不同损伤对合作杨光合特性的影响

Effects of three types of wound on photosynthetic activity of Populus simonii × P. pyramidalis ‘Opera 8277’ seedlings

以1年生合作杨扦插苗为材料,进行机械损伤、茉莉酸甲酯熏蒸和杨扇舟蛾取食3种损伤,研究了不同损伤对合作杨光合特性的影响。结果表明:3种损伤都导致了净光合速率的显著降低,且机械损伤和茉莉酸甲酯熏蒸对净光合速率的影响大于取食对净光合速率的影响。机械损伤后净光合速率下降的主要原因是气孔性限制,而茉莉酸甲酯熏蒸和取食后净光合速率下降的主要原因是非气孔性限制。3种损伤都可逆地降低了PSⅡ的最大光化学效率,但对光化学淬灭和非光化学淬灭没有显著的影响,这表明3种损伤对PSⅡ反应中心的影响是暂时的、可逆的。

The effect of three types of wound treatment,i.e. methyl jasmonate （MeJA） fumigation,mechanical wounding and herbivory by Clostera anachoreta,on photosynthesis of one-year-old potted Populus simonii× P. pyramidalis ‘Opera 8277’ seedlings were investigated. The results indicated that the net photosynthetic rate （P_n） decreased significantly under all treatments. P_n decreased more as a result of mechanical wounding and MeJA fumigation than of herbivory. The decrease of P_n with mechanical wounding was caused by stomatal limitation,while those with MeJA fumigation and herbivory were due to non-stomatal limitations. The maximum efficiency of Photosystem Ⅱ （F_v/F_m） was temporarily impaired after treatments. There was no statistically significant difference in photochemical quenching （q_p） and non-photochemical quenching （NPQ）,suggesting that the damage to the action center of PS Ⅱ is reversible.