遮荫弱光对甜瓜产量及光合特性的影响

Effect of Shading on Yield and Photosynthetic Characteristics of Muskmelon

【目的】研究遮荫弱光对甜瓜光合特性、产量和品质的影响,分析遮荫弱光影响甜瓜的生理机制过程。【方法】以新疆当地3个甜瓜品种为材料,设置适度遮荫、轻度遮荫和不遮荫3个处理,测定光合指标、SPAO值和果实产量与品质,数据运用SPSS 19.0软件分析。【结果】与正常光照相比,遮荫弱光造成甜瓜叶片SPAD值、气孔导度(Gs)、净光合速率(Pn)和蒸腾速率(Tr)迅速降低,胞间CO 2浓度(Ci)上升,甜瓜果肉中的可溶性固形物、可溶性糖、可溶性蛋白含量、折光糖和VC含量均下降。卡拉库塞的相关指标变化幅度较其力甘和比谢克沁小。【结论】不同甜瓜品种对遮荫弱光胁迫的适应性亦不同。甜瓜在轻度遮荫和重度遮荫环境下,其光合性能下降,光合产物累积能力及输出能力受阻,最终甜瓜产量和品质亦随遮荫程度加深而显著降低(P<0.05)。

【Objective】To study the effects of shade and light on photosynthetic characteristics,yield and quality of muskmelon with a purpose of exploring the physiological mechanism of shade and light affecting the fruit.【Method】Based on three local melon varieties in Xinjiang,the experiment was carried out in 2019 at the comprehensive experimental site of Xinjiang Academy of Agricultural Sciences(87°28′E,45°56′N)at No.1 Xiaokang Road,Anning District,Urumqi City,Xinjiang.【Result】Compared to normal light,the shading weak light resulted in a rapid decrease in chlorophyll SPAD value,stomatal conductance(G s),net photosynthetic rate(P n)and transpiration rate(T r)in muskmelon leaves,an increase in intercellular CO 2 concentration(C i),and a decrease in soluble solids,soluble sugars,soluble protein content,refractive sugar and vitamin C in melon pulp.The change range of Kalakusai was smaller than that of Bixiekeqin and Qiligan.【Conclusion】The adaptability of different ecotypes of muskmelon to shade and low light environment is different.Under the condition of mild and severe shading,the photosynthetic performance of muskmelon leaves decrease,the accumulation and output of photosynthetic products are blocked,and the final yield and quality of muskmelon decrease significantly with the deepening of shading(P<0.05).