模拟淹水对杞柳生长和光合特性的影响

Effect of flooding stress on growth and photosynthesis characteristics of Salix integra

以1年生红皮柳(Salix integra cv.hongpi)和青皮柳(Salix integra cv.qingpi)为试验材料,研究了人工模拟淹水胁迫对两个杞柳品种的生长、气体交换及叶绿素荧光的影响。经过75d的淹水处理,两个品种的存活率均为100%。在试验过程中,红皮柳和青皮柳都产生了有利于吸收氧气的不定根和肥大的皮孔,但在产生的时间上红皮柳较青皮柳迟10d左右。渍水处理促进了青皮柳的生长和光合作用,而红皮柳在渍水和轻度淹水胁迫处理下的生长、叶绿素含量(Chl)、净光合速率(PN)和气孔导度(Gs)都明显低于对照。随着淹水时间的增加,红皮柳的非光化学淬灭系数(NPQ)持续增加并高于对照,最大光化学量子效率(Fv/Fm)持续下降且明显低于对照;青皮柳的非光化学淬灭的值增加幅度较小,最大光化学量子效率一直在0.8—0.85之间波动,与对照相比都无显著差异。以上的实验结果表明在淹水胁迫下红皮柳的光合运转机构受到了一定程度的损伤,而渍水处理则促进了大青皮的生长,因此青皮柳较红皮柳而言更耐淹,更适合在河岸带和消落区生长。

The effects of flooding on growth, leaf gas exchange and chlorophyll fluorescence of Salix integra seedlings were studied during a growth season （from August to October in 2011 ）. Throughout a 75 day flooding period, the survival rates of seedlings of the two types of Salix integra were 100%. The seedlings of both types developed hypertrophied lenticels and adventitious roots at their stem base with the different formation time （Salix integra cv. hongpi was 10d later than Salix integra cv. qingpi）. The growth and photosynthesis of S. integra cv. qingpi were promoted under the waterlogging stress, while the growth and photosynthetic properties （chlorophyll （Chl） content, net photosynthetic rate （PN） and stomatal conductance （ Gs ） ） of S. integra cv. qingpi under waterlogging stress and slight flooding stress were all significantly lower than those of the control. Significant increases of non-photochemical quenching （NPQ） and reductions of maximal quantum efficiency of PS 11 photochemistry （ Fv/Fm ） in the flooded seedlings were observed for S. integra cv. hongpi. For S. integra cv. qingpi, however, the value of Fv/Fm was fluctuated from 0.80 to 0.85. There were no significant differences in NPQ and Fv/Fm between the treatments and control. Our results demonstrated that S. integra cv. hongpi of S. integra appeared a slight damage to its photosynthetic apparatus under slight flooding stress. In contrast, the slight flooding stress promoted the growth of S. integra cv. qingpi, indicating that S. integra cv. qingpi can tolerate prolonged soil flooding better than S. integra ev. hongpi. Thus S. integra cv. qingpi is more suitable for afforestation in the riparian zone.