干旱胁迫对文冠果树苗某些生理特征的影响

Research on physiological mechanism about Shinyleaf Yellowhorn seedling responding to water stress

盆栽条件下设置不同土壤水分含量(土壤绝对含水量为13%、18%和25%),分析了干旱胁迫对文冠果叶片水势、细胞膜透性、渗透调节物质及超氧化物歧化酶(SOD)酶活性等的影响。结果表明:13%和18%土壤含水量条件下文冠果枝条分别达到中度水分胁迫和轻度胁迫程度,文冠果叶片细胞膜透性分别高出对照(土壤绝对含水量为25%)16%和4%;文冠果叶片积累的可溶性糖分别是对照的2.3和1.2倍,积累的脯氨酸分别比对照增加了21%和8%;叶片SOD活性分别下降了5%和3%,过氧化氢酶(CAT)活性下降幅度较大,分别比对照下降83%和68%;MDA积累量分别比对照增加了44%和1%;干旱胁迫主要影响了文冠果地上部干物质的累积,与对照相比,13%和18%水分条件下地上干重分别降低了31%和16%,但根系干重分别是对照的95%和109%。文冠果是一种较为耐旱的树种,但是文冠果栽培过程中要及时补水才能保证树体正常生长。

With the absolute soil water content controlled in different levels, a pot experiment was conducted to study the effects of water stress on physiological mechanism in Shinyleaf Yellowhorn （Xanthoceras sorbifolia Bunge ） seedling. The results showed that, under 13 % and 18% of absolute soil water content, the stress level of the branchs reached moderate stress and mild water stress, while the membrane permeability of leaf cell was 16% and 4% higher tnan that in the control; the content of soluble sugars was 2.3 and 1.2 times of that in the control, and the proline con- tent increased by 2l % and 8 % compared to that of the control ; the activity of SOD decreased slightly, 5 % and 3 % low- er than in the control respectively, but the activity of CAT decreased greatly, 83 % and 68 % lower than in the control re- spectively ; the content of MDA incresed by 44 % and 1% over that of the control. Water stress had serious negative in- fluence on the accumulation of the dry mass of shoot in Shinyleaf Yellowhorn seedling, and compared with the control, the dry weight decresed by 69 % and 84 % respectively; the dry weight of root decreased appreciably, by 95 % and 109 % compared with the control. It is concluded that Shinyleaf Yellowhorn has dought resistance to a certain extent, but it needs timely irrigation during the cultivation to ensure ecnomic output.