Heredity of leaf apparatus features in F2 of soft winter wheat
Authors: Hoptsii V.O. 
Published: March 2021

The aim of the research was to study the heredity nature of flag (first top) and sub-flag (second top) leaves of F2 hybrid populations obtained from the crossbred varieties and lines of soft winter wheat of different morphophysiological types.
The research was conducted in the experimental field of KhNAU named after V.V. Dokuchaiev in 2015 – 2016.
The vegetation period of 2015 – 2016 turned out to be abnormally warm with a lot of precipitation. The amount of precipitation during the wheat vegetation period in 2015 – 2016 was 597,8 mm, which was significantly higher than the long-term average (456,0 mm). Such weather conditions affected the course of vernalization and wintering of plants, contributed to the development of diseases and pests, complicated and stretched the harvest period, its quantity and quality.
14 F2 hybrid populations, obtained by crossbreeding 16 varieties and lines were used as a starting material.
The selection of the parent pairs was performed on a set of the morphological and anatomical productivity features. Based on cluster analysis (K-average method), the set of the studied genotypes of soft winter wheat was divided into four clusters. The genotypes of the first cluster had a high level of ear productivity and the maximum level of development of the anatomical structure features of the stem and ear. The genotypes of the second and third clusters are two “opposite” types of variability of the productivity features, leaf apparatus and anatomical structure of the stem and ear. Thus, the genotypes of the second cluster are characterized by a relatively high level of development of the features of ear productivity, but minimal – the features of anatomical structure, and for the third vice versa. The genotypes of the third cluster can be a donor of the anatomical structure features, and the second – ear productivity. The genotypes of the fourth cluster had the maximum level of development of the group of the features of the leaf apparatus, productivity and a fairly high level of the development of the anatomical structure features.
The varieties from the first cluster were used for crossing: Smuhlianka, Izolda, Prestizh, Kharkivska 105; from the second one: Odeska 267, Venera, Ebi, Statna, Dobirna, KIU line – 7; from the third one: KIU lines – 40, L 80 – III / 7, Patriot variety; from the fourth one: Pereiaslavka, Lehenda, line L 89 – I/2.
The hybrids were sown in a block with the parental forms, the area of the plot for the parental forms made up 1 m2, the area of the hybrid populations plots depended on the number of seeds and was equal to 1 – 2 m2.
The level of heredity according to the characteristics of the leaf apparatus of F2 hybrids of soft winter wheat was determined, namely the frequency (Tf) and the degree of transgressions (Td) and the heredity coefficient in the “broad sense”. The frequency of transgressions of the hybrids on the basis of the area of the flag leaf varied from 3,00% to 40,00%, and the degree of transgressions varied from 3,30% to 52,90%, but in three combinations the transgression was zero. The heredity coefficient in the “broad sense” ranged from 0,07 to 0,99. According to the total area of the two upper leaves (flag and sub-flag), the frequency of transgressions varied from 6,70% to 50,00%, and the degree of transgressions – from 3,60% to 45,20%. In two combinations, the transgression was zero. High and medium heredity coefficients, exceeding 0,50, and a high manifestation of transgressions were observed in the combinations: KIU-7 / Smuhlianka (Tf – 33,3 and Td – 45,2%), Kharkivska 105 / Smuhlianka (Tf – 30,00 and Td – 45,23%) Izolda / Prestige (Tf – 30,00 and Td– 12,60%), Ebi / L 89 – I / 2 (Tf – 23,30 and Td – 31,50%). These combinations can predict the effective plant selection, starting with F2 and F3.
Key words: soft winter wheat, F2 hybrids, heredity coefficient in the “broad sense”, frequency and degree of transgression.