Development of wheat-rye 4R chromosome translocation lines and assignment of its powdery mildew resistance

【摘要】：Rye(Secale ceraele L.) is an important gene donor for wheat improvement because of its many valuable traits,especially disease resistance Development of novel wheat-rye translocations with disease resistance can contribute to transferring the resistance into common wheat.In a previous study,a wheat-rye T4 BL-4 RL and T7 AS-4 RS translocation line,WR41-1,was developed by distant hybridization,and it was speculated that its resistance to powdery mildew,caused by Blumeria gra,minis f.sp.tritici(Bgt),was derived from rye based on pedigree analysis To make accurate use of chromosome 4 R in wheat improvement,a set of new 4 R translocations involving different arm translocations,such as 4 RS monosomic,4 RL monosomic,4 RL disomic,4 RS monosomic plus 4 RL monosomic,4 RS monosomic plus 4 RL disomic,and 4 RS disomic plus 4 RL disomic translocations,were developed from crosses with common wheat.Those translocations were characterized by genomic in situ hybridization(GISH) and EST-SSR(expressed sequence tag-simple sequence repeat) marker analysis.To confirm the source of powdery mildew resistance,the translocation plants were tested against Bgt isolate E09,the results indicated that all translocations with 4 RL were resistant at all tested growth stages;while those with only 4 RS translocation or no alien translocation were susceptible.This indicated that the powdery mildew resistance of WR41-1 was derived from the alien chromosome arm 4 RL.To effectively use the 4 RL resistance in wheat improvement,two kompetitive allele specific PCR(KASP) markers specific for chromosome arm 4 RL were developed to detect the alien chromosome in the wheat genome.These new translocation lines with diagnostic markers can efficiently serve as important bridges for wheat improvement.