Abstract: Effects of phosphorus (0, 1, 5 and 20 mmol稬^-1) on the biomass and photosynthesis of Zoysia matrella were investigated under salt stress (300 mmol稬^-1 NaCl) using hydroponic method. Results showed that NaCl stress decreased plant growth. Shoot dry weight and root dry weight of Zoysia matrella were promoted with increasing P concentration, and they were inhibited when P concentration was 20 mmol稬^-1. Chlorophyll and carotenoid contents were increased under salt stress, but they were not significantly affected by increasing P concentration. Salt stress decreased net photosynthesis rate, stomatal conductance, intercellular CO₂ concentration and transpiration rate, which was relieved with increasing P concentration. Although salt sensitive index was decreased with increasing P concentration, the reasonable amount of P can improve the salt resistance of Zoysia matrella by promoting the photosynthetic rate and growth of plant.

Key words: Zoysia matrella, Phosphorous, Salt tolerance, Growth, photosynthetic rate

摘要： 采用水培法研究了NaCl胁迫下(300 mmol·L^-1)不同浓度磷素(0, 1, 5和20 mmol·L^-1)对沟叶结缕草(Zoysia matrella)生物量及光合作用的影响。结果表明:NaCl胁迫显著抑制了沟叶结缕草的生长。随培养液中磷浓度增加,沟叶结缕草的枝叶干重和根系均受到促进,但在20 mmol·L^-1 磷浓度处理时植株的生长反而受到一定的抑制。NaCl胁迫下,沟叶结缕草的叶绿素和类胡萝卜素含量有所增加,但是磷处理对色素的影响很小。盐处理降低了植株的净光合速率、气孔导度、胞间CO₂浓度和蒸腾速率,施加磷能在一定程度上缓解盐胁迫的效应。尽管随着磷素增加,盐敏感指数(SI)下降,但适量磷浓度促进了沟叶结缕草的绝对生长,提高了叶片的光合速率,从而提高其抗盐性。

关键词: 沟叶结缕草, 磷, NaCl胁迫, 生长, 光合特性