Effect of sucrose accumulation and yield components on winter wheat flag leaf under drought or re-water during filing stage | 灌浆期干旱及复水对冬小麦旗叶蔗糖积累和产量构成的影响

chinois. 研究不同水分胁迫处理对不同小麦品种旗叶蔗糖积累及关键酶活性与产量构成的影响。在盆栽条件下，选用旱地品种长武134、长旱58及水地品种西农9871 3个小麦品种为供试材料，于开花前、后分别给予轻度（LS）、中度（MS）水分胁迫处理，研究其对小麦旗叶净光合速率、蔗糖含量、磷酸蔗糖合成酶(SPS)活性及产量构成因素的影响。花前轻度和中度胁迫后，灌浆期复水能在一定时间内使旱地品种长武134和长旱58的旗叶净光合速率、SPS活性均有不同程度的提高，胁迫程度越重，补偿效应越明显。花前轻度胁迫后灌浆期复水可使3个供试小麦品种的收获指数显著提高，长旱58、长武134和西农9871的收获指数分别较对照提高14.1%，15.3%和17.1%，且使2个旱地小麦品种的千粒质量较对照有所提高；中度胁迫下3个小麦品种的穗粒数均显著降低。灌浆期水分胁迫处理可有效地诱导旗叶SPS活性上升，提高蔗糖含量，随着水分胁迫程度的加剧，灌浆后期的净光合速率、SPS活性显著降低，且水地品种的下降幅度大于旱地品种；与对照相比，灌浆期中度胁迫使3个小麦品种的千粒质量均显著下降。灌浆期给予一定程度的水分胁迫及旱后复水，均有利于不同冬小麦品种蔗糖含量、SPS活性及产量的提高，且水分胁迫加剧时，旱地品种受水分胁迫的影响较水地品种小。

anglais. Effect of sucrose accumulation and yield components on wheat flag leaf of different drought tolerant cultivars under drought or re-water during filing stage was studied. Changhan 58, Changwu 134 and Xinong 9871 were selected as experimental materials and sucrose accumulation, and sucrose phosphate syntheses (SPS) activity and yield components were studied under different water stress conditions. Net photosynthetic rate, sucrose content and SPS activity of flag leaf of drought-tolerant variety were enhanced at different levels during re-water stage after light stress or moderate stress treatment. The stress was more severe, and the compensate effects were better. But the effects on drought-sensitive cultivar weren’t apparent during re-water period after moderate stress. Harvest Indexes were largely enhanced after re-watering under light stress, the harvest index of Changhan 58, Changwu 134 and Xinong 9871 exceeded the CK by 14.1%, 15.3%, 17.1%, respectively. Sucrose phosphate syntheses (SPS) activity and the supply of sucrose capability were enhanced largely during earlier grain filing stage, but reduced at great degree in late grain filing stage. The number of spike was mainly affected under stress accruing before flowering period and 1 000-grain weight decreased largely under moderate stress treatment during grain filing stage. Sucrose accumulation, SPS activity and yield components of different wheat cultivars were enhanced by varying degree under light stress of water before anthesis or later, and the effect of water stress on drought-sensitive cultivar was lower than that of the drought-tolerant ones.