Pathotype-related Molecular Markers Of Two Species Of Cereal Cyst Nematode

Cereal cyst nematode(CCN)is one of the important pathogenic nematodes which endanger the cereal crops in temperate zone,and it caused serious influence of the yield and quality.The disease 1s easy to be ignored because of its hazard symptoms are similar to the symptoms of yellow dwarf,uneven fertilizer,lack of fertilizer,lack of nutrition.It has been happened and damaged in 16 provinces of China,which threaten the food security seriously and is accelerating to spread.Planting resistant cultivars is detennined as the most economical and effective method to control CCN,and the identification of pathotypes is important for breeding and utilization of disease-resistant varieties.But the traditional procedure of pathotype identification is complex and time-consuming,and its results are easily influenced by outside conditions.Therefore it is necessary to establish a system of rapid detection based on lnolecular techniques to improve the identification accuracy and shorten the identification period.5 pathotypes including 9 CCN populations from huang?huai floodplain were analyzed using RAPD and ISSR techniques.In order to establish a kind of rapid,convenient,and accurate method based on SCAR markers.The 9 populations were Xingyang,Baoding,Shangqiu,Anyang,Qingfeng,Qixian,Xuchang,Huaiyang and Boai populations.Furthennore.added 8 populations of CCN to detecting specificity of SCAR markers.The 8 populations were:Handan,Zhalantun,Keshiketeng,Heze,Gaotang,Shangma,Lingbi and Xiaoxian popolations.The main results of this study are as follows:331 random primers were screened and 3 random primers with RAPD method were found related to Xingyang population,1 random primer was found releted to Baoding and Shangqiu populations,3 random primers were found related to Xuchang population,3 random primers were found related to Huaiyang and Boai populations.Primer S10,S43,S112 could product polymorphic bands of Xingyang population about 750bp,1200bp and 800bp respectively.Primer S83 could product polymorphic bands of Baoding and Shangqiu populations about 350bp.Primer S86,S170,S178 could product polymorphic bands of Xuchang population about 550bp,I600bp and 1200bp respectively.Primer S48,S232,S278 could product polymorphic bands of Huaiyang and Boai populations about 600bp,550bp and 1700bp respectively.Among the RAPD markers,3 markers of the CCN pathotype of Xingyang population and 2 markers of the CCN pathotype of Xuchang population had been transformed into SCAR markers successfully.The polymorphic bands were cloned and sequencd.The polymorphic band of S10,S43,S1 12,S86 and S178 were 735bp,1182bp,857bp,539bp and 1135bp.According to the sequencing results,5 pairs of specific primers were designed.After PCR amplification,the results indicated that the specific primers based on S10,S43,S112 could amplify specific bands only in Xingyang population,the specific primers based on S86,S178 could amplify specific bands only in Xuchang population.This proved that the 5 SCAR markers are specific,which can be used to detect the CCN pathotypes of Xingyang and Xuchang populations.57 ISSR primers were screened and 3 ISSR markers were found related to Xingyang populationg of CCN.Primer UBC810,UBC811,UBC813 could amplify polymorphic bands about 1900bp,1400bp and 1800bp respectively.Among the ISSR markers,the polymorphic band of UBC8l0 which was 1757bp had been transformed into SCAR markers successfully.A pair of specific primers were designed and only the Xingyang population could amplify the specific band.This proved that the SCAR marker is specific,it can be used to detect the CCN pathotype of Xingyang population.