摘要
为探究新疆奇台荒漠区不同干旱程度和干旱时间作用下梭梭(Haloxylon ammodendron)幼苗生长生理的动态响应特征,以两年生盆栽幼苗为材料,模拟夏季高温时期荒漠土壤自然水分变化,以土壤田间持水量为基准,设置正常(田间持水量80%)、轻度干旱(田间持水量60%)、中度干旱(田间持水量40%)和重度干旱(田间持水量20%)处理,并持续胁迫40 d.每隔10 d利用卷尺和便携式光合仪监测幼苗的生长和生理指标,采用多重比较方法进行评价分析.结果表明,随着生境干旱加剧,幼苗株高和冠幅面积的增幅呈递减趋势,田间持水量60%处理持续胁迫10、20、30、40 d后,幼苗株高净增量的降幅较田间持水量20%处理的降幅分别小58.60%、38.18%、22.39%和7.49%.不同持续时间胁迫幼苗净光合速率的净减值由大到小依次是第40天、第30天、第20天和第10天,各干旱处理胁迫20 d后净光合速率的净减值相对最低,较胁迫40 d后分别低54.00%、61.00%和74.00%.幼苗在不同干旱条件下生长生理响应的差异特征表现为:田间持水量60%处理胁迫10 d后幼苗主要生长和生理指标的变幅显著低于其他干旱处理.
Abstract
In order to explore the dynamic response characteristics of the growth physiology of Haloxy-lon ammodendron seedlings under different drought gradients and drought time in the Qitai desert area of Xinjiang,biennial potted seedlings were used as materials to simulate the natural moisture changes in the desert soil during the high temperature period in summer,and the soil field water capacity was used as the benchmark to set up normal(field water capacity 80%),mild(field water capacity 60%),moderate(field water capacity 40%)and severe drought(field water capacity 20%)treatments,and the stress continued for 40 days.The growth and physiological indicators of the seedlings were monitored every 10 days using a tape measure and a portable photosynthetic instrument,and the multiple comparison method was used for evaluation and analysis.The results revealed that as the drought intensity of the habitat intensified,the increases in seedling plant height and crown area showed a decreasing trend,and the net increase in plant height decreased after 10,20,30,and 40 days of seedling stress under the field water capacity treatment of 60%,which were 58.60%,38.18%,22.39%and 7.49%lower than the 20%decrease in field water capaci-ty.The net decrease in the net photosynthetic rate of seedlings under different durations of stress from the largest to the smallest was on the 40th day,the 30th day,the 20th day and the 10th day.The net decreases in the net photosynthetic rate after 20 days of stress in each drought treatment were relatively at lowest level,which were 54.00%,61.00%and 74.00%lower than that after 40 days of stress.The differential characteristics of the growth physiological responses of seedlings under different drought conditions were as follows:the changes in the main growth and physiological indicators of seedlings after 10 days of stress in the field water capacity treatment of 60%were significantly lower than those of other drought treat-ments.
基金项目
国家自然科学基金(32260424)
国家自然科学基金(32160412)
新疆农业大学大学生创新项目(dxscx202312)
维普
万方数据