Assessment of combinational ability of inbred lines of winter rye by the topcross method

Abstract

Dentification perspective on combinational ability of the inbred lines of winter rye is an important stage in hybrid breeding. The purpose of researches - to estimate the general and specific combinational ability of the inbred lines of winter rye by a method of full top crossings. As a maternal form 30 homozygous lines of rye bearing sterile cytoplasm Pampas type served. As testers 4 male fertile homozygous lines used : mfН-1432, mfН-1423, mfН-1147 and mfН-1842. Test crossings carried out in 2019 on spatially the isolated plots. In total 120 simple interlinear hybrids of F1 were received. Their test carried out in 2020 on plots 8,0 m2 in 2 repetitions at norm of seeding of 500 grains on 1 m2. As the standard used population variety Valdai. Productivity of hybrids F1 varied from 5,08 to 7,55 t/hectare at average productivity in experience 6,27t/hectare. Hybrids with participation of the line msH-1185-1 were the most yielding. Their productivity varied from 6,92 to 7,48 t/hectare depending on a tester. Frequency of hybrids of F1 with authentically high competitive heterosis made 20 of 120 or 16,7 %. In dispersion of a sign of productivity the essential contribution was made both the general (GCA), and specific (SCA) combinational ability. However fell to the share of effects GCA 91,2 % of all dispersion of productivity, and to SCA share - 6,9 %. The high relation variances by GCA/SCA is pointed to rather high genetic divergence by the inbred lines taken for crossing. Authentically high GCA showed 7 sterile lines: ms H-1185-1, msH-1185-2, msН-1179, msН-1238, msН-700, msН-48, msН-1247. Among lines testers of the best on GCA there was mfН-1147. High effects of SCA showed the msН-451, msН-577, msН-842, msH-1185-2 and msН-1190 lines, and also testers of mfН-1432 and mfН-1423. It is characteristic that average productivity of hybrids with participation of lines with high GCA was authentically above, than average productivity of hybrids with participation of lines from high SCA (6,76 t/hectare against 6,24 t/hectare, tfact=3,38> t05=2,22). Significantly low GCA possessed 9 sterile lines. Positive correlation between effects of GCA lines and level of their own productivity is revealed (r=0,59, t fact =2,30> t 05=2,22)