Genetic variation of bread wheat accessions in response to the cereal cyst nematode, Heterodera filipjevi

Abstract

SummaryBread wheat,Triticum aestivum, produces large edible grains and is consumed by 75% of the world’s populations. Cereal cyst nematodes have a global distribution and cause significant economic yield losses in many countries. Therefore, there is an urgent need to identify new resistance sources. In this study, the genetic diversity of 43 wheat accessions in response to cereal cyst nematode,Heterodera filipjeviIsfahan pathotype, was assessed using a simple sequence repeat (SSR) marker. Seven primers were used, out of which five primers showed polymorphisms. Alleles per primer varied from one to three per locus (mean 2.85). The highest and lowest polymorphic information content of 0.81 and 0.44 (mean 0.66) were related to Xgwm 3012DL and Xgwm147, respectively. Genetic similarity was 29-88% between accessions. SSR analysis divided the accessions into five main groups. Resistant cultivars ‘Bam’ and ‘Behrang’ possessed bothCre1 andCre8 resistant genes. TheCre3 andCatgenes were partially sequenced in five cultivars of different responses toH. filipjevi. The nucleotide sequences were compared toCre3 andCathomologues, indicating 93-100% and 86-92% homology, respectively. The MEGA program showed highest similarity ofCre3 andCatgenes amplified with the resistance gene analogues (RGA14) in the wheat andCat3-A1 gene in ‘Carnamah’. This research showed that SRR markers could efficiently verify genetic diversity between wheat accessions, and the known resistance genes (Cregenes) against the cereal cyst nematodes could not control theH. filipjeviIsfahan pathotype populations, except theCre1 gene.