Study of rice resistance to water deficiency

Abstract

Abstract. Of the various abiotic stresses, the most important limitation of rice production in many countries is drought or water scarcity. The aim of the study is to study collection, hybrid and breeding varieties and samples of rice for tolerance to prolonged soil and air drought, to select drought-resistant forms for breeding new varieties. Methods. The objects of research – 68 varieties and samples of dry land rice were cultivated in irrigated and flooded areas (Proletarsk, Rostov region) in three repetitions. Plot area – 10 m2, seeding rate – 500 seeds/m2. Irrigation was carried out by the release of water from the irrigation canal after sowing on May 10 with a layer of 10 cm and during the growth period with complete drying of the soil surface. The degree of drought resistance was determined by the ratio of the value of the trait in the test to that in the control (T/C). Scientific novelty. The different degrees of drought resistance of rice samples were determined by the ratio of grain productivity under conditions of water deficit and sufficient water supply, new regularities were revealed. Results. It was found that varieties and samples during drought and flooding formed different grain yields, which, with a moisture deficit, averaged 63.7 % of the norm. The correlation between the yield during drought and the yield upon flooding was weak positive (r = 0.23 ± 0.01), with their T/C ratio – average positive (r = 0.59 ± 0.01), and the relationship between the yield upon flooding and drought resistance – medium negative (r = –0.64 ± 0.01). 10 cultivars and samples with a degree of drought tolerance of more than 75 % were identified, such as An-Yun-Ho, Chan-Chun’-Man, Zolotye vskhody, Malovodorebovatelnyy, ZULK 2, ZULK 6, in which the ratio of yield under dry and normal conditions ranged from 77, 9 to 91.6 %. The maximum yield in drought conditions was formed by a new selection variety of the ARC “Donskoy” Argamak – 6.10 t/ha and selection samples: 7970 (Komandor × Chan-Chun’-Man) – 5.24 t/ha, ZULK 8 – 4.90 t/ha.