机构地区:[1]中国气象局兰州干旱气象研究所,甘肃省干旱气候变化与减灾重点实验室,中国气象局干旱变化与减灾重点开放实验室,兰州730020
出 处:《生态学杂志》2023年第11期2622-2629,共8页Chinese Journal of Ecology
基 金:国家自然科学基金项目(41975151);甘肃省青年科技基金项目(20JR10RA451);甘肃省基础研究创新群体项目(20JR5RA121)资助。
摘 要:以半干旱区马铃薯为试验材料,利用人工补水及自然控水的方法,测定分析马铃薯叶片在不同水分条件下光合生理参数的光响应过程及对土壤水分响应规律的阈值效应,水分梯度设置土壤含水量为田间持水量55%、65%和75%为干旱胁迫处理,土壤含水量为田间持水量80%为对照,土壤含水量为田间持水量85%为渍水处理。结果表明:马铃薯叶片净光合速率(P_(n))、水分利用效率(WUE)及光响应参数具有明显的水分临界效应。表观量子效率(AQY)、最大净光合效率(P_(nmax))、光饱和点(LSP)随土壤含水量的增大呈先增加后降低的变化趋势,光补偿点(LCP)、暗呼吸速率(Rd)则先降低后增加。在渍水或干旱胁迫下,马铃薯叶片在弱光下的吸收、转换光的能力降低,在强光和弱光利用方面受到抑制,并且通过减少呼吸消耗维持干物质积累。P_(n)、WUE随土壤水分的增加呈先升高后降低趋势,但水分临界值不相同,土壤相对含水量(W_(r))为56.7%时为马铃薯叶片气孔限制的临界点,W_(r)为96.3%时为Pn的水分饱和点,W_(r)为70.1%时为WUE的高效点,马铃薯在渍水条件下叶片的光合能力高于干旱胁迫处理。通过数学模型确定半干旱区马铃薯的水分阈值,当Wr在70.1%~96.3%时为高产高效水,此时马铃薯的光合生产力和水分利用效率较高。因此,Wr在70.1%~96.3%时是半干旱区马铃薯较适宜生长的土壤水分条件,半干旱地区渍水条件下马铃薯的光合能力明显高于干旱胁迫处理。Using artificial water supplementation and natural water control methods,we measured the light response process of photosynthetic physiological parameters of potato leaves under different water conditions and further ana⁃lyzed the threshold effects for the responses to soil water.Soil moisture was set as 55%,65%and 75%field water⁃holding capacity for drought stress treatments,80%field water⁃holding capacity for control treatment and 85%field water⁃holding capacity for waterlogging treatment.The results showed that net photosynthetic rate(P_(n)),water use efficiency(WUE),and light response parameters of potato leaves had obvious water critical effects.The apparent quantum efficiency(AQY),maximum net photosynthetic efficiency(P_(nmax)),and light saturation point(LSP)in⁃creased first and then decreased with increasing soil water content,while light compensation point(LCP)and dark respiration rate(Rd)first decreased and then increased.Under waterlogging or drought stress,the ability of light absorption and conversion of potato leaves under weak light was reduced,the utilization of strong light and weak light was inhibited,and dry matter accumulation was maintained by reducing respiratory consumption.With increa⁃sing soil moisture,Pn and WUE increased first and then decreased,but the critical values of moisture were different.The relative soil water content(W_(r))at 56.7%was the critical point of stomatal limitation in potato leaves.The W_(r) at 96.3%was water saturation point of Pn,and Wr at 70.1%was the high efficiency point of WUE.Photosynthetic capacity of potato leaves under waterlogging was higher than that under drought stress.The moisture threshold of po⁃tato in semi⁃arid area was determined by mathematical model.The W_(r) value between 70.1%and 96.3%was high⁃yield and high⁃efficiency water,in which the photosynthetic productivity and water use efficiency of potato were higher.Therefore,Wr between 70.1%and 96.3%is suitable for potato growth in semi⁃arid area.Photosynthetic capacity of pot
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