宁夏中部干旱带不同水分条件下苜蓿碳同位素分辨率与光合同化特征的关系  

Relationship between carbon isotope discrimination and photosynthetic assimilation feature for Medicago sativa grown under three water treatments in Ningxia Central Area

作　　者：朱林[1,2] 田忠 祁亚淑 许兴[1,2] 

机构地区：[1]宁夏大学西北土地退化与生态恢复国家重点实验室培育基地,宁夏银川750021 [2]宁夏大学西北退化生态系统恢复与重建教育部重点实验室,宁夏银川750021 [3]宁夏国营简泉农场,宁夏石嘴山75300 [4]宁夏大学农学院,宁夏银川750021

出　　处：《农业科学研究》2016年第3期1-10,共10页Journal of Agricultural Sciences

基　　金：国家自然科学基金项目(NGY2015030);宁夏回族自治区牧草育种专项(2014NYYZ0401)

摘　　要：研究了10个品种紫花苜蓿(Medicago sativa)在宁夏中部半干旱区3种灌溉条件下叶片Δ^(13)C、整株Δ^(13)C及叶片可溶性糖Δ^(13)C与各组分碳含量及光合气体交换参数的关系.结果表明:水分处理显著影响不同茬次各组分碳同位素分辨率(Δ^(13)C),且叶片可溶性糖Δ^(13)C在不同水分处理条件下的差异显著性大于叶片Δ^(13)C及整株Δ^(13)C.第1茬和第2茬叶片Δ^(13)C及可溶性糖Δ^(13)C与碳含量呈显著负相关.在第2茬,叶片及可溶性糖Δ^(13)C与蒸腾速率、气孔导度显著正相关、与叶片温度及瞬间水分利用效率(WUE)呈显著负相关.第1茬叶片可溶性糖Δ^(13)C、第3茬叶片Δ^(13)C与Ci/Ca(胞间CO2浓度/空气中CO2浓度)呈显著正相关.以上结果说明苜蓿叶片Δ^(13)C、可溶性糖Δ^(13)C以及整株Δ^(13)C较好地反映了植株水分状况,尤其是叶片可溶性糖Δ^(13)C与光合产物的合成与转运有密切的关系,在苜蓿高WUE品种筛选中有较好的应用价值.Relationship of carbon isotope discrimination （ △^13C） with carbon content in leaf, whole plant and leaf soluble sugar and leaf gas exchange parameters of Medicago sativa grown under three irrigation conditions in Ningxia Central Semi-arid region were studied. The results showed that water treatment significantly affected different fractions △^13C for Medicago sativa in three cuttings, with leaf soluble sugar △^13C being higher than leaf and whole plant △^13C. There were significant and negative correlations between △^13C and carbon content in leaf and leaf soluble sugar before first and second cuttings. In second cutting, leaf △^13C and leaf soluble sugar △^13C significantly and positively correlated with transpiration speed and stomatal conductance, and negatively with leaf temperature and leaf intrinsic water use efficiency （WUE） in second cutting. There were significant and positive correlations between Ci/Ca （the ratio of internal leaf CO2 concentration to ambient CO2 concentration） and leaf soluble sugar △^13C in the first cutting, and leaf △^13C in the third cutting. The resuh indicated that leaf △^13C and soluble sugar △^13C of Medicago sativa reflected plant water status. Leaf soluble sugar △^13C was closely related with the assimilation and partitioning of photosynthetic product, which have potential value in selection for high WUE Medicago sativa variety in the breeding project.

关 键 词：紫花苜蓿 光合气体交换参数 碳同位素分辨率 碳含量 

分 类 号：S152.7[农业科学—土壤学]