Biological evaluation of awnless bromegrass in different agro-climatic zones of Yakutia

Abstract

The results of biological evaluation of awnless bromegrass varieties in different agroclimatic zones of Yakutia are presented. A total of 143 collection varieties of awnless bromegrass from the genetic collection of VIR, other research institutions and local wild specimen were used in the research. The varieties studied are highly winter-hardy, the breeding specimen numbers to a greater extent. The drought tolerance of the varieties grown in the three zones of Yakutia is evaluated. A close relationship between winter hardiness and drought tolerance (water retention capacity) in awnless bromegrass was established. The correlation coefficient averaged 0.74. The intensity of transpiration in awnless bromegrass cultivars is evaluated. Analysis of the daily dynamics of transpiration revealed that during the initial development phase of generative shoots (emergence into a tube), the minimum intensity of transpiration occurred in the evening and the maximum in the morning and afternoon hours. During the earing and flowering phase, the intensity of transpiration depends on weather conditions. It has been established that high winter hardiness of awnless bromegrass accounts for high hay yield; low water-holding capacity accounts for winter hardiness and maximum hay yield in the conditions of Yakutia's cryolithozone. The correlation coefficients between winter hardiness, drought tolerance parameters and hay yield at different herbage levels averaged –0,85… –0,24. The standard variety of awnless bromegrass Kamalinsky 14 is stable and highly adapted to the conditions of Yakutia, and is recommended as a seed parent in the selection process for awnless bromegrass. When selecting varieties of awnless bromegrass, attention should be paid to varieties from local breeding, as well as populations of expeditionary collections across Yakutia, which have high seed yields.