摘要
以耐阴性中等的杂交稻川香9838为材料,研究不同播期和抽穗期弱光胁迫对杂交稻抽穗期光合特征、渗透调节物质、保护性酶活性和产量的影响.结果表明:不同播期和抽穗期弱光胁迫对水稻抽穗期干物质积累、剑叶光合速率、抗氧化酶活性和产量均有显著影响.随播期的推迟,全生育期明显缩短,稻谷产量呈不同程度的下降趋势.与对照相比,抽穗期轻度弱光胁迫(遮光20%)能缓解水稻生育过程中面临的高温及强光照危害,进而能缓解剑叶光合速率和抽穗期干物质累积的降低,调节抗氧化酶活性,适度提高结实率;而抽穗期中度(遮光40%)、重度(遮光60%)弱光胁迫均不利于水稻生长.剑叶光合速率、丙二醛含量和超氧化物歧化酶活性对播期和抽穗期弱光胁迫较为敏感.水稻始穗1～5d剑叶光合速率与稻谷产量和抽穗后干物质积累量显著相关.
Hybrid rice Chuanxiang 9838 with medium shade-endurance was taken as the test material to investigate the effects of different sowing dates and low-light stress at heading stage on the flag leaf photosynthetic rate （Pn）,osmotic regulators,antioxidant enzyme activities and the grain yield of hybrid rice.Sowing date and low-light stress at heading stage had significant effects on the flag leaf Pn and antioxidant enzyme activities and plant dry matter accumulation at heading stage and the grain yield.With the delay of sowing date,the whole period of rice growth and development shortened notably,and the grain yield decreased to different degrees.Compared with the control,short-term slight low-light stress （20% shading） at heading stage could relieve the harms from high temperature and strong light,and further,relieve the decrease of flag leaf Pn and plant dry matter accumulation at heading stage,adjust the flag leaf antioxidant enzyme activities,and moderately improve the seed setting rate.However,short-term medium low-light stress （40% shading） and serious low-light stress （60% shading） were not beneficial to the rice growth.Correlation analysis indicated that the flag leaf Pn,malondialdehyde （MDA） content,and superoxide dismutase （SOD） were more sensitive to the sowing date and low-light stress at heading stage,and there existed a highly significant positive correlation between the flag leaf Pn at initial heading stage （1-5 d） and the plant dry matter accumulation at late heading stage and grain yield.
出处
《应用生态学报》
CAS
CSCD
北大核心
2012年第10期2737-2744,共8页
Chinese Journal of Applied Ecology
基金
中国气象局西南区域气象中心2010年区域重大项目(2010-7)
国家粮食丰产科技工程项目(2011BAD16B05,2012BAD04B13)
四川省教育厅资助科研项目(10ZA047)
四川省育种攻关专项(2006yzgg-28)资助
关键词
水稻
播期
弱光胁迫
光合速率
产量
rice
sowing date
low-light stress
photosynthetic rate
yield.
