Identification On The Species And Pathotypes Of Three Cereal Cyst Nematode Populations From The Middle Area Of Henan Province And Screening Of Resistant Cultivars To Two Populations

As a potential serious constraint to wheat production，the cereal cyst nematodes(CCN) happened seriously in the middle of Henan. According to species and pathogenicidentification results, the resistant varieties were determined as the most effective method tocontrol CCN. This article studied the species and pathotypes of three CCN populations from themiddle of Henan and appraised resistance of the wheat cultivars to Qixian of Kaifeng and Linyingof Luohe populations in pot. The chief research results were as follows：According to Morphology and Molecular Biology methods, three CCN populations fromYanjin of Xinxiang, Qixian of Kaifeng and Liying of Luohe were identified. The morphologicalcharacteristics of cysts and the second juvenile of Yanjin of Xinxiang and Qixian of Kaifengpopulations accord with H. avenae, while the Linying of Luohe population accord with H. filipjevi.The cyst of Linying population has distinct under-bridge in the vulval cone area, but Yanjin ofXinxiang and Qixian of Kaifeng populations don’t have it. The ITS-PCR outcomes of three CCNpopulations digested by8restriction enzymes, we found the same fragments between Yanjin ofXinxiang and Qixian of Kaifeng populations which accord to H. avenae type C. The fragments ofLiying of Luohe population accord to H. filipjevi completely. The results of ITS sequencesanalysis and alignments by MP of MEGA4showed that Yanjin of Xinxiang and Qixian ofKaifeng populations might be have the most close relationship with H．avenae and the sequence ofLinying of Luohe population have a close relationship with H. filipjevi. Based on morphologicaland molecular characteristics of three CCN populations, the Yanjin of Xinxiang and Qixian ofKaifeng populations were identified as H. avenae, and the Liying of Luohe population wasidentified as H. filipjevi.The pathotypes of the three populations of CCN were identified by the International HostDifferentials Set (IHDS). The results showed that the pathotypes of these populations are differentfrom ones which have been nominated formally. Yanjin of Xinxiang and Qixian of Kaifengpopulations have coincident virulence according to the standard international of group A, and thetwo populations have nearly coincident virulence according to the standard international of groupB. The two populations of Yanjin of Xinxiang, Qixian of Kaifeng belong to the same pathotype with the five populations of Qingfeng of Puyang, Anyang, Handan, Heze and Yingshang ofFuyang which have been reported for the coincident virulence according to the standardinternational of group A. The same pathotype maybe belong to Ha1group of H. avenae. Linyingof Luohe population and Luolong of Luoyang population belong to Hfc-2pathotype of H. filipjevi.for the coincident virulence according to the standard international.The main wheat cultivars in Kaifeng and Luohe were evaluated by J2inoculation in pot tostudy their resistance to Qixian of Kaifeng population and Linying of Luohe populationsrespectively. The results showed that the resistance of different cultivars to same population wassignificantly different, and the resistance of the same cultivar to two populations was different.There were no immune cultivars to Qixian of Kaifeng population in the tested42cultivars.Zhongyu6were high resistant and accounting for2.4%in all of the tested cultivars. Pumai9,Xinmai19, Yumai18, Xinmai18, Fengwu981, Zhengyumai9987, Kaimai18, Luomai4-168, Xuke1,Zhoumai19, Zhoumai16were resistant and accounting for26.2%in all tested cultivars. Therewere no immune cultivars in the tested41cultivars to Linying of Luohe population. Zhongyu6were high resistant and accounting for2.4%in all tested cultivars. Pumai9, Yunong949wereresistant and accounting for4.9%in all tested cultivars. Thus we can consider promoting Zhongyu6and Pumai9in the two districts in hope of finding economic and effect ways against CCN there.