水分胁迫对线辣椒叶片渗透调节作用的影响

以线辣椒"2号"、"6号"、"L14"品系为材料,采用盆栽方法,于定植20 d(缓苗结束)后进行5个水分梯度的干旱胁迫处理,即土壤相对含水量分别为45%、55%、65%、75%、85%(CK),于处理20天后的开花坐果期间测定不同水分胁迫下叶片的脯氨酸含量、可溶性糖含量及细胞膜相对透性,分析土壤相对含水量对线辣椒叶片渗透调节物质的影响。结果表明,随着水分胁迫程度的加重,3个品系叶片内细胞膜相对透性、脯氨酸含量、可溶性糖含量均逐步上升,在土壤相对含水量为45%的处理下,2号、6号、L14的细胞膜透性分别为对照的1.38、1.47和1.35倍,脯氨酸含量分别为对照的2.00、1.47和2.00倍,可溶性糖含量分别为对照的1.67、1.35和3.70倍。说明线辣椒可以通过渗透调节作用来适应干旱逆境。L14在水分胁迫下细胞膜的结构和功能遭到破坏的程度较低,渗透调节和耐旱能力较强;6号品系对外界环境变化的适应与抵御能力相对较弱,2号品系居中。

Effects of water stress on osmosis-adjusting substances in leaves of line pepper

The line pepper No.2, L14 and No.6 were used as materials. Under the potted planting, an experiment was carried out with 5 water treatments, i.e. the relative soil water content of treatments was 45 %, 55 %, 65 %, 75 % and 85 % (CK) of field capacity respectively. The free praline, soluble sugar and cell membrane permeability were de-termined 20 days after fix planting, and the effect of water stress on osmosis- adjusting substances was analyzed in line pepper. The results showed that the cell membrane permeability, proline content and soluble sugar content of leaves were gradually increased as the sevenity of water stress increasing. In the soil relative water content of 45%, the cell mem-brane permeability of No.2, No.6 and L14 was 1.38, 1.47 and 1.35 times of control ( soil relative water content 85 %), respectively. The proline content was 2.00, 1 .47 and 2.00 times of control, and the soluble sugar content was 1.67, 1.35, and 3.70 times of control . These indicate that the line pepper can regulate the osmosis- adjusting substances to adapt to water stress. Under water stress, the destruction of membrane structure and function in L14 is not serious and this indicates the drought resistance of L14. The drought tolerance of No.6 is weak, while that of No .2 is middling.