摘要
为了探明盐胁迫对油菜产量品质和生理特征的影响机制,本研究以浙油50为材料,于2020-2022年油菜生长季在盐城大丰盐碱地进行试验,分别设置低盐和高盐处理,研究油菜碳氮同化、光合特征、抗逆生理以及菜籽产量品质的变化.结果表明,相比低盐处理,高盐处理下油菜初花期各器官干物质积累降低18.46％～35.67％,成熟期降低20.92％～46.03％;高盐处理提高了初花期根和叶片的干物质分配比例,降低了茎枝的分配比例,提高了成熟期根和茎枝的分配比例,降低了果壳和籽粒的分配比例.此外,高盐处理降低初花期和成熟期各器官碳氮积累,降低了茎枝和叶片的碳氮转运效率,表明盐胁迫抑制油菜碳氮同化和花后养分转运,最终导致籽粒产量降低;另一方面,高盐处理下各器官C/N显著降低,表明盐胁迫对碳素同化的抑制程度强于氮素,导致籽粒品质改变,使籽粒蛋白质含量提高8.23％,油分含量降低4.42％.高盐较低盐显著降低初花期叶片净光合速率、气孔导度、蒸腾系数、瞬间羧化效率,提高胞间CO2浓度和水分利用效率,表明盐胁迫对油菜光合的影响可能主要归因于非气孔限制.与低盐相比,高盐下油菜H2O2和MDA含量增加27.41％和42.33％,SOD活性、CAT活性、AsA含量、可溶性蛋白含量和可溶性糖含量分别上升65.54％、22.85％、29.68％、9.75％和16.84％.由此认为,盐胁迫通过抑制油菜碳氮同化和限制光合,降低籽粒产量,改变籽粒品质,同时油菜可以提高抗氧化和渗透调节能力来适应盐胁迫环境.
Abstract
The objective of this study is to investigate the effects of salt stress on seed yield,quality,and physiological processes in rapeseed.During rapeseed growing season from 2020 to 2022,two different soil salinity levels of low soil salinity(LS)and high soil salinity(HS)were conducted for rapeseed planting in Dafeng city,Jiangsu province,China(33°24'N,120°35'E).The results indicated that,compared with LS treatment,the biomass accumulation under HS treatment was decreased by 18.46％-35.67％at the early flowering stage,and 20.92％-46.03％at maturity stage,respectively.HS treatment increased the proportion of dry biomass distribution in roots and leaves and decreased the proportion of stem and branch distribution at the early flowering stage,and increased the proportion of root,stem,and branch distribution and decreased the proportion of pod and seed distribution at maturity stage.Moreover,compared with LS treatment,HS treatment decreased the accumulations of carbon(C)and nitrogen(N)in various organs at both early flowering and maturity stages,and decreased the efficiency of C and N transloca-tion in stems,branches,and leaves at reproductive stage,indicating that salt stress inhibited C and N assimilation and transloca-tion,and ultimately led to a decrease in seed yield.Besides,C/N in all organs under HS treatment was lower than that under LS treatment,indicating that the adverse effects of salt stress on C assimilation were more intensive than those on N assimilation,which resulted in the increased seed protein content by 8.23％and decreased oil content by 4.42％.In addition,compared with LS treatment,HS treatment decreased net photosynthetic rate(Pn),stomatal conductance(Gs),transpiration rate(Tr),and instantane-ous carboxylation efficiency(CE);however,it increased intercellular CO2 concentration(Ci)and water use efficiency(WUE),which indicating that the effects of salt stress on rapeseed photosynthesis were mainly attributed to the non-stomatal factors.HS treatment increased peroxide(H2O2)and malondialdehyde(MDA)content by 27.41％and 42.33％compared with LS treatment.The superoxide(SOD)activity,catalase(CAT)activity,ascorbic acid(AsA)content,soluble protein content,and soluble sugar content under HS treatment were increased by 65.54％,22.85％,29.68％,9.75％,and 16.84％,compared with LS treatment,re-spectively.In conclusion,salt stress decreased the yield and changed quality by inhibiting C and N assimilation and photosynthe-sis in rapeseed,which could improve the antioxidants and osmotic regulation ability to adapt to salt stress environment.
基金项目
江苏省高等学校基础科学重大项目(21KJA210003)
扬州市现代农业项目(YZ2022055)
江苏省作物遗传生理重点实验室开放基金(YCSL201909)
维普
万方数据