不同密度椰林间作荫蔽对花生光合特性的影响

花生是我国重要的经济和油料作物,海南岛独特的地理条件和气候优势适合花生生长,发展椰林下间作花生有利于提高海南省花生种植面积,促进花生种植业在海南的发展。花生为喜光作物,为揭示不同光照环境对花生光合特性和产量的影响,以‘本红1号’为材料,在单作人工荫蔽和椰林间作自然荫蔽条件下,分析不同荫蔽度与花生叶片叶绿素含量、光合参数、荧光参数和间作花生产量的关系。结果表明,人工荫蔽和自然荫蔽均对花生光合作用有显著影响,2种荫蔽处理均证明荫蔽能促进花生叶片叶绿素含量的增加。在人工荫蔽条件下,随荫蔽度增加至65%,花生叶绿素含量显著上升;在自然荫蔽条件下,25%~35%荫蔽处理下花生叶片的总叶绿素含量显著大于其他荫蔽处理组。在人工荫蔽条件下,25%荫蔽度下花生的净光合速率P_n,23.06 µmol/(m²·s)]、蒸腾速率T_r,6.61 mmol/(m²·s)]、气孔导度G_s,606.21 mmol/(m²·s)]最高;在自然荫蔽条件下,15%~25%荫蔽度处理（4 m×6 m椰林）的花生P_n18.27 µmol/(m²·s)]、T_r7.66 mmol/(m²·s)]、G_s618.10 mmol/(m²·s)]最大。在人工荫蔽条件下,花生可变荧光和最大荧光先显著增高后显著降低,在自然荫蔽条件下无显著差异。产量结果显示,与花生单作对照相比,不同密度椰林间作荫蔽均能够显著提高花生产量。本研究证明适度荫蔽能够促进花生光合作用,4 m×6 m（15%~25%荫蔽度）为间作花生推荐的椰林种植密度,可为构建高产高效的椰园花生间作模式提供科学参考。

Effects of Coconut Forest Intercropping with Different Densities on Photosynthetic Characteristics of Peanut

Peanut is an important economic and oil crop in China. The unique geographical conditions and climate advantages in Hainan are suitable for peanut growth. The development of peanut intercropping under coconut forest is conducive to improving the peanut planting area in Hainan and promoting the development of peanut planting industry in Hainan. Peanut is a photophilic plant and intercropping under forest has a certain impact on the photosynthetic characteristics of peanut. In order to reveal the effects of different light environments on peanut photosynthetic characteristics and yield, Benhong 1 was used as material to analyze the relationship between different shading degrees and peanut leaf chlorophyll content, photosynthetic parameters, fluorescence parameters and intercropping flower production under the conditions of monoculture artificial shading and coconut forest Intercropping natural shading. The results showed that both artificial and natural shading had significant effects on peanut photosynthesis. Both shading treatments proved that shading could promote the increase of chlorophyll content in peanut leaves. Under the condition of artificial shading, the chlorophyll content of peanut increased significantly with the increase of shading degree to 65%. Under natural shading conditions, the total chlorophyll content of peanut leaves under 25%-35% shading treatment was significantly higher than that of other shading treatment groups. Under artificial shading, 25% shade treatment net photosynthetic rate of peanut P_n, 23.06 µmol/(m²?s)], transpiration rateT_r, 6.61 mmol/(m²?s)], stomatal conductance G_s, 606.21 mmol/(m²?s)] were the highest. Under natural shade conditions, 15%-25% shade treatment (4 m×4 m peanut) P_n 18.27 µ mol/(m²?s)], T_r7.66 mmol/(m²?s)], G_s618.10 mmol/(m²?s)] were the highest. The yield results showed that compared with the peanut monoculture control, the intercropping shade of coconut forests with different densities could significantly improve the yield of peanut. This study showed that moderate shade could promote peanut photosynthesis, 4 m×6 m (15%-25% shade) is the recommended planting density of coconut forest for intercropping peanut, which could provide a scientific reference for constructing a high-yield and efficient intercropping model of coconut garden peanut.