Study On Resistance Composition And Genetic Characteristics Of Different Types Wheat Cultivars To Puccinia Striiformis F.sp.tritici

Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici(Pst), is one of the major diseases of wheat in China. It could cause great wheat yield losses due to high variation of Pst and resistance loss for unreasonable use of resistance resources. So it is particularly important to figure out the genetic basis of different types of representative wheat cultivars and utilize resistance resources reasonably to make gene layout. Resistance identification, gene postulation, temperature sensitive resistance detection, classic hybridization analysis were applied on durable resistance cultivars, wheat landraces, slow rusting cultivars and commercial cultivars in southern region of Gansu province in this study to find their genetic components, resistance gene(s), genetic, resistant characteristics and new gene(s), be benificial to analyse the resistance genetic corresponding relation with resistance stability, to discover new genes and provide information for effective utilizing stripe rust resistance resources. The results were as follows:1.The results of resistance identification of 222 wheat materials showed that the resistance components were different in different cultivars against Pst. The resistance of durable resistance cultivars were consisted of all-stage resistance(ASR), adult plant resistance(APR) and temperature sensitive resistance(TSR).The major resistances of wheat landraces were ASR and APR, partial was TSR; ASR was major resistance in commercial cultivars. Some commercial ones had APR. Most of slow rusting cultivars represented APR; What’s more, 51 cultivars were found with TSR.2.APR was steadier than ASR. ASR cultivars mostly contained APR, and they could be manifested as APR when ASR was lost; APR was an important component of slow rusting cultivars and showed steady resistance to new races of Pst。3.After postulating stripe rust resistance genes in 249 cultivars, it was found that 17 cultivars were resistant to all tested races, 94 cultivars carried unknown resistance gene(s).Genes and gene components which tested cultivars might have were also postulated. Furthermore, comparing with the commercial wheat cultivars, the landraces possessed a higher level of genetic diversity and more abundant stripe rust resistance gene(s).4.Seedling genetic analysis showed that there were one pair of dominate genes in Lantian 24, Laozaomai 2, Qingshumai 1 strain1, at least two pairs of dominate genes in Lantian 23, Lantian 27, Sanyuehuang, Qingshumai 1 strain2 and Jinmai 21, at least three pairs of dominate genes in Lantian 18, Lantian 22, Zhongliang 31, Tianxuan 50, Honghuamai 2, Wudubaijianer, Libellula, Xinong85(69), Qingong 3 and Xinong 1376. Their genetic characteristics of resistance and probable source of genes was figured out.The results showed that the cultivars resistance controlled by multiple recessive genes expressed a high level resistance.