Studies On The Physiological Mechanism Of High Yield Of Grafted Cucumber (Cucumis Sativus L.) In Solar Greenhouse

Studies on the physiological mechanism of high yield of grafted cucumber in solar greenhouseZhang YanpengCucumber cultivars of Xintaimici as scions were grafted on figleaf gourd(Cucumis sativus L). The physiological mechanism of high yield of grafted cucumber in solar greenhouse was studied .The main results were as follows:1.The grafted cucumber had vigorous growth power:the results showed that the plant height of grafted ones were higher, leaf area of grafted ones were larger and ratio of the third length and stem diameter ones was higher than that of own root cucumber .The fruit setting of grafted cucumber were excellant and grafted cucumber had a higher yield than own root cucumber.2. The leaves of grafted cucumber had a higher apparent quantum yield and carboxylation efficiency during the development and grafted cucumber had a higher utilization efficiency of CO2 and light than own root cucumber. This experiment also indicated that: the low temperature and the low light density has interaction effect in suitable temperature, the photosynthesis of grafted cucumber does not decline apparently as a result of low light density, but at low temperature the grafted and own root cucumber have a low photosynthetic rate. The photosynthetic rate of grafted cucumber in greenhouse in winter have an apparent higher photosynthesis rate, and in the late stage of cucumber in spring for high temperature conditions. The aspiration enhances, the photosynthesis rate declined, but the grafted cucumbers still have a higher photosynthesis rate.3.The grafted cucumber had a significantly higher vigorous root activity and higher content of chlorophyll and soluble protein, this also indicated that the grafted cucumber had a higher improvement of physiological character and this is the basement of grafted cucumber acquired high yield. 4. The grafted cucumber had a higher SOD,CAT and POD activity and lower MDA content than the own root cucumber during the development. This indicated further the leaves of grafted cucumber have a stronger capability to offence the oxidation of lipid and also showed that the membranes of graftedcucumber had a higher stability and maintained longer.5. The grafted cucumber greatly changed in absorption of the plant mineral nutrition. The ratio of N,P and K partition to fruits of grafted one was smaller and the ones to nutrition organs were increased. The absorption of mass element of grafted cucumber had higher than own root one and the former should absorb N4.41kg, P1.19kg, K5.58kg,and the later only N4.19kg, P1.04kg, K5.99kg.We should increase the quantitative of fertilizer so as to acquired high yield of cucumber. In short ,the main reasons of higher yield in grafted cucumber were as follows: grafted cucumber had a higher utilization efficiency of CO2 and light than own root cucumber, leaves of grafted cucumber maintained longer stability and had a higher absorption of plant nutrition.