Evaluation Of Wheat Cultivars Resistance To Heterodera Avenae And Research On Resistance Mechanism Of The Wheat To Cereal Cyst Nematode

The cereal cyst nematode (CCN) of wheat has become a severe disease in recent years. Heterodera avenae is widely distributed in China. This article studied the species of three CCN populations in Beijingcaiyu, Shandongfeicheng and Henantangyin wheat plant area and pathotypes of the CCN populations in Beijingcaiyu, and the resistance of cultivars to Beijingcaiyu populations in the field and expression analysis of superoxide dismutase (SOD) gene after inoculating Heterodera avenae.The molecular characteristics of cysts’ DNA were measured with rDNA-ITS-RFLP and SCAR. The results showed that the population in Beijingcaiyu, Shandongfeicheng and Henantangyin were identified as Heterodera avenae, not Heterodera filipjevi.For screening resistant resources in breeding to H. avenae, the resistance of85wheat germplasm cultivars or lines from CIMMYT and34wheat germplasm lines from home was evaluated in soil using the number of cyst per plant, with the nematode from Caiyu population, Beijing, China. And the pathotypes of Caiyu populations of CCN in Beijing wheat plant area was identified by using the International Host Differentials Set (IHDS). No cultivar was immune to H. avenae. However, CROC-1/AE.SQUARROSA(225)//OPATA, VP1620, MILAN,6R(6D), ID-2150, CROC-1/AE.SQUARROSA(224)//OPATA were highly resistant. KATE A-1, MACKELLER, SUNCO/2*PASTOR, CANADIAN/CUNNINGHAM//KENNEDY etc. were moderately resistant to H. avenae, which were from CIMMYT. The wheat germplasm cultivars or lines from home were almost susceptible and only a few were resistansis. The results indicated that the pathotypes of Caiyu populations of CCN was similar to the pathotypes of Australia, which was Hal3.Expression analysis of superoxide dismutase (SOD) gene from different resistance wheat varieties root at different time after inoculating Heterodera avenae, was carried by semi-Q RT-PCR, using wheat Actin gene as a control. The result showed that the quantity of superoxide dismutase gene expression obvious increased after inoculation, and the expression level in resistant cultivars was more than that of susceptible varieties. The expression in susceptible and resistant varieties at84h after inoculation were getting lower and lower, but the expression level in resistant cultivars was higher than that of susceptible cultivars. The results of SOD gene expression demonstrated that SOD play an important role in the defence mechanism against H. avenae in resistant wheat varieties.