摘要
为探究桑(Morus alba)树在重度干旱下的生理生化响应和适应能力,以农桑14号、农桑12号和强桑1号1年生盆栽苗为试验材料,采用盆栽称重控水的试验方法,控制30%田间持水量处理30d,模拟重度干旱对3种桑树生长、气体交换和保护酶含量的影响。结果表明:1)重度干旱导致3种桑树苗的净光合速率(Pn)、胞间二氧化碳浓度(Ci)、气孔导度(Gs)、蒸腾速率(Tr)均有显著下降,水分利用效率(WUE)、气孔限制值(Ls)均有显著上升。干旱胁迫导致3种桑树高生长速率显著降低。农桑14号和农桑12号的根干重(RDM)、茎干重(SDM)、叶干重(LDM)、总干物质量(TDM)均显著降低,而强桑1号对照与处理组之间无显著差异。农桑14号的超氧化物歧化酶(SOD)显著下降,过氧化物酶(POD)活性显著上升,强桑1号的丙二醛(MDA)含量显著上升。2)气孔关闭显著限制了3种桑树的净光合速率,而农桑14号和农桑12号同时存在非气孔因素的限制。3)农桑14号和农桑12号通过有效的形态调节(基部脱叶)和较强的气孔调节来适应极端干旱的环境,其水分利用方式更适合在湿润地区种植;强桑1号严格控制着各部分生物量的分配,相比于农桑14号和农桑12号,强桑1号更适合在干旱地区种植。
One-year-old potted seedlings of three mulberry varieties of Nongsang No.14,Nongsang No.12 and Qiangsang No.1 were investigated to estimate the effects of severe drought stress on plants,growth,leaf gas exchange and protective enzyme activity,to explore adaptive mechanisms of Morus L.to water stress.The soil moisture was controlled by weighting the pots.The pots relative soil water content came to the 30% of maximum field capacity of soil and kep one-month treatment.The results showed that 1）the drought treatment significantly decreased net photosynthetic rate（Pn）,stomatal conductance（Gs）,transpiration rate（Tr）and intercellular CO2 concentration（Ci）,however it improved water-use efficiency（WUE）and increased limiting value of stomata（Ls）.The severe drought stress decreased the relative height growth rate（RHG）for all three varieties.Moreover,the root dry mass（RDM）,steam dry mass（SDM）,leaf dry mass（LDM）and total dry mass（TDM）of Nongsang No.14 and Nongsang No.12 had a significant decline,however the decline was not found on Qiangsang No.1.The SOD activity of Nongsang No.14 de-creased,while the POD activity of Nongsang No.14 increased.Heavy drought led to a significant higher MDA content in Qiangsang No.1.2）The stomatal limitation decreased the Pnsignificantly in three varieties of potted Morus L.seedlings,meanwhile the non-stomatal limitation also existed in Nongsang No.14 and Qiangsang No.1.3）Nongsang No.14 and Nongsang No.12 responded to heavy drought stress by efficient morphological adjustment combined with strong stomatal conductance to control water use efficiency under the severe drought stress,and this water-using strategy maybe more suitable for cultivating in humid regions.While Qiangsang No.1 water-using strategies were to control the biomass allocation,especially control above ground biomass,compared to Nongsang No.14 and Nongsang No.12,it maybe more suitable for cultivating in arid regions.
作者
郑俊明
吕志强
孙志鸿
ZHENG Jun-ming;LU Zhi-qiang;SUN Zhi-hong(School of Forestry and Biotechnology,Zhejiang Agriculture and Forestry University,Lin＇an,Zhejiang 311300,China;Sericultural Research Institute,Zhejiang Academy of Agriculture Sciences,Hangzhou,Zhejiang 310021,China)
出处
《西北林学院学报》
CSCD
北大核心
2018年第4期44-51,共8页
Journal of Northwest Forestry University
基金
浙江农林大学科研发展基金项目(2014FR087)
浙江省科技计划项目(2016C32018)
浙江省农业新品种选育重大科技专项(2016C02054-17)
关键词
桑树
重度干旱
保护酶
气体交换
生物量
Morus L.
severe drought stress
protective enzyme
leaf gas exchange
biomass
