The morphological and physiological studies Gorontalo local upland rice treated with drought and shade stresses

Abstract

Abstract Crop growth and production are strongly affected by abiotic and biotic stresses. Survival rate frequently been used to evaluate rice drought tolerance with a low survival rate of rice plants undergoing drought stress leading to low yields. The aim of this research was to obtain Gorontalo local upland rice variants that are tolerant against drought and shade stresses by considering the morphological and physiological characteristics. The research was conducted in Bulotada Barat Village, Sipatana District, Gorontalo, from January to August 2017. Employing the randomized block design with three replications, the research consisted of two treatment factors. The first factor is the accession, which consists of two tolerant accessions; two moderately tolerant accessions, two drought-sensitive accessions, and two shade-sensitive accessions. The second factor pertains to the drought and shade stresses which consist of drought + 25% shade stress, drought + 50% shade stress, and a control. Irrigation in the drought control specimen was given until inundation reached 1.5 cm. In a drought-stressed situation, irrigation was given when the groundwater reached -30 to -35.9 kPa. The Ponda Merah accessions were the accessions that were tolerant against drought and shade stresses. The morphological characteristics of Gorontalo local upland rice that showed tolerance against drought and shade stresses were longer roots (33.20 cm), heavier dry weight (38.82 gr), a thinner leaf (186,56 cm2.g-1), and a higher yield (4,90 gr.cluster−1). The physiological characteristic of the Gorontalo local upland rice that showed tolerance against drought and shade stresses was the sugar content (0,73 g.g-1) which was higher than the other treatment.