Identihcation Of The New Source Of Resistance To Cereal Cyst Nematode In The Wheat-triticale Derivatives

Wheat（Triticum aestivum L.）is one of the three most important staple crops inChina. The narrowness of genetic basis of gene resources limits the improvement ofwheat yield and disease resistance. Wheat relative species possess many useful genes.The introgression of these genes from wild relative species by means of widehybridization and chromosome engineering is important in improving wheatproduction. In this study, morphological and cytological analyses were performed tocharacterize the progeny lines derived from the cross between the common wheatcultivar and octoploid triticale cultivar Jinsong5. The chromosomal compositions ofthese lines were analyzed using SSR markers. The objective of this study was toidentify wheat-triticale lines with resistance to cereal cyst nematode and powderymildew for improving disease resistance.Morphological observation indicated that some of the progeny lines displayedthe intermediate types of the two parents, while the others resembled and/or weresuperior to both parents. Results of chromosome counting and the configuration ofchromosomes during meiosis indicated that the five progeny lines were chromosomeaddition lines （2n=44）.Analysis of SSR markers identified31polymorphic markers between Jingdong8wheat and Jinsong5triticale out of273markers. Three markers amplified thebanding patterns specific to triticale but not to the common wheat cultivar. Thisindicates that the progeny lines contained the chromatin from triticale.Assessment of powdery mildew resistance indicated that Jingdong8was highlysusceptible to isolate E09of Blumeria graminis f. sp. tritici E09, while the triticalecultivar Jinsong5was highly resistant to this isolate. The progeny lines H4, H5, H7,H8and H9were highly susceptible. Since the genes effective against isolate E09were Pm17on chromosome1R and Pm20on chromosome6R, the rye chromosomesin the progeny lines were possibly not chromosomes1R or6R.Results of cereal cyst nematode test demonstrated that Jingdong8and H9weremoderately resistant to the Zhengzhou population of H. avenae, while Jinsong5 triticale was highly resistant to this pathotype of H. avenae. The progeny lines H4, H5and H7were highly resistant, but line H8was moderately susceptible. Based on theresults from this study, the triticale cultivar Jinsong5and its progeny lines can beused as a new source of resistance to cereal cyst nematode.