Adaptivity of selective numbers of spring wheat obatained in crossing different eototypes according to the quantity of spikelets in the main ear
Breeding improvement takes a significant place in increasing and stabilizing the soft winter wheat yield, the main cereal crop in Ukraine. The study of the peculiarities of the implementation of the productivity potential and the identification of mechanisms for the formation of components of productivity of the most important economic values of crops plants in a changing environment is important for establishing the reaction norm and the selection of the most resistablee productive genotypes and their inclusion into breeding programs. The peculiarities of the formation of spikelets number in the main ear in the selection numbers of soft winter wheat, obtained from crossing different ecotypes in contrast to the hydrothermal indices of the research years are revealed. The calculated indicators of plasticity and stability of the number of spikelets in the main ear determine different sides of the complex property - the adaptive potential of the genotype. Proceeding from this, scientists suggest the definition of the average index for a generalized assessment of the adaptability of a specific genotype, which would most fully take into account the values of various parameters. For this purpose, it is suggested to use grouping using parametric statistics, which allows to determine the ranks of individual indicators and to calculate the average rank by their total number. The correlation in the number of spikelets and the elements of the yield structure are studied. A direct correlation between the number of spikelets in the main ear and the grain yields at a significant level (r = 0.560) in 2011 and 2012 and weak one (r = 0.083) in the most unfavorable year of 2013. The direct correlation at the significant level is established between the amount of spikelets in the main ear and the grains number (r = 0.526 - r = 0.648), the weight of the grain from the an ear (r = 0.531 - r = 0.580) and the weight of the the ear (r = 0.523 - r = 0.663) is revealed. The data obtained indicate the importance of the number of spikelets in the formation of the productivity of the soft winter wheat ear and grain yield in conditions of the Forest-Steppe zone of Ukraine. It was established that the genotype factor influenced the formation of the spikelets number in the ear at a level of 55.05 %, and the conditions of the year influenced it a level of 33.81 %. The breeding numbers of soft winter wheat differed significantly in the norm of the reaction to environmental conditions. The coefficient of variation was 7.9 % on the average for the experiment. A slight variation (V = 1.7-5.7 %) was observed in the genotypes of 29 KC, 26 KC, 54 KC, 22 KC. One of the smallest coefficients of variation (V = 5.1 %) was noted in the selection number 54 KC and had the largest number of spikelets in the main ear, in average, for three years. The selection number 54 KC (forest-steppe ecotype / forest-steppe ecotype) ranged the first place in the rating of adaptive varieties by the result of evaluation of the studied breeding numbers in the number of spikelets in the main ear and the plasticity and stability parameters. The number of spikelets in the main ear plays an important role in increasing the productivity of the ear and increasing the grain yield which should be considered when developing a soft winter wheat variety model for the conditions of the Forest-Steppe Zone of Ukraine.