HYBRID VIGOUR EFFECT IN SORGHUM SELECTION

The authors see application of hybrid vigour in the hybrids obtained on the basis of mother lines with cytoplasmic male sterility as a promising way of sorghum selection. The selection is aimed at increasing sorghum productivity. Hybrid vigour is observed in the first generation of hybrids which was caused by interaction among genes (dominance and epistasis) and additive effect of dominant genes. Its effect is weakened in further generations. The paper explores the effect of heterosis of F1 hybrids obtained on the basis of CMC lines with A1, A2, A3, A4, M-35-1A, 9E types of sterility and productive pollinator varieties which are resistant to biotic and abiotic factors in the region. The experiment was carried out on the pilot plots of Research and Technological Institute of Sorghum and Corn “Rossorgo” in 2015-2016. The area of the plot was7.7 m2; frequency observed was three times; landfill location was random. The density of new hybrids, standards and parental forms was 100 thousand plants pro a hectare. The frequency of pure (superior to the superior parental form), hypothetical (superior to the average value of parental forms) and competitive (excess of the sign of hybrid F1 over the released hybrid) heterosis in terms of: plant height, inflorescence length, grain mass per panicle and 1000 grains, yield. Heterosis was more frequent in terms of plant height, inflorescence length, weight of 1000 grains, and less frequently (mainly in 2016) in terms of yield and weight of grain from a panicle. The authors indicate the prospective combinations of crosses with low effect of competitive heterosis in plant height and the highest yield as: A1 O-Yang 1/Avance, A1 O-Yang 1/Topaz, A3 Feterita 14/Mercury, A4 KP 70/Volzhskoe 4. These hybrids form the grain yield of 4.09-9.15 t/ha (2015-2016) and are characterized by the effect of competitive heterosis in2016 interms of grain yield from 2.1 to 71.4%. Hybrids A1 O-Yang 1/Volzhskoe 4 and A2 KVV 114/Avance differ in competitive heterosis by weight of 1000 grains (51.7-60.0%) and grains from one panicle (5.8-52.9%). The hybrids outlined are expected to be relevant for further tests.