Effects Of Low Temperature And Poor Light On Growth And Development Physiological And Biochemistrical Characters Of (Capsicum Frutescens.L) In Solor Greenhouse

With Longjiao No.2 and Jiamusi pepper treated by low temperature and poor light (LTPL)conditions,this study was conducted to determine growth and development,root vigor,photosynthetic rate,superoxide dismutase(SOD)activity,electricity conductivity, content of malondialdehyde(MDA)and Pro of the pepper in the early season of blossom during the recovery growth process so as to understand effects of the LTPL on plant growth and development and photosynthesis of the pepper as well as it's adaptive mechanism to the LTPL.Results showed that the LTPL slowed down plant height and stem diameter enlargement and leaf area growth while plant growth was inhibited by low temperature more than poor light.Root vigor of pepper treated with the LTPL decreased, and after 10 days recovery the vigor for the sub-suitable temperature and poor light (150μmol·m^<sub>-2·S^-1,100μmol·m^-2·s^-1and 23℃/9℃)condition recovered to normal(CK) where no LTPL was added.Under the LTPL(150μmol·m^-2·s^-1,100μmol·m^-2·s^-1and 18℃/5℃)condition,the vigor was still in low,the content for Chla and Chlb and Chl(a +b)in leaves decreased,net photosynthetic rate and transpiration rate and stomatal conductivity and intercellular CO₂ concentration decreased,in contrast,ratio of Chla to Chlb increased.Meanwhile,The LTPL made SOD activity decrease,electricity conductivity increase,and MDA raise.Low temperature had a greater damage on cell membrane compared to poor light,and after10 days recovery the leaves' SOD activity of pepper grown in sub-suitable temperature and poor light(150μmol·m^-2·s^-1, 100μmol·m^-2·s^-1and 23℃/9℃)condition recovered to the normal while it still remained low level under the LTPL.Under intensive light(150μmol·m^-2·s^-1)condition,low temperature benefited to accumulation of Pro content in leaves,Pro amount increased greatly when the LTPL(150μmol·m^-2·s^-1,23℃/9℃,18℃/5℃)was applied,and after 10 days recovery Pro content slowed down but it was still in higher level compared to CK. Whereas,Pro rates of leaves,treated with the LTPL(150μmol·m^-2·s^-1,23℃/9℃,18℃/5℃),was significantly higher than that of CK,and with the LTPL ((100μmol·m^-2·s^-1,18℃/5℃)was still lower than CK.Above results obtained from the LTPL treatments varied with varieties,which,in return,reflecting different adaptive degree of varieties to low temperature and poor light stress.