Effects Of Substrate Moisture And Light Levels On The Growth, Development And Physiology Characteristics Of Muskmelon (Cucumis Melo L.)

Two muskmelon varieties 'Xiyuyihao' and 'Xiboluotuo' were used as test materials to study the effects of substrate moisture and light levels on the growth, physiological and photosynthetic characters. 12 treatment combinations were compared in this experiment, with 4 levels of water-holding capacity (100%, 80%, 60% and 40%) and 3 levels of light density (100%, 70% and 40%). The results were as follows,1. The two varieties of muskmelon seedlings showed similar reactions to different treatments. The plant height decreased with the reduction of substrate moisture. As to the factor of substrate moisture, both the extremely high level (100% water-holding capacity) and the low level (40% water-holding capacity) lead to a remarkable decrease in dry weight, root to shoot ratio and healthy index. As to the factor of light environment, an appropriate shading (70% light density) lead to a significant growth in plant height. Weak light treatment remarkably decreased the stem diameter, dry weight and healthy index.Under the different treatments, W₂L₁ (80% water-holding capacity +100% light density) muskmelon seedling exhibited strong growth vigor, high healthy index and photosynthetic rate. The results indicated that the maximum vatiety of pollination date, harvest date, days during fruit development among different treatments of the variety'Xiboluotuo' were 9 days, 11 days, 4 days respectively. The treatment of W₂L₁ has the shortest days of fruit development and the earliest harvest date ,but W₂L₂ (80% water-holding capacity+70% light density) has the heaviest single fruit mass.2. At different light levels, the plant exhibited an increase in soluble reducing sugar content, soluble protein content and Pro with the reduction of substrate moisture, while the leaf moisture capacity and SLA decreased. At a same light level, the plant exhibit a remarkable higher content of MDA to both the extreme high or low water-holding capacity compared to other substrate moisture treatments. However, under full light environment, the plant exhibit a remarkable lower content of ASA, and under 70% light density or full...