Assessment of the combinational ability of inbred winter rye lines in plant height

The aim of the research is to evaluate the general and specific combinational ability of inbred winter rye lines in plant height and identify relatively short-stemmed combinations. The starting material for the crossing was 22 homozygous rye lines carrying sterile cytoplasm of the Pampa type. The male fertile homozygous lines mf H-1423, mf H-1247, m fH-732 and mf H-842 were used as testers, in which the plant height was 122 cm, 120 cm, 102 cm and 100 cm, respectively. Test crosses were carried out in isolated plots according to the topcross scheme. A total of 88 simple F1 hybrids were produced. They were tested on plots of 8.0 m2 in 3 repetitions. The average height of plants in F1 hybrids was 129 cm and ranged from 114 cm to 145 cm. The hybrids with the participation of the mf H-732 and mf H-842 tester turned out to be the shortest-stemmed, and the tallest ones with the participation of the mf H-1423 tester. Both general (GCA) and specific (SCA) combinational abilities made a significant contribution to the variance of the plant height trait. The genotypes ms H-422 and ms H-1179 had a significantly higher GCA compared to other lines, and ms H-700 and ms H-1058 had a lower one. Among the testers, the high-stemmed mf H-1423 and mf H-1247 lines had a reliably high GCA, and the short-stemmed mf H-732 and mf H-842 testers had a reliably low GCA. Combinations involving short-stemmed testers made up a group of the shortest-stemmed hybrids, in which plant height varied from 114 to 120 cm. It is shown that lines with low effects are of great value for practical breeding not only for GCA, but also for SCA. The ms H-700 line is of interest, which simultaneously combines low grades in GCA and SCA.