Molecular Mapping Of A Wheat Stripe Rust Resistance Gene Derived From Aegilops Variabilis

The virulence of wheat strip rust varies frequently and produces new virulent races that leads to the breakdown of resistance genes and thus threatens wheat production.Possible solution for this problem for a long-term strategy is to explore and utilize new resistance genes with durable resistance by pyramiding adult plant resistance.We transferred adult-plant resistance gene from Aegilops variabilis AS24 into common wheat 3854?susceptible?background.The lines NZ238?resistance?and NZ242?susceptible?derived from AS24/3854//3854 BC1F₈ were used in the present study.Their F₂ and F_2:3:3 populations were used to develop linkage molecular markers.The main results are as follows:On basis of field resistance evaluation,Ae.variabilis AS24,NZ238 and NZ238/NZ242hybrid F₁ showed resistance to stripe rust at adult stage?infection type 1-2?;while 3854and NZ242 was susceptible to stripe rust at adult stage?infection type 8-9?.The segregation ratio of F₂ and F_2:3:3 populations between NZ238 and NZ242 were in accordance with the ratio of 3:1 and 1:2:1 by the chi-square test respectively.Therefore,the disease resistance is controlled by a dominant single gene.We developed specific molecular markers on the wheat 2AS deletion fragment for the purpose of resistance breeding Three co-segregated markers for the new gene were obtained.The transfer of Ae.variabilis AS24 containing the new gene is involved in a replacing of about 25.4Mb on wheat chromosome arm 2AS.The introgressed alien chromosome fragment do not harbor tough glume gene locus.Therefore,this wheat with the new gene has important significance in wheat disease resistance breeding.