines provide useful sources of resistance for future research. A strategy combining rapid generation advance coupled with phenotyping under controlled conditions could accelerate introgression of these potentially novel alleles into adapted genetic backgrounds.
由小麦叶锈菌（Puccinia triticina）引起的叶锈病是全球小麦（Triticum aestivum L.）作物最重要的病害之一。采用包含遗传抗性的品种，如成株抗性（APR）或全生育期抗性，被认为是最可持续的防治方法。APR因其对病原体的选择压力较小且通常为多基因控制，所以更有利于持久抗病性。在寻找新的APR来源时，我们在此探索了一个来自N.I.瓦维洛夫植物遗传资源研究所的多样性群体。基于DNA标记筛选，300个品系中有83个被认为携带已知的APR基因，即Lr34、Lr46和Lr67。有趣的是，携带Lr67的品系大多是来自印度和巴基斯坦的地方品种，再次证实了该基因的可能起源。利用一种在加速生长条件（即恒定光照和可控温度）下整合幼苗期和成年期评估的方法进行快速表型筛选，鉴定出50个携带APR的品系。APR水平与在使用相同致病型接种的田间苗圃中获得的表型高度相符（R = 0.82）。在第二年的田间试验中，使用对种族特异性APR基因（Lr13和Lr37）具有额外毒力的致病型混合物，鉴定出13个品系的一个子集，这些品系在多年和多种致病型中始终表现出高水平的APR。这些品系为未来的研究提供了有用的抗性来源。一种将快速世代推进与可控条件下表型分析相结合的策略，可以加速将这些潜在的新等位基因导入适应性遗传背景中。
