行距和播量对河北滨海盐碱地苜蓿光合特性及产量的影响

Effects of Row Spacing and Sowing Rate on Photosynthetic Characteristics and Yield of Alfalfa in Coastal Saline-alkali Soil in Hebei Province

为揭示行距和播量对河北滨海盐碱地苜蓿光合特性及产量的影响,本研究以‘中苜一号’为材料,设置了15 cm(R1),20 cm(R2),25 cm(R3)3个水平的行距和7.5 kg·hm^(-2)(S0),15 kg·hm^(-2)(S1),22.5 kg·hm^(-2)(S2),30 kg·hm^(-2)(S3),37.5 kg·hm^(-2)(S4)5个水平的播量,共15个处理,研究了苜蓿叶片色素含量、荧光参数、光合曲线及产量的变化规律。结果表明:随着行距的增大苜蓿叶片叶绿素含量(Chlorophyll content,ChlM)和氮-黄酮醇指数(Nitrogen flavonol index,NFI)均呈下降趋势,R1S2处理的苜蓿叶片NFI最高。通径分析表明,行距和播量配置通过调节叶片ChlM,花青素含量(Anthocyanin content,AnthM),黄酮醇含量(Flavonol content,FlvM),最大光合效率(Maximal photochemical efficiency,F v/F m),调节性能量耗散的量子产量(Quantum yield of regulatory energy dissipation,Y(NPQ))和表观光合电子传递速率(Electron transfer rate,ETR)影响苜蓿光合作用和产量的形成。在本研究条件下,行距15 cm、播量约22 kg·hm^(-2)配置下苜蓿产量最高。

This study was conducted to reveal the effects of row spacing and sowing rate on the photosynthetic characteristics and yield of alfalfa in coastal saline-alkali soil in Hebei Province.The Medicago sativa‘Zhongmu No.1’was used as the tested material,the row spacing were set up at 15 cm(R1),20 cm(R2),25 cm(R3),in the same time the sowing rate were set at 7.5 kg·hm^(-2)(S0),15 kg·hm^(-2)(S1),22.5 kg·hm^(-2)(S2),30 kg·hm^(-2)(S3)and 37.5 kg·hm^(-2)(S4).The change of pigment content,fluorescence parameters,photosynthetic curve,and yield of alfalfa under 15 treatments were investigated.The results showed that chlorophyll content(ChlM)and nitrogen flavonol index(NFI)of alfalfa leaves decreased with the increase of row spacing,and the NFI of alfalfa leaves treated with R1S2 was the highest among all treatments.Path analysis showed that row spacing and sowing rate affected plant photosynthesis and yield formation by regulating alfalfa ChlM,anthocyanin content(AnthM),flavonol content(FlvM),maximal photochemical efficiency(F v/F m),Quantum yield of regulatory energy dissipation(Y(NPQ))and table apparent electron transfer rate(ETR)of alfalfa leaves.Under the conditions of this study,when the row spacing was 15 cm and the sowing rate about 22 kg·hm^(-2),alfalfa would achieve the highest yield.