Salt stress is one of the worldwide abiotic stresses resulting in growth re- duction, chlorosis, wilting, and plant death. These exhibitions might result from men- tal toxicity and osmotic stress induced by salt. The ...Salt stress is one of the worldwide abiotic stresses resulting in growth re- duction, chlorosis, wilting, and plant death. These exhibitions might result from men- tal toxicity and osmotic stress induced by salt. The two aspects of stress would af- fect vital metabolic pathways, reactive oxygen species scavenging system, lipid per- oxidation and photosynthetic apparatus. Thus, exploring ways to improve crop pro- ductivity or alleviate harmful effects under salt is one of the major areas of concern. Polyamines are aliphatic nitrogen organic cations which are implicated in a wide range of plant physiological processes such as morphogenesis, flower differentiation and initiation, they also play a role in biotic or abiotic stress responses. At the physiological level, polyamines modify the activities of many enzymes included in salt stress response and can bond to photosynthetic apparatus, thus changing the photosynthetic efficiency. At molecular level, polyamines can modify expressions of the polyamine-related genes directly or indirectly. Significant researches had been done to understand the effects of polyamines on plant salt resistance, but several questions still need to be answered. The present review is focused specifically on the effects of polyamines on physiological and molecular changes in plants under salt stress.展开更多
以杂交稻 F 优498为材料，研究了高、低土壤肥力下麦秆覆盖与氮肥运筹对杂交稻主要生育期氮素吸收利用特征、产量及米质的影响，并探讨了不同土壤肥力下麦秆覆盖和氮肥运筹对结实期剑叶 SPAD 值与稻米品质的形成的影响.结果表明，不同...以杂交稻 F 优498为材料，研究了高、低土壤肥力下麦秆覆盖与氮肥运筹对杂交稻主要生育期氮素吸收利用特征、产量及米质的影响，并探讨了不同土壤肥力下麦秆覆盖和氮肥运筹对结实期剑叶 SPAD 值与稻米品质的形成的影响.结果表明，不同土壤肥力下，麦秆覆盖均有效促进杂交稻各生育时期氮素积累，提高了氮素利用效率以及稻谷产量，增加了稻米蛋白质含量、稻米胶稠度，显著降低了稻米垩白度以及垩白粒率，且高土壤肥力下麦秆覆盖优于低土壤肥力下麦秆覆盖处理.同时，不同土壤肥力下麦秆覆盖处理，均以 m 基肥∶m 蘖肥∶m 穗肥为3∶3∶4的氮肥运筹模式最优，均能有效调节水稻灌浆结实期叶片 SPAD 值，提高水稻氮素吸收利用效率及稻谷产量；但稻米品质方面，高土壤肥力以 m 基肥∶m 蘖肥∶m 穗肥为5∶3∶2时最佳；而低土壤肥力可适当提高氮肥后移比例，以 m 基肥∶m 蘖肥∶m 穗肥＝3∶3∶4最佳.相关分析表明，水稻灌浆期剑叶 SPAD 值与稻米出糙率、整精米率以及蛋白质含量显著或极显著正相关（r ＝0．47？～0．90？？）；与垩百度、垩白粒率负相关，但相关未达显著水平；而高土壤肥力下稻米品质各项指标分别与齐穗后19～27 d 剑叶 SPAD 值，低土壤肥力下麦秆覆盖与齐穗后13～19 d 剑叶 SPAD 值相关系数最大.展开更多
基金Supported by the National Natural Science Foundation of China(31101117)National Key Technology Research and Development Program of China during the 12th Five-year Plan Period(2011BAD16B05,2012BAD04B13,2013BAD07B13)Rice Breeding Project in Sichuan Province of China(2011NZ0098-15)~~
文摘Salt stress is one of the worldwide abiotic stresses resulting in growth re- duction, chlorosis, wilting, and plant death. These exhibitions might result from men- tal toxicity and osmotic stress induced by salt. The two aspects of stress would af- fect vital metabolic pathways, reactive oxygen species scavenging system, lipid per- oxidation and photosynthetic apparatus. Thus, exploring ways to improve crop pro- ductivity or alleviate harmful effects under salt is one of the major areas of concern. Polyamines are aliphatic nitrogen organic cations which are implicated in a wide range of plant physiological processes such as morphogenesis, flower differentiation and initiation, they also play a role in biotic or abiotic stress responses. At the physiological level, polyamines modify the activities of many enzymes included in salt stress response and can bond to photosynthetic apparatus, thus changing the photosynthetic efficiency. At molecular level, polyamines can modify expressions of the polyamine-related genes directly or indirectly. Significant researches had been done to understand the effects of polyamines on plant salt resistance, but several questions still need to be answered. The present review is focused specifically on the effects of polyamines on physiological and molecular changes in plants under salt stress.
文摘以杂交稻 F 优498为材料，研究了高、低土壤肥力下麦秆覆盖与氮肥运筹对杂交稻主要生育期氮素吸收利用特征、产量及米质的影响，并探讨了不同土壤肥力下麦秆覆盖和氮肥运筹对结实期剑叶 SPAD 值与稻米品质的形成的影响.结果表明，不同土壤肥力下，麦秆覆盖均有效促进杂交稻各生育时期氮素积累，提高了氮素利用效率以及稻谷产量，增加了稻米蛋白质含量、稻米胶稠度，显著降低了稻米垩白度以及垩白粒率，且高土壤肥力下麦秆覆盖优于低土壤肥力下麦秆覆盖处理.同时，不同土壤肥力下麦秆覆盖处理，均以 m 基肥∶m 蘖肥∶m 穗肥为3∶3∶4的氮肥运筹模式最优，均能有效调节水稻灌浆结实期叶片 SPAD 值，提高水稻氮素吸收利用效率及稻谷产量；但稻米品质方面，高土壤肥力以 m 基肥∶m 蘖肥∶m 穗肥为5∶3∶2时最佳；而低土壤肥力可适当提高氮肥后移比例，以 m 基肥∶m 蘖肥∶m 穗肥＝3∶3∶4最佳.相关分析表明，水稻灌浆期剑叶 SPAD 值与稻米出糙率、整精米率以及蛋白质含量显著或极显著正相关（r ＝0．47？～0．90？？）；与垩百度、垩白粒率负相关，但相关未达显著水平；而高土壤肥力下稻米品质各项指标分别与齐穗后19～27 d 剑叶 SPAD 值，低土壤肥力下麦秆覆盖与齐穗后13～19 d 剑叶 SPAD 值相关系数最大.
