Estimation of drought resistance of rice samples on an osmotic sucrose solution

Abstract

Drought is a significant abiotic stress factor for agricultural crops, including rice, as freshwater shortage is increasing in the world. The current paper has presented the results of laboratory trials to study the effect of solutions with high osmotic pressure on the ability of seeds to germinate and on the growth of rice sprouts. The purpose of the study was to estimate rice varieties and samples for drought resistance at the initial stages of ontogenesis using osmotic agents. The objects of the study were 67 rice varieties and samples from the VIR, the FRC of Rice and the ARC “Donskoy”. Seeds were germinated in a thermostat on filter paper in Petri dishes in 8, 12, and 16 atm sucrose solutions. As a result of the study, there was found that the best option was rice seeds’ germination in a sucrose solution of 8 atmospheres, in which the samples varied significantly in germination, length of sprouts and roots, both in the trial and in the control. Seed germination on the control was 96.6 %, and in the trial, it significantly decreased to 60.9 %, varying from 20 to 100 %. There were 50.8 % of samples with germination from 60–80 %. At the same time, 4.5 % of the samples were isolated with a germination rate of more than 80 % in the trial. In the trial, a sprout length among the samples varied from 0.2 to 1.4 cm. There were identified 13.5 % of the samples, which had a sprout length more than 1 cm. According to the ratio of a sprout length in the trial to the control, the samples were distributed asymmetri­cally, there were more samples with a low ratio, however, there were identified 4.5% of samples with a maximum O/K ratio (35–40 %). In the trial, aroot length ranged from 0.1 to 4 cm. The frequency distribution was asymmetric, there were 61.2 % samples with a very short root, up to 1 cm. The O/K ratio according to a root was right-sided asymmetric, 74.6 % of the samples had a low ratio from 0 to 15%. There were identified 3 % of samples with the ratio of more than 50 %. They were No. 39 (ZULK 1) and No. 50 (ZULK 12). These samples are used in the breeding process to develop drought-tolerant rice varieties.