Studies About The Effect Of Low Temperature And Weak Light On Morphology, Physiology And Physiochemitry Of Tomato

In this experiment with tomato cultivars zhongshu NO.4 and zhongza NO.9 as research object, the morphological. Physiological and physiochemical response of tomato to low temperature and weak light in different treat time were studied. In the same time, the adapting mechanism of tomato in low temperature and weak light environment and the relation between low temperature and sub-adapting temperature were studied.The study results showed that in low temperature environment, the whole dry weight of tomato hadn't a significant change and low temperature treatment contribute to the accumulation of the whole dry weight of tomato. The dry weight of tomato can be defined by the equation of linear regression of leaf quality and the ratio of leaf quality. With the temperature decreasing, ch1.a content and chl.b content decreased, ch1. a /b value gradually increased, the vigor of the root system enhanced, the content of MDA and the pro-aa had a trend to increase. The different temperature treatment in daytime and night had little influence on the injury degree of tomato. After being treated in 15℃ (day) /5℃ (night) ,compared with Zhongza NO.9, the dry weight and the vigor of the root system of Zhongshu NO.4 was effeciently higher than contrast, while the MDA content was efficiently lower than contrast.On the other side, poor light can decreased the accumulation of tomato dry weight, and increased chl.a contend chl.b content and chl. a /b value, and enhanced the injury degree of leaf. Treated under low temperature and poor light, the chl. a content and chl. b content fall down, chl. a /b value increased more than contrast. When light intensity is 109 μmol. m-2. s-1 or 43 μmol. m-2. s-1, the treatment temperature 15℃ (day) /10℃ (night) and 15℃ (day) /5℃ (night), the content of chl. a and chl. b dropped sharply. The higher light intensity in low temperature can improve the vigor of the root system, In low temperature environment, the higher the light intensity, the higher the content of MDA and the pro-aa.