Prospect for Incorporation of Ppd-D1a Allele in Russian Spring Bread Wheat Cultivars.

Varieties of spring bread wheat with the Ppd-D1a allele are insensitive to the photoperiod and are widespread in the world. The overwhelming majority of spring bread wheat cultivars in Russia are sensitive to the length of daylight. Incorporation of the Ppd-D1a allele in Russian cultivars of spring soft wheat will make it possible to accelerate breeding, using one to two additional vegetations per year. The aims of this paper are to (1) consider a trend of distribution of the Ppd-D1a allele among spring bread wheat of the Northern Hemisphere, (2) reveal an influence of the Ppd-D1a allele on agronomic traits of spring bread wheat, and (3) designate the main ways of breeding work for creation of Russian spring bread wheat with insensitivity to the photoperiod. The frequency of the Ppd-D1a allele increases from countries at high latitude to those at low latitude. The influence of the Ppd-D1a allele on agronomic traits depends on the geographic latitude where the experiment takes place and leads to a reduction of the period from seedling to heading, plant height, spikelets per spike, and protein content and to an increase in duration of green leaves after heading. The Ppd-D1a allele has a negative effect on wheat yield north of 50° N. The high frequency of the Ppd-D1a allele in Canadian spring bread wheat varieties indicates that this allele can become widespread in some regions of Russia. The negative effects caused by this allele can be compensated by reasonable selection of parents for hybridization. [ABSTRACT FROM AUTHOR]