Object of research: regularities of productivity traits manifestation, oil content, pollen formation and morphotype in lines, their combination ability, and level of heterosis effect during hybridization. Purpose of the study: to determine the features of pollen formation, self-fertilization, the combination ability of sunflower lines valuable in terms of selection and on this base to create a collection of source material for heterosis selection with a high level of pollen formation and self-fertilization. Research methods: general scientific, field, laboratory, mathematical and statistical ones. The novelty lies in the fact that for the first time in the eastern part of the Forest-Steppe of Ukraine a detailed analysis and evaluation of the pollen fertility restoration lines, sterility-fixing lines of the parent components and first-generation sunflower hybrids were carried out in terms of pollen productivity. The necessity to evaluate the pollen formation ability of inbreeding lines while selecting the pairs for cross-breeding in order to obtain the high-yielding sunflower hybrids has been proved. The influence of pollen productivity of the pollinator on the seed-setting rate of the plants of the sterile analogue in cross-breeding was established. The variability of the total combination ability (TCA) and the specific combination ability (SCA) of the fertility restoration lines with various pollen formation ability was determined. The interrelation of the pollen formation traits, self-fertilization, viability and heat resistance of the pollen and their influence on the combination ability of the fertility restoration lines is established. The methodic recommendations for the evaluation of sunflower lines regarding the heat resistance, seed-setting rate, pollen formation and combination ability have been further developed; a collection of lines regarding a set of valuable features has been created. The results: during 20112019 on the basis of the conducted researches the following lines for creation of the sunflower hybrids had been chosen: Kh06112V, 752-07, 07-3, 733-07, 07-14, Kh526V, Kh144V, Kh134V, Kh135V. They are the donors as for the number of flowers in the head, the percentage of seed-setting rate, the weight of seeds from the head, self-fertilization, viability and heat resistance, and the high rates of TCA and SCA. The following best hybrid combinations according to the amount of pollen in the main head have been chosen: line 752-07 with the tester Skh1010А/Мkh53-10B – 11,234 million pieces, with the tester Skh808А/ Kh1002B – 8,665 million pieces; line Kh06112V with the tester Skh1010А – 9,33 million pieces; with the tester Skh808А / Kh1002B – 7,92 million pieces; line 07-17 with the Skh1010A tester – 23,22 million pieces; line 07-03 with the tester Skh1010A – 13,26 million pieces, line 07-42 with the tester Skh808A/Kh1002B – 11,45 million pieces, and line Kh135V; they had a dominant effect on the level of this trait in F1 hybrids; a high degree of TCA effect indicates it. The sterile analogue Skh808A/Kh1002B, which has the greatest and stable effect of SCA (the value of SCA constant was equal to 296.71), has been chosen; so, it can be recommended as a tester with a broad genetic basis for creating the three-line sunflower hybrids resistant to the high ambient temperatures. Degree of implementation. The following collection of sunflower lines was created on the basis of the established features of the pollen formation, viability, heat resistance, self-fertilization and combination ability: 07-13, 738-07, Kh06118V, Kh526V, Kh397V, 07-20, Kh135V, 752-07, Kh144V, Kh134V, Kh06112V, 07-3, 733-07; they are used in the selection program of scientific research “Oil-producing crops. Sunflower” of the Plant Growing Institute named after V.Ya. Yuriev of the National Academy of Agrarian Sciences of Ukraine. The methodical provisions regarding the evaluation of sunflower line material influence on the pollen formation ability, heat resistance, self-fertilization, and combination ability in a complex with the economically valuable traits are used in the educational process during training the applicants for the educational level “Bachelor” and “Master” in specialty 201 “Agronomy” (06.01.05 – selection and seed growing).
Scope of implementation: scientific institutions of NAAS, scientific and research, selection and seed growing institutions of the National Academy of Sciences and Ministry of Agrarian Policy of Ukraine, as well as educational establishments.
