MOLECULAR AND MORPHOLOGICAL DIVERSITY WITH BIOTIC STRESS RESISTANCES OF HIGH 1000-GRAIN WEIGHT SYNTHETIC HEXAPLOID WHEATS

Abstract

Accumulation of favorable characteristics from the genetic resources of Triticeae and their exploitation for bread wheat improvement has always been the main thrust of wheat breeding programs. Harnessing the genetic diversity for yield contributing characteristics has recently diverted the attention of wheat breeders to utilize synthetic hexaploids (SHs) in their programs where one factor being exploited is the high thousand grain weight diversity present in SHs. This requires generating a wide array of data for economically important descriptors which will ultimately permit the acceptance of the synthetic hexaploids with favorable traits. In the present investigation synthetic hexaploids having higher grain weight are characterized and their genetic diversity elucidated to prove that synthetics with higher 1000-grain weight had different genetic makeup to substantiate the view that utilization of SHs for yield improvement will widen the genetic base of the bred derivatives leading to future varietal development. Of the morphological parameters days to flowering/days to physiological maturity and plant height are important for plant selection and progeny advance. Coupled with 1000 kernel weight diversity with these parameters synthetics have been identified for breeding utilization to cover both irrigated and rainfed (drought) cultivation areas. All the synthetics studied had karnal bunt resistance and 62% possessed resistance to prevailing strains of stripe rust which make them available to improve the yield potential of bread wheat in areas where these two biotic stresses are wheat production constraints. Further the utilization approach of synthetic hexaploids for wheat improvement is also discussed.