Peculiarities of traits expression of feed and seed productivity of alfalia collection accessions under high soil acidity

Abstract

Aim. To study and assess the environmental adaptability of feed and seed productivity of alfalfa collection accessions under high soil acidity by determining its components - regression coefficient and stability variance. Results and Discussion. Breeding nurseries were established by summer coverless sowing: gutter sowing (row spacing 15cm) - for feed productivity; wide-row sowing (45cm) – for seed productivity. The record plot area was 3 m2, in two replications. To assess the feed productivity, we measured the dry matter yield of four mowings (budding phase); to assess the seed productivity, we determined yield from the first mowing. The environmental plasticity coefficient for the feed productivity (bi) varied across the studied accessions from ̶ 1.24 to 2.33. bi> 1 was found in 16 accessions, but the dry matter yields from most of them were significantly lower than that from the check variety, Syniukha. Low values (0 – 0.34) of the stability variance (Si2) indicate that the obtained empirical values differ little from the theoretical ones. As to the seed productivity, bi> 1 was detected in 16 accessions, 8 of which exceeded the check variety, Syniukha, in terms of seed yield. The stability variance varied in a fairly wide range from 0.12 to 308.93. The obtained values of Si2 confirm the difficulty of alfalfa breeding for increased seed productivity compared to feed productivity, which are often positively affected by opposite hydrothermal conditions: drought positively affects the seed yield, while excessive rainfall boost the feed productivity. Conclusions. Alfalfa accessions with a relatively strong response to the improvement of growing conditions with increased feed and seed productivities were selected; they can be used as starting material in breeding for these traits: Radoslava, Olha, Vavilovka (Rodnychok) (Ukraine); Evrika 1 (RF); Ferax 58 (Canada).