Plant Varieties Studying and Protection (May 2013)
Gnome 2 as a donor for winter rye (Secale cereale L.) short stem
Abstract
A stabilizing (directed) selection has created a donor of short stem for winter rye (Secale cereale L.), plant height of which ranged from 50 to 60 cm. The plant height kept symmetry of its distribution curve and the frequency accumulation in central classes (positive excess). For the first time a symbolic designation to new short-stem related Hl-2Hl-2 allele and the donor name (Gnome 2) were proposed. 28 years of stabilizing selection showed that 57% of overall genetic variability of plant height resulted from adaptive genes available for directed selection by phenotype, and 43% from dominant and epistatic factors that predetermines the expression heterosis effect. Gnome 2 donor proved to have genetic additive correlation between the pants height and number of flows per ear, ear length, weight of seeds per plant , 100 seeds weight per plant; to have reverse correlation with ear density seeds weight per ear. The height of original parent components have displayed direct additive correlation with number of flowers per ear and reverse with the ear density. The additive correlation component directly exposes «genuine» impact of parental plants on the expression of the characteristics indicated among the offspring Productive bushing of parental plants, seed weight per plant directly, and seed size (100 seeds weight) indirectly, respectively, influence the height of offspring pants. The reverse additive correlation between the parents height and 100 seeds weight in the offspring is caused by pleiotropic effect of the genes impact thus enabling to combine the desirable characteristics in one genotype. Productive bushing is by 54% due to the impact of general genetic factors among the above, in particular, 30% due to that additive, 24 due to non-additive factors. The concept of genetic improvements for productive bushing of the Gnome 2 rye implies utilization of additive effect through the directed selection, as well as application of breeding techniques for controlling the effect of heterosis caused by the genes of dominant and epistatic impact. The selection paradigm requires simultaneous genotypes selection with immediate examination of the selection results by offspring while in parallel to develop inbred lines, combining these afterwards evaluating general and specific combining ability by productive bushing. It is also to be noted that the productive bushing essentially depends on the environmental conditions, which significantly corrects the implementation of productivity potent, thereby the issue of agronomical conditions aimed at extending the expression of characteristic in question remains.
Keywords