干旱胁迫对宁夏枸杞叶片蔗糖代谢及光合特性的影响

Sugar Metabolism and Photosynthetic Characteristics in Leaf of Lycium barbarum L. under Drought Stress

以宁夏枸杞品种‘宁杞1号’为材料,采用防雨棚内盆栽控水法研究了轻度干旱(LD)、中度干旱(MD)、重度干旱(SD)和正常灌水(CK)4种土壤水分条件下枸杞叶片糖分含量、蔗糖代谢酶活性和光合参数的响应规律,为宁夏枸杞在干旱地区高产栽培提供参考依据。结果显示:(1)干旱胁迫降低了枸杞青果期叶片蔗糖和淀粉含量,轻度干旱胁迫可提高枸杞色变期叶片果糖和蔗糖含量,而成熟期叶片淀粉含量则随着干旱加重而升高。(2)干旱胁迫降低了青果期枸杞叶片中性转化酶(NI)、蔗糖磷酸合成酶(SPS)和蔗糖合成酶(SS)的活性,降低了色变期和成熟期叶片酸性转化酶(AI)和SS的活性,但提高了色变期和成熟期叶片NI的活性。(3)随着干旱胁迫的加剧,叶片净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gs)呈降低趋势,瞬时水分利用率(WUE)呈现:LD>CK>SD>MD的变化趋势。研究认为,轻度干旱胁迫能促进宁夏枸杞成熟期叶片蔗糖积累和水分利用率提高,有利于更多光合同化物输送到果实中。

A study of the response of sugar ic parameters in leaf of Lycium barbarum yield planting of this plant in the arid regi in leaves were reduced under water stress drought at the color fruit stage. The starc content, enzyme activities of sugar metabolism and photosynthet under water stress aimed at providing theoretical basis for highons. The results showed that： （1）The sucrose and starch contents at the green fruit stage,but their contents increased under light h content in leaves gradually increased with drought aggravated. （2）The activities of neutral invertase（NI）,sucrose phosphate synthase （SPS） and sucrose synthase （SS） in leaves were gradually reduced under drought stress at the green fruit stage. The activities of acid invertase （AI） and SS were reduced at the color fruit and maturing stages,but the activities of NI was increased at these two stages. （3）With the increasing of drought stress,the leaf net photosynthetic rate （P.） ,transpira tion rate （Tr） and stomatal conductance （Gs） were gradually lowering. The water use efficiency （WUE）was light drought （LD）normal irrigation （CK）severe drought （SD）moderate drought （MD）. It is therefore suggested that light drought can promote the sucrose content and WUE in leaf and transport more photoassimilates to the fruit.