金野紫穗槐对干旱胁迫的响应

The responses of Amorpha fruticosa‘Jinye’to drought stress

为了解金野紫穗槐在干旱胁迫下的形态、生长和生理响应特征,探明其抗旱能力,以其二年生扦插苗为试验材料、紫穗槐二年生扦插苗为对照材料,采用盆栽和持续停水的干旱处理方法,研究干旱胁迫对试验苗木生长以及渗透调节等生理指标的影响。结果表明,随着干旱胁迫时间的延长,土壤相对含水量逐渐降低,金野紫穗槐的土壤含水量下降幅度更大,30 d干旱胁迫结束时土壤重度干旱,相对含水量为24.42%。试验期间,金野紫穗槐和紫穗槐株高均持续增长、地径则先增长后降低,但株高和地径的增量均持续下降,表明干旱胁迫抑制了两个树种的株高和地径生长。两个树种的MDA和可溶性糖含量均随干旱胁迫时间延长逐渐上升;游离脯氨酸(Pro)含量金野紫穗槐呈先上升后下降趋势,紫穗槐呈持续上升趋势。结合隶属函数分析可知金野紫穗槐的抗旱性低于紫穗槐;灰色关联分析发现株高和MDA含量与抗旱性关联度最大,其次为Pro和可溶性糖含量。金野紫穗槐抗旱能力弱于紫穗槐,但在干旱胁迫下其各项指标反应良好,适合在干旱区种植,可作为优良的彩叶树种在干旱少雨地区推广应用。

In order to investigate the effects of continuous drought stress on characteristics of morphology,growth and physiology of Amorpha fruticosa‘Jinye’,and find out its drought-resistances,two-year-old cuttage seedlings of A.fruticosa‘Jinye’were used as experimental materials,and cuttage seedlings of A.fruticose L.were used as control materials.Potted and continuous drought treatment methods were used to study the effect of drought stress on growth and the physiological indexes such as osmoregulation.The results showed that with the prolongation of drought stress time,the relative water content of soil gradually decreased,and soil relative water content of A.fruticose‘Jinye’decreased more.At the end of 30-day drought stress,the soil of A.fruticose‘Jinye’was severely arid,and the relative water content was 24.42%.During the experiment,the seedling height increased continuously and the ground diameter increased first and then decreased,but the increment of seedling height and ground diameter decreased continuously,which indicated that drought stress inhibited the growth of seedling height and ground diameter of the two trees.The contents of MDA and soluble sugar in A.fruticose‘Jinye’and A.fruticose L.increased gradually with the extension of drought stress time;Proline(Pro)content of A.fruticose‘Jinye’displayed a trend of first increased and then decreased,while A.fruticosa L.continued to increase.In addition,subordinate function was used to rank their drought resistance and the order was A.fruticose L.>A.fruticose‘Jinye’.Grey relational analysis found that,plant height and MDA content had the highest correlation with drought resistance,followed by Pro and soluble sugar content.The indicators of A.fruticose‘Jinye’responded well under drought stress,and A.fruticose‘Jinye’showed a certain ecological adaptability,which was suitable for planting in arid areas,and could be used as an excellent colorful tree species in arid areas with little rainfall.