Environmental plasticity of alfalfa collection accessions in terms of fodder and seed produc-tivities on increased soil acidity

Abstract

Introduction. Enhancement in the adaptive response of alfalfa starting breeding material to the growing conditions is important and allows us to maximally fulfill the potential fodder and seed productivities of intensive varieties.

The aim and tasks of the study. The research objective was to evaluate the environmental plasticity of alfalfa collection accessions in terms of fodder and seed productivities on increased acidity in different years of grass stand use.

Materials and methods. The investigation was carried out in the fields of the Institute of Fodder and Agriculture of Podillia of NAAS in 2012–2016. 92 purple and hybridalfalfa collection accessions of different eco-geographical origin were taken as study material. The methods: field (phenological observations and records), laboratory (records of seed productivity), mathematical and statistical (objective assessment of experimental data).

Results and discussion. The coefficient of environmental plasticity (bi) > 1 was recorded for 53 collection accessions, but the productivity level by dry matter output was significantly lower than that in the standard variety ‘Syniukha’. Such accessions potentially better respond to the growing conditions, and they can be used in breeding to create intensive varieties by this trait. Over the study period, the fodder productivity close to that the standard variety was only found in accessions ‘Cordoba’ (UJ0700617) and ‘Oahasa’ (UJ0700371), in which the dry matter output was 1.35 and 1.31 kg/m², respectively. Low values (0–0.67) of the stability variance (Si²) indicate that the obtained empirical values do not substantially differ from the theoretical ones.

For the seed productivity, the regression coefficient b_i oriented to accessions with the greatest response to the growing conditions (b_i>1) was recorded in 44 accessions; 4 of them were at the level of the standard variety ‘Syniukha’ by seed yield: ‘Palava’ (UJ0700622), ‘Sevani-1’ (UJ0700189), ‘Kisvardai’ (UJ0700190), ‘JJ Paso’ (UJ0700364) – 49.88–53.8 g/m² with the standard value of 52.08 g/m². The stability variance value (Si²) ranged rather widely – from 1.77 to 2190.6.

Conclusions. Evaluation of the environmental plasticity of alfalfa collection accessions on increased soil acidity identified several accessions with positive responses to improved growing conditions and  fodder and seed productivities that were sustainably high for 4 years. They are ‘Palava ‘(UJ0700622), ‘Sevani-1’ (UJ0700189), ‘Kisvardai’ (UJ0700190), and ‘JJ Paso’ (UJ0700364), which can be used as starting material to breed intensive varieties by the above-mentioned traits. The environmental plasticity coefficients of (b_i) for the fodder and seed productivities ranged within 0.49–1.09 and 0.94–2.02, respectively; the stability variances (Si²) – within 0.01–0.07 and 214.96–937.32, respectively