Indian Journal of Genetics and Plant Breeding (The)

Breeders have extensively used marker-assisted selection to improve the agronomically superior varieties for disease resistance. Here, the mega wheat variety of India, HD3086, has been improved for leaf rust resistance by transferring a leaf rust resistance gene LrTrk from Triticum turgidum var. durum cv. Trinakria (AABB, 2n = 4X = 28). Taking a tetraploid donor parent instead of a hexaploid produced partial sterility in initial generations, but fertility improved beyond BC₂F₁ generations and aided in the rapid and higher recovery of recurrent parent genomes. Leaf rust resistance gene LrTrk was selected in every backcross generation with the help of resistance gene linked marker Xgwm234 and further confirmed by rust screening. Further, rigorous phenotypic selection of plants with rust resistance gene LrTrk for their phenotypic similarity to recurrent parent HD3086 in backcross generations helped us identify six homozygous NILs in BC₂F₃ generation. All six NILs carried more than 95% of the recurrent parent genome (RPG) when analyzed with polymorphic markers between the parents. The six NILs also showed no difference in the ago-morphological traits compared to RP HD3086. Out of six, one NIL, HD3086+LrTrk-2, was selected with numerically higher yielding than recurrent parent HD3086 and at par performance for all other traits. This NIL will be nominated in AICRP trials before being it to the farmer’s field. The improved NIL will provide an alternative for the susceptible cultivar from the farmer’s field and broaden the genetic base of wheat cultivars grown in India.