Effects And Model Of Low Temperature And Poor Irradiation Stress On Growth And Quality Of Fruits Of Greenhouse Tomato

In order to study the effects of low temperature and poor irradiation on tomato,a tomato cultivar 'JinFen5' was selected as experimental material, four levels of low temperature and two levels of poor irradiation were installed in a climatic chamber to study their effects on tomato growth and development. And three models were chosen to simulate the tomato plant growth period, growth index and dry matter production and distribution after low temperature and poor irradiation stress, which include product of thermal effectiveness and PAR (TEP), light and temperature effect(LTF) and physiological development Time (PDT), and the independent test data were used to validate these models. The results of the study are as follows:(1) Low temperature and poor irradiation delayed tomato plants flowering period, fruit period and maturing period of time. The greatest influence on tomato plants was T1L2 processing which lasted for 10d, the flowering stage, fruit setting stage and maturing stage were delayed 14d, 22d and 29d respectively.(2) The low temperature and poor irradiation stress made tomato plant height,stem diameter and leaf area reduced to different extent compared with CK. Indicators of tomato after stressing were processing along with growth days like the "S" type.And low temperature and poor irradiation last more than 8d then the tomato plant growth index during the observation period are unable to return to CK levels, and the time for tomato growth index to the fast growing period all had different degrees of backwards.(3) The low temperature and poor irradiation composite stress seriously affected the tomato plant dry matter accumulation per plant. The end of the processing tomato plant dry matter weight increased with the increase of growth time, but its dry matter cumulant was significantly lower than that of CK. After stressing the tomato plant leaf dry matter distribution ratio was higher than CK, dry matter to leaf ratio decreased along with low temperature stress decrease, at the time to the fruit of dry matter distribution with the stress had delayed,stem ratio at the end of the stress had a first rise again downward trend.(4) organic acid content of tomato fruit was significantly higher than CK after low temperature and poor irradiation stress, and increased along with the stress degree increased. As well tomato vitamin C, soluble solid and lycopene content were decreased after low temperature and poor irradiation, meanwhile the index as a whole were increased in the same PAR with temperature rise.(5) Three models of TPE, LTF and PDT were used to simulate indicators of tomato after low temperature and poor irradiation, the results showed that PDT method in simulation of flowering period and fruit setting had highest accuracy, and TEP method was the optimal simulation of maturing stage. To the plant leaf area and dry matter production simulation, the TEP method was the best. As well as tomato plant height a, the highest model precision was LTF method.