关键词: 小麦条锈病, 抗性鉴定, 遗传多样性, Yr基因检测

Abstract:

【Objective】The objective of this study is to understand the resistance level to stripe rust and genetic diversity of wheat cultivars (lines), master the utilization of stripe rust resistance genes, and to lay a foundation for wheat breeding and rational utilization of new cultivars with excellent resistance to stripe rust.【Method】A total of 103 wheat cultivars (lines) were identified by physiological races CYR32, CYR33 and CYR34 singly at seedling stage and CYR32 at adult stage. SSR molecular marker technique was used to evaluate the genetic diversity and the molecular markers of the important known resistance genes of wheat stripe rust Yr5, Yr9, Yr10, Yr15, Yr18 and Yr26 were used to detect the stripe rust resistance genes in the tested wheat cultivars (lines).【Result】The identification of seedling resistance showed that 20 out of 103 cultivars (lines) were resistant to physiological race CYR32, accounting for 19.42% of the tested materials; 34 cultivars (lines) showed resistance to CYR33, accounting for 33.01% of the tested materials; 36 cultivars (lines) showed resistance to CYR34, accounting for 34.95% of the tested materials; only six cultivars including Zheng 6 fu, Ningmai 3, Laolanmai, Jing 411, Jingzuo 278 and Yangmai 158 showed resistance to all the three physiological races CYR32, CYR33 and CYR34. The identification by CYR32 at adult stage showed that 55 cultivars (lines) such as Zhengzhou 021 had adult plant resistance, accounting for 53.40% of the tested materials. Genetic diversity analysis showed that the variation of genetic similarity coefficient of 103 cultivars (lines) ranged from 0.50 to 0.93, with an average of 0.66. Cluster analysis found that 103 cultivars (lines) were divided into three categories. The first category included four cultivars, namely Huapei 112-2, Jubilejina Ⅱ, Luzhan 1 and Elkhart. The second category included 43 cultivars (lines), among which the cultivars (lines) from the same region or with the same pedigree source were clustered in the same category, indicating that there was a certain relationship between the genetic relationship and the source. In the third category, the cultivars (lines) with the same pedigree were all clustered in one sub-category, indicating that the same or similar materials were mostly used in the breeding process of wheat cultivars in the same region and it resulted in the similar genetic relationship among wheat cultivars. The detection of known resistance genes suggested that Yr9, Yr10, Yr18 and Yr26 existed in 15, 8, 19 and 1 cultivars, respectively. Yr5 and Yr15 were not detected in the cultivars (lines).【Conclusion】The resistance level of the cultivars (lines) was low at seedling stage. Six cultivars, Zheng 6 fu, Ningmai 3, Laolanmai, Jing 411, Jingzuo 278 and Yangmai 158, may contain unknown all stage resistance genes, which are suitable for the control of wheat stripe rust in cultivar rotation planting. The resistance at adult stage was better and the frequency of Yr18 detection was higher. Therefore, wheat breeding should make full use of high-quality known resistant resources, explore new resistant materials, and cultivate durable resistant cultivars of multi-gene combination.

Key words: wheat stripe rust, resistance identification, genetic diversity, Yr gene detection