膜下滴灌条件下不同田间持水量对马铃薯生理特性及产量的影响

Effects of different field water capacity on physiological characteristics and yield of potato under drip irrigation with plastic mulch

本试验以马铃薯品种‘海斯薯’为试验材料,于2018年和2019年在大田遮雨棚和膜下滴灌条件下设置6个田间持水量梯度处理(分别为85%~95%、75%~85%、65%~75%、55%~65%、45%~55%和不灌水处理),研究了不同田间持水量对马铃薯叶片的生理特性(SOD、MDA、Pro)、光合特性(P_(n)、C_(i)、G_(s)、L_(s))及块茎产量的影响。结果表明,随田间持水量的降低,P_(n)和G_(s)逐渐下降,MDA和Pro含量逐渐升高,L_(s)和SOD活性呈先升后降的变化趋势,而C_(i)则呈先降后升的变化趋势。其中,持水量65%~95%处理的P_(n)和G;显著高于其他处理(P<0.05);持水量55%~65%处理的SOD活性和L_(s)显著高于其他各处理(P<0.05),但其C_(i)最低。根据C_(i)和L_(s)的变化趋势分析得出:持水量55%~65%可能为气孔限制与非气孔限制因素的临界区间。持水量55%~65%处理下MDA和Pro含量显著高于其他各处理(P<0.05),说明田间持水量低于55%以下时,膜脂过氧化程度较高,植物细胞受到严重损伤;持水量高于65%处理下的块茎产量显著高于其他处理,相较于不灌水处理显著增加了138.82%~257.61%,补偿效应显著(P<0.05);其中,持水量75%~85%处理下产量最高,平均产量为4.53 kg·m^(-2)。

The potato(Solanum tuberosum)variety’Hermes’was grown in the field under a rain shelter and film mulching with drip irrigation under six field water capacity gradient treatments(85%–95%,75%–85%,65%–75%,55%–65%,45%–55%and non-irrigation)in 2018 and 2019 to investigate the effects of different field water capacity on physiological characteristics(SOD,MDA,Pro),photosynthetic characteristics(P_(n),C_(i),G_(s),L_(s))of potato leaf and tuber yield.The result showed that with the decrease of field water capacity,P_(n)and G_(s) were gradually decreased,and the contents of MDA and Pro were gradually increased,the activity of SOD and L_(s)showed a trend of increasing first and then decreasing,while C_(i) showed a trend of decreasing first and then increasing.Among them,P_(n)and G_(s) were significantly higher under the field water capacity of 65%–95%than those under other treatment(P<0.05).The SOD activity and L_(s)were significantly higher under the field water capacity of 55%–65% than those under the other treatments(P<0.05),whereas the C_(i) was the lowest.The results suggested that the field water capacity of 55%–65%might be stomatal and non-stomata limitation to photosynthetic according to the change trend of C;and L_(s).The contents of MDA and Pro were significantly higher under the field water capacity less than 55%than those under the other treatments(P<0.05).The results indicated that the plant could cause serious damage when the water capacity in the field was less than 55%.Tuber yield was significantly higher under the field water capacity of 65%–95%than those under other treatment,and increased by 138.82%–257.61%compared with non-irrigation treatment,and the compensation effect was significant(P<0.05).Among them,the field water capacity of 75%–85%treatment had the highest yield,with an average yield of 4.53 kg·m^(-2).