Identification of RAPD and ISSR markers associated with flag leaf senescence under water- stressed conditions in wheat (Triticum aestivum L.)

摘要

Time of flag leaf senescence is an important determinant of yield under stress and optimal environments. A segregating population from a cross between drought sensitive genotype (Variant-1) and drought tolerant genotype (Veery), was made to identify molecular markers linked to flag leaf senescence gene in wheat under water-stressed conditions as indicator for drought tolerance. Thirty eight RAPD and twenty-five ISSR primers were tested for polymorphism among parental genotypes and F2 population. The present study indicated that four RAPD and two ISSR markers linked to the flag leaf senescence gene in wheat. QTLs for flag leaf senescence were associated with RAPD markers (Pr11230bp, Pr19240bp, OPU06340bp and OPH13450bp) and explained 7.0%, 50.0%, 24.0% and 13.0% of the phenotypic variation, respectively. QTLs for flag leaf senescence were also associated with ISSR markers (M11100bp and AD2300bp.) and explained 25% and 34% of the phenotypic variation, respectively. The RAPD markers (Pr11230bp, Pr19240bp, OPU06340bp and OPH13450bp) have genetic distance of 15.6, 15.0, 13.2 and 17.4 cM from flag leaf senescence gene, respectively. The ISSR markers (M11100bp and AD2300bp) also showed the genetic distance of 12.5 and 10.2 cM from flag leaf senescence gene, respectively. Therefore, these four RAPD and the two ISSR markers were linked to the QTL for the flag leaf senescence gene as indicator of drought tolerance. These markers can be used in wheat breeding programs, as a selection tool in early generations.