不同产量水平花生品种光合作用特性研究

用Li-6400手持式光合作用3分析系统，测定了8个具有不同产量水平花生品种4个生长时期的光合速率和相关的光合参数。结果表明，7个产量潜力较高的品种，尽管相互之间的产量差异在10％以上，但其光合强度（Pn)却没有明显差别，而引自印度的低产品种Isgv－9的光合强度则明显较低。所有品种中，位于主茎倒数第二或第三片完全展开的叶片，在荚果充实期（播种后52d)光合强度最大。叶片气孔导率（Cond)和胞间CO2浓度（Ci)与Pn显著相关，秋季夜间低温和Cond与Ci的降低，与生长后期（播种后88d)花生叶片光合强度的降低有关。叶片烫伤处理导致叶片光合作用、气孔导度和蒸腾速率迅速降低，而Ci却急剧升高，说明处理刺激了呼吸作用的进行。本研究的结果说明，对于产量潜力达到较高水平的花生品种，光合作用本身不是进一步提高产量的限制因素。

Photosynthetic characterization of peanut varieties differing in yield potential

Leaf photosynthesis and related traits at 4 growth stages of 8 peanut varieties difference in yield potential were studied using Li-6400 portable photosynthesis system.No significant difference in photosynthesis rate(Pn)was found among the 7 varieties with high yield potential,although their yield difference may be more than 10%,while one variety,Isgv-9,an Indian origin,had lower yield potential and significantly lower leaf Pn.The highest Pn occurred at the last second or third fully expended leaf and at pod enlarging stage(52 days after planting,DAP).Leaf stomata conductance(Cond)and intercellular CO2 concentration(Ci)were found to be higly correlated with Pn,and low night temperature and decrease of Cond and Ci is responsible for the low Pn in late growth stage(88 DAP).Leaf petiole girdling by hot water resulted in immediate dropdown of Pn,Cond and transpiration rate(Trmmol)but sharp increase of Ci,indicating a stimulated respiration.It is concluded that,for the peanut varieties with high yield potential,leaf Pn coordinates well with the growth conditions and Pn is not a limiting factor for further increase of yield.