ผลของความร้อนต่อการตอบสนองทางสรีรวิทยาและความเครียดออกซิเดชันในข้าว (Oryza sativa L.)

Abstract

High global temperature is a serious concern nowadays. It widely causes multiple issues, especially adversely affects agricultural crops including rice, a staple and economically important crop of Thailand. However, information regarding effects of heat stress on rice is still scarce. This research, therefore, aimed to demonstrate the responses of rice to heat stress. Rice cultivar KDML 105 was selected for the study. For the experiment, 30-day old seedlings were treated with three different temperature schemes, i.e. 30/25°C (control), 35/30°C and 40/35°C for 5 days and recovered for 10 days under the control condition. The results showed that growth parameters including fresh weight, dry weight and root length of rice seedlings under 40/35°C treatment tended to be higher than those under the control and 35/30°C treatments but not significantly different. Photosynthetic rate, stomatal conductance and hydrogen peroxide significantly increased during the treated period, especially in 40/35°C treatment, then dropped dramatically during recovery time while proline noticeably increased at recovery time of 40/35°C treatment. The treatment of 35/30°C showed the same trend as control. On the other hand, leaf greenness, relative water content and peroxidase showed no significant difference among treatments.