温室黄瓜叶面积扩展与光合特性对土壤水分的响应研究

温室盆栽试验研究土壤水分对黄瓜叶面积扩展与光合特性的影响结果表明,黄瓜叶片扩展经历了指数生长(EG)、线性生长(LSG)和稳定生长(SCG)3个阶段。随土壤含水量的增加,叶面积(LA)显著增大,叶片生长速率(LGR)的最大值明显提前。叶片相对扩展速率(RER)在指数生长阶段迅速增加,但在线性生长和稳定生长阶段则逐渐减小。土壤含水量显著影响了叶片的扩展和光合特性。叶片生长进程中,叶绿素含量和净光合速率(Pn)逐渐增加,处理间差异明显,不同水分处理的叶片净光合速率日变化均表现为单峰曲线,其表观量子效率(AQY)、羧化效率(CE)具有显著差异。

Response of leaf area expansion and photosynthetic characteristics of cucumber to soil water status in greenhouse

The potted experiment of cucumber in greenhouse was conducted to study the effects of soil water status on leaf area expansion and photosynthetic characteristics.The results show that there are three growing phases during leaves expansion of cucumber,exponential growth phase(EG),linear scale growth phase(LSG)and stability constant growth phase(SCG).With the soil water content increasing,the leaf area(LA)enlarges significantly,and the maximum of leaf growth rate(LGR)appears obviously early.The relative expansion rate(RER)of leaves increases at the EG phase,but gradually reduces at the LSG and SCG phases.Soil moisture significantly influences the leaf expansion and photosynthetic characteristics.During the proceeding of leaf growth,the chlorophyll content and net photosynthetic rate(Pn)increase gradually with significant differences among treatments.The diurnal variations of Pn of all treatments demonstrate a single peak curve.The apparent quantum yield(AQY)and carboxylation efficiency(CE)of cucumber leaves among different treatments show significant differences.