不同棉花栽培种的光合特性比较研究

Comparative analysis of photosynthetic characteristics of different cotton cultivars

对海岛棉"海7124"、亚洲棉"金华中棉"、非洲棉"红心棉"和陆地棉"苏12"4个棉花栽培种的光合参数和叶片荧光参数进行研究。结果显示,棉花叶片比叶重、叶绿素含量、Pn、Fv/Fm和qP均表现为"海7124">"苏12">"金华中棉">"红心棉",说明"海7124"具有高光效的特点。研究还表明,"海7124"、"金华中棉"、"苏12"光合速率日变化呈双峰曲线,"红心棉"为单峰曲线。光合速率日变化与气孔导度的日变化一致,中午光合速率的下降与气孔导度及PSII光化学效率降低有关。

The photosynthetic and fluorescence characteristics of ＂Hai7124＂（Gossypium barbadense）,＂Jinhuazhongmian＂（G.arboreum）,＂Hongxinmian＂（G.herbaceum） and ＂Su12＂（G.hirsutum） were analyzed in this paper.The results show that total chlorophyll content,leaf mass per area,Pn,PSⅡ photochemical efficiency（Fv/Fm） and photochemical quenching（qP） of the cotton cultivars are the following order： ＂Hai7124＂ 〉 ＂Su12＂ 〉 ＂Jinhuazhongmian＂ 〉 ＂Hongxinmian＂,indicating that ＂Hai7124＂ has higher photosynthetic efficiency.Further investigation shows that diurnal variation curves of Pn for ＂Hai7124＂,＂Jinhuazhongmian＂ and ＂Su12＂ have two peaks that occur at 12：00 and 16：00,though Pn for ＂Hongxinmian＂ varies and has a uni-peak curve that occurs between 12：00 ~ 14：00.This is consistent with diurnal variations in stomatal conductance（Cs）.Photoinhibition of photosynthesis at noon is related with decreasing Cs and PSⅡ photochemical efficiency.