Study of Ppd-D1 gene impact on different phenotypic traits in wheat (Triticum aestivum L.)

Wheat is world’s most widely cultivated food crop after rice which belongs to the family Graminae (Poaceae) and the genus Triticum. Presence and level of expression of Ppd genes in winter wheat and spring wheat varieties can be photoperiod sensitive or insensitive. The photoperiod insensitive wheat varieties are early to flowering in short days condition as compared to their counterpart photoperiod sensitive varieties. Photoperiod sensitivity is controlled by Ppd-A1, Ppd-B1 and Ppd-D1 genes of group 2 chromosomes. Ppd-D1 gene has been identified as the major source of earliness in wheat varieties worldwide. All the 242 lines of wheat were genotyped with Ppd-D1 marker and observed 1:1 segregation among the population for the presence and absence of this gene. It was observed that presence of this gene reduced 11 traits as compared with those lines which had no Ppd-D1 gene but few traits were expressed positively by the presence of this gene. Reduction in days to heading and plant height is the common effect observed by many researchers and days to heading also affect the spot blotch severity as reflected by area under disease in this experiment. Diversity in climate is attribute of India and variability created by Ppd-D1 gene for flowering time may be exploited in breeding programme for development of varieties for divergent regions.