Study on Cold Tolerance of Rice at Different Altitudes

Using ecological differences at different altitudes in Yuanyang Terrace Yunnan, the traditional varieties (Yuelianggu and Hongjiaolaojing) and the modern varieties (Chujing27 and Hexi22) as materials were used to study cold resistance of rice. The results showed that: (1) Different varieties of SOD activity all reached the highest value at 1 850 m.(2) The POD activity of Hongjiaolaojing reached highest value when at 1 850 m altitude while the modern varieties respectively reached highest values at the lowest and middle altitude. (3) The CAT activity of traditional varieties reached the highest value at 1 850 m, while the CAT activity of modern varieties reached the highest value at 1 650 m. (4) In addition to Chujing27 was the highest content of MDA at 1 450 m, other varieties had reached the highest value at 1 850 m.(5) In addition to Hexi22 was the highest content of soluble protein at 1 650 m, other varieties had reached the highest value at 1 850 m.(6) The soluble sugar of Hongjiaolaojing and Chujing27 all reached highest value at 1 850 m. The soluble sugar of Yuelianggu and Hexi22 all reached highest value at 1 650 m. In conclusion, we can see that the growth environment of high altitude can bring oxydic damage to the traditional varieties and modern varieties inordinately. But the change rules of different varieties resistant to cold index are not consistent.