种植密度对穿心莲农艺性状、碳氮代谢和活性成分的影响

Effects of Planting Density on Agronomic Traits, Carbon and Nitrogen Metabolism and Bioactive Ingredients in Andrographis paniculata

以药用植物穿心莲为试材,采用大田小区试验,研究了4种种植密度(T_(1):40 cm×40 cm;T_(2):40 cm×30 cm;T_(3):30 cm×20 cm;T_(4):20 cm×20 cm)对农艺性状、碳氮代谢和穿心莲内酯积累的影响,以期为穿心莲合理密植提供参考依据。结果表明:随种植密度增加,植株株高增加,冠幅和叶绿素a/b下降。单株生物量随种植密度增加而下降,T_(3)和T_(4)分别较T_(1)降低24.2%和46.2%;相反,T_(3)和T_(4)单位面积产量分别较T_(1)提高1.02倍和1.15倍。T_(3)、T_(4)增加了茎秆中蔗糖的积累,但随着种植密度增加,叶片和茎秆(T_(3)除外)淀粉积累减少,叶片总氮含量和氮代谢酶谷氨酰胺合成酶(GS)、谷氨酸合成酶(GOGAT)、谷草转氨酶(GOT)和谷丙转氨酶(GPT)等活性增加。T_(4)条件下叶片和茎秆穿心莲内酯含量分别较T_(1)下降了23.9%和38.9%。叶片和茎秆中穿心莲内酯含量分别与相应器官中总氮含量呈显著负相关和正相关,叶片中穿心莲内酯含量与淀粉含量也呈显著正相关。综上表明,提高种植密度促进了穿心莲氮代谢,增加了碳水化合物消耗,从而降低穿心莲内酯积累。综合考虑穿心莲产量和内酯含量,以株行距30 cm×20 cm最适宜。

Taking medicinal plant Andrographis paniculata as test material,the effects of planting densities(T_(1)40 cm×40 cm,T_(2)40 cm×30 cm,T_(3)30 cm×20 cm,T_(4)20 cm×20 cm)on agronomic traits,carbon and nitrogen metabolism,and andrographolide accumulation were studied,in order to provide a reference for the rational close planting of Andrographis paniculata.The results showed that with the increase of planting densities,plant height increased,but crown width and chlorophyll a/b decreased.The biomass per plant decreased with the increase of planting densities,and T_(3) and T_(4) decreased by 24.2%and 46.2%,respectively,compared with T_(1).In contrast,the yield per unit area of T_(3) and T_(4) increased by 1.02 times and 1.15 times,respectively,compared with T_(1),T_(3) and T_(4) increased the accumulation of sucrose in stems.With the increase of planting densities,the accumulation of starch in leaves and stems(with the exception of T_(3))decreased,and the total leaf nitrogen content and the activities of nitrogen metabolic enzymes such as glutamine synthase(GS),glutamate synthase(GOGAT),glutamic-oxaloacetic transaminase(GOT)and glutamic-pyruvic transaminase(GPT)increased.Under the condition of T_(4),andrographolide contents in leaves and stems decreased by23.9% and 38.9%respectively,in comparison to T_(1).Andrographolide content in leaves and stems was significantly negatively and positively correlated with total nitrogen content in corresponding organs,respectively.Andrographolide content in leaves was also positively correlated with leaf starch content.The results showed that increasing planting density promoted nitrogen metabolism of Andrographis paniculata plants,and therefore increased consumption of carbonhydrates and reduced andrographolide accumulation.Considering the yield and andrographolide content,the density of30 cm×20 cm was preferable for Andrographis paniculata planting.