INSTITUTO TECNOLOGICO DE CHASCOMUS
Unidad Ejecutora - UE
congresos y reuniones científicas
Study of rice tolerance at suboptimal temperatures in a panel with broad genetic diversity
RODRIGUEZ ANDRÉS; CHECOVICH MARIANA LEONELA
Simposio; FRONTIERS IN BIOSCIENCE 3; 2018
Rice (Oryza sativa L.) is regarded as the most important crop in terms of human nutrition. For rice at the seedling growth stage, The critical range of low average daily temperatures is 12-13°C while the optimum range is 25-30°C. In the south-central rice region of Argentina, the average daily temperature is 16ºC (21/13ºC maximum/minimum) is a stressful condition of suboptimal temperatures (ST) for rice growth. In this sense, the aim of the present work was detect rice cultivars with contrasting performance under ST. For this purpose it was evaluated the physiological response of 407 rice variates (ARS-USDA). Seedlings of each varieties were grown under conditions of optimal temperature (28/24°C day/night). when the third leaf emerged half of the seedlings were transferred to a ST condition (21/13°C day/night). The growth of the third leaf of each plant was determined until ceased. We evaluate different parameters as the time and the rate of elongation, the final length of the leaf, the size cell, the PSII performance, the net photosynthesis rate and the stomatal conductance. The main effect of the ST stress was the reduction of the final length (13 and 69% according to the variety). This effect was attributed to the fall registered in elongation rate under ST and not to the size cell because did not shown difference between treatments. A PCA was performed to determine the relationship between the parameters described above. Also, the accessions were characterized respect of its tolerance to ST in highly susceptible, moderately susceptible or tolerant based on the PCA results. The results of this work will help to design future strategies the obtaining of cultivars that perform better under this stress.