Exploitation of Novel Protocol for R-gene Transfer in Common Bread Wheat (Triticum aestivum L.)

Bread wheat (Triticum aestivum L.) is the second most important staple crop suffering from various fungal, bacterial and viral diseases leading to a decrease in yield and productivity of the crop. Breeders have found r gene responsible for developing resistance in the crop against these pathogens. This review attempts to describe the transfer of alien resistant gene (r gene) in wheat and also the techniques involved in it. R gene is covered in details with gene for gene hypothesis and the five classes of r gene. Different approaches both traditional ones, such as backcross, pedigree, and recurrent selection have been discussed, as well as modern ones like mutation breeding, somaclonal variation, and genetic engineering, which address both genetic gain and genetic loss. The transfer of r gene for resistance to specifically powdery mildew (caused by Erysiphe graminis), karnal bunt (caused by Tilletia indica) and rust (Leaf rust, Puccinia triticina; Stem rust, Puccinia graminis: Strip rust, Puccinia striiformis) are outlined. Finally, we made an effort to discuss about possible future advances in R-gene transfer.