Variability and inheritance pattern of 1000 grains mass in corn hybrids in diallelic crosses

The results of studying F1 corn hybrids based on the “weight of 1000 grains” trait, bred by the diallelic method (method 2 model 1), are analyzed. The experimental part was carried out in 2017–2018. The experimental plots were located in LLC VPO Pokrovskoye, Engels district, Saratov region. 11 self-pollinated lines of corn were used as the starting material for producing hybrids. It was established that a high effect of general combining ability and dispersion of specific combining ability according to the trait “weight of 1000 grains” were determined in the line SPK 20 in 2017 and line SPK 18 in 2018. High dispersion of specific combining ability in corn hybrids in 2017 was detected in 25 hybrids from 55 and in 2018 for 12 hybrids. The ranks of self-pollinated lines according to the magnitude of the ACS effects are located in the sequence SPK 16>SPK 17>SPK 13>SPK 20>SPK 18>SPK 15>SPK 21>SPK 13>SPK 22>SPK 19, and the SCS dispersions are SPK 20>SPK 18> SPK 17>SPK 16>SPK 12>SPK 15>SPK 21>SPK 13>SPK 22>SPK 19>SPK 14. A close correlation has been established between the SCS effect and true and hypothetical heterosis (0.67 and 0.82 – in 2017; 0.71 and 0.87 in 2018), as well as between true and hypothetical heterosis (0.85 in 2017 and 0.86 in 2018). Also significant are the correlation coefficients between the mass of 1000 grains and the specific combining ability effect (0.59 in 2017 and 0.41 in 2018); between the weight of 1000 grains and true heterosis (0.33 – 2017 and 0.35 – 2018); between the weight of 1000 grains and hypothetical heterosis (0.42 - 2017 and 0.50 - 2018). The adequacy of the additive-dominant model is considered by excluding from the calculation the lines SPK 12 and SPK 16 in 2017 and the line SPK 16 in 2018 with epistatic interaction of genes. Under the conditions of 2017, the inheritance of the trait “weight of 1000 grains” is controlled by overdominance, and in 2018, complete dominance is manifested.