开花期与块茎膨大期干旱胁迫及旱后复水对马铃薯影响的差异

2021年4-7月在沈阳农业大学大型水分控制试验场进行马铃薯的控水实验，选取马铃薯开花期和块茎膨大期，设置轻度干旱（开花期土壤相对湿度50%、块茎膨大期土壤相对湿度60%）、中度干旱（开花期土壤相对湿度40%、块茎膨大期土壤相对湿度50%）和重度干旱（开花期土壤相对湿度30%、块茎膨大期土壤相对湿度40%）以及对照（开花期土壤相对湿度70%、块茎膨大期土壤相对湿度80%）处理，在每一个生育阶段各级干旱处理5d后进行复水，复水水平控制到对照处理水平，研究干旱胁迫及旱后复水对马铃薯光合特性、叶绿素荧光、生长及产量的影响。结果表明：开花期与块茎膨大期遭遇干旱胁迫会使叶片气孔导度、净光合速率均显著低于对照处理，叶片光系统II的光化学淬灭系数、光能转换率显著降低，非光化学淬灭系数显著升高。开花期轻度干旱持续5d后复水，叶片净光合速率比干旱处理提高20%，但块茎膨大期中、重度干旱恢复的程度很小。各级干旱处理下叶面积指数较对照下降17.6%～50.3%，干物质重降低23.4%～51.4%；开花期各级干旱处理下的马铃薯产量，分别较对照处理减少1.0%～19.6%，而块茎膨大期各级干旱处理下的马铃薯产量...

Effects of Drought Stress and Post-drought Rewatering on Potato during Flowering and Tuber Expansion Periods

A water control experiment of potato was conducted in Shenyang Agricultural University from April to July, 2021. Potato flowering period and tuber expansion period were selected, and the mild drought (relative soil moisture during flowering period is 50% and that during tuber expansion period is 60%), moderate drought (relative soil moisture during flowering period is 40% and that during tuber expansion period is 50%) and severe drought (relative soil moisture during flowering period is 30% and that during tuber expansion period is 40%) and control (relative soil moisture during flowering period is 70% and that during tuber expansion period is 80%), rewatering treatment was carried out after 5 days of drought at all levels in each growth period, and the rewatering level was controlled to the control level. The effects of drought stress and post-drought rewatering on photosynthetic characteristics, chlorophyll fluorescence, growth and yield of potato were studied. The results showed that the stomatal conductance and net photosynthetic rate of leaves under drought stress during flowering and tuber expansion period were significantly lower than those under control, moreover, the photochemical quenching coefficient and light energy conversion ratio of leaf photosystem II were significantly decreased, whereas the non-photochemical quenching coefficient was significantly increased. Rewatering after 5 days of mild drought during flowering period, the leaf net photosynthetic rate increased by more than 20% compared with that of drought treatment, but the recovery degrees under moderate and severe drought during tuber expansion period were very small. Leaf area index and dry matter weight decreased by 17.6%?50.3% and 23.4%?51.4% under different drought treatments compared with control. Compared with the control, the potato yield under different drought treatments decreased by 1.0%?19.6% during flowering period, whereas that decreased by 8.6%?30.5% during tuber expansion period. The reduction in potato yield caused by drought during tuber expansion period was greater than that during flowering period. In conclusion, drought stress can inhibit the growth process of potato leaves, reduce photosynthetic products, and ultimately lead to the reduction in yield. Rewatering in time can alleviate the effects of drought stress on potato and achieve the stable and high yield of crops.