Evaluation of D-genome synthetic hexaploid wheats and advanced derivatives for powdery mildew resistance

The present study was undertaken to characterize 32 d-genome synthetic hexaploid wheats (shws) of an elite-ii subset and their 60 advanced derivatives. at seedling stage under controlled glasshouse conditions in murree,the shws showed complete resistance/ immune to susceptible disease reactions viz.,two (6.25%) were immune,eighteen (56.25%) were resistant,nine (28.12%) were intermediate,whereas three (9.37%) were susceptible. the bw/sh derivatives also demonstrated complete resistance/ immune to intermediate reactions viz.,51 (85%) were immune,5 (8.33%) were resistant while 4 (6.66%) were intermediate. adult plant resistance (apr) evaluated at the hill off-station summer site in kaghan was 100% in shws (32/32) and 80% (48/60) in bw/sh derivatives. several genotypes provided resistance at both plant stages viz.,20 (62.5%) shws and 45 (75%) bw/sh derivatives. all the entries were checked for the presence of pm4b,pm9,pm16 and pm30 resistance genes using linked ssr markers. the marker xgwm382.2a flanked the gene pm4b in one sh and 5 bw/sh derivatives. pm9 gene was identified using two markers viz.,xgwm4.4a detected pm9 in one sh and 27 bw/sh while xgwm332.7a detected same gene in one sh and 13 bw/sh derivatives. pm16 and pm30 genes were present in one sh entry and in 2 bw/sh derivatives,detected by xgwm159.5b. the findings revealed that 37.5% (12 entries) of the shs and 5% (3) of the 60 bw/sh derivatives possessed apr. these observations add strength to exploit both intraspecific and interspecific strategies for allelic enrichment within wheat pre-breeding / breeding programs. © 2017,pakistan botanical society. all rights reserved.