Identification of gene action on rice tolerance to low temperature stress

The development of low temperature tolerant rice varieties is needed to increase national rice productivity. Crosses and selection are the stages of the activity of developing low temperature tolerant plants. The effectiveness of selection depends very much on the action of the genes that control the selection character. Epistatic gene action will inhibit the progress of selection on self-pollinating crops such as rice. The purpose of this study was to estimate the gene action of the character of rice growth at low temperature stresses, and predict whether the growth character was controlled by the action of additive genes or by the action of epistasis genes. The research was conducted from July 2017-March 2018 at Brastagi Experimental Farm, Karo District, altitude 1340 meters above sea level with average temperature of 19 °C. The genetic material used was 191 F2 plants from the crossing of Situbagendit x Red Sigambiri and each 10 parents. The results showed that the character of plant height, panicle exsertion, age of flowering, and production had a middle value that varied with heritability values from low to high. The action of duplicate epistasis additive genes occurs in the character of generative phase plant height and flowering age while the character of plant height in germination phase, panicle exsertion and production is governed by the action of complementary epistasis genes. The characters observed have a pattern of distribution that is continuous and controlled by many genes.