孕穗期渍水对小麦花后根系形态、抗氧化酶活性及籽粒产量的影响

Effects of waterlogging at booting stage on post-flowering root morphology,antioxidant enzyme activity and grain yield of wheat

为明确孕穗期土壤渍水对花后不同土层小麦生长发育和产量的影响,本研究以扬麦18和烟农19为供试品种,采用管栽方式,在小麦孕穗期进行渍水5 d、10 d和15 d处理,以无渍水处理为对照(CK),分析孕穗期不同渍水持续时间对花后不同土层小麦根系形态、抗氧化酶活性和产量及构成要素的影响。结果表明:孕穗期渍水能显著影响小麦花后根系形态、抗氧化酶活性和产量。随孕穗期渍水持续时间的延长,花后6 d和18 d,不同土层小麦根系累计根长、累计根表面积、累计根体积及根平均直径均呈减少趋势;各渍水持续时间处理下,根系累计根长、累计根表面积、累计根体积、根平均直径与CK的相对值变化不大。随孕穗期渍水持续时间的延长,花后18 d不同土层根系超氧化物歧化酶(SOD)活性和过氧化物酶(POD)活性都呈减少趋势,而丙二醛(MDA)含量呈增加趋势;小麦成熟期茎叶的干物质分配指数呈增加趋势,而籽粒的干物质分配指数呈减少趋势。孕穗期渍水通过影响穗粒数及千粒质量使籽粒产量降低。花后18 d 20.1~60.0 cm土层的累计根长、累计根表面积、累计根体积及根系SOD活性、POD活性、MDA含量及产量之间的相关性极显著。

To clarify the effects of soil waterlogging during the booting stage on the growth and development of wheat root in different soil layers after flowering and yield,this study used Yangmai 18 and Yannong 19 as test varieties,and used tube planting to treat wheat with waterlogging for 5 d,10 d,and 15 d during the booting stage.The non-waterlogging treatment was used as a control(CK)to analyze the effects of different waterlogging durations during the booting stage on the root morphology and antioxidant enzyme activity in different soil layers after flowering,yield and its components of wheat.The results showed that waterlogging during the booting stage could significantly affect the root morphology,antioxidant enzyme activity after flowering,and yield of wheat.With the prolongation of waterlogging duration during the booting stage,the cumulative root length,cumulative root surface area,cumulative root volume,and average root diameter of wheat roots in different soil layers showed a decreasing trend at 6 d and 18 d after flowering.Under different waterlogging durations,the relative values of cumulative root length,cumulative root surface area,cumulative root volume,average root diameter to those of CK had no significant change.With the prolongation of waterlogging duration during the booting stage,the activities of superoxide dismutase(SOD)and peroxidase(POD)in roots at 18 days after flowering in different soil layers showed a decreasing trend,while the content of malondialdehyde(MDA)showed an increasing trend.The dry matter partition index of stems and leaves during the mature stage of wheat showed an increasing trend,while the dry matter partition index of grains showed a decreasing trend.Waterlogging during the booting stage reduced grain yield by affecting kernel number per spike and 1000-grain weight.The cumulative root length,cumulative root surface area,cumulative root volume,root SOD activity,POD activity and MDA content at 18 days after flowering in 20.1-60.0 cm soil layer were significantly correlated with yield.