摘要
【目的】通过筛选可以有效缓解甜瓜幼苗自毒胁迫的硅酸钠浓度,对不同处理条件下幼苗生长指标和叶绿素荧光参数的变化进行测定,初步明确外源硅缓解甜瓜自毒胁迫的形态学和光合基础,以期为克服甜瓜连作障碍提供有益参考。【方法】以甜瓜2叶1心幼苗为材料,利用质量浓度为0.03g·mL^-1的植株浸提液模拟自毒胁迫,分别添加不同浓度硅酸钠(0、1、2、4、8、16、32mmol·L^-1)溶液进行复合处理;通过观测幼苗生长状态,测量株高、根长、鲜重、茎粗及根系表面积等形态学指标,筛选出能有效缓解自毒胁迫的硅酸钠浓度。采用筛选出的最佳硅酸钠浓度处理自毒胁迫条件下的甜瓜幼苗,于不同取样时间点测定幼苗株高、叶面积、鲜重、地上部分干重和叶绿素荧光特征,分析这一缓解作用的形态学和光合基础。【结果】4mmol·L^-1的硅酸钠可以有效缓解甜瓜幼苗的自毒胁迫。自毒胁迫显著抑制了幼苗株高,减少了叶面积,Fv'/Fm'、Y(Ⅱ)、qP和Y(NPQ)值均表现出不同程度的下降,NPQ和Y(NO)有所升高。添加硅酸钠可以明显缓解自毒胁迫对幼苗生长的影响,Fv'/Fm'、Y(Ⅱ)、NPQ、qP、Y(NPQ)和Y(NO)等参数接近或优于对照。【结论】适当浓度的外源硅处理可以改善自毒胁迫条件下甜瓜幼苗的生长状态,在一定程度上维持叶片光合系统的稳定,进而提高甜瓜植株对自毒胁迫的抵抗能力。
【Objective】To determine the sodium silicate concentration that could effectively mitigate the autotoxicity stress,which is one of the main factors causing difficulties on continuous cropping and seriously economic loss,on melon farming.【Method】 Seedlings of Cucumis melo L.with two true leaves and one bud were used in this study.The 0.03 g·mL^-1 water extract of the plant was used to simulate the autotoxicity stress.Sodium silicate solutions at different concentrations (0,1,2,4,8,16 and 32 mmol·L^-1 ) were added as treatments to determine the effectiveness in the stress alleviation through observations on the growth,plant height,root length,fresh weight,dry weight of shoot,stem diameter,and root surface area of the seedlings.Changes on chlorophyll fluorescence parameters of the seedlings were monitored as well for the analysis.【Result】 The imposed autotoxicity significantly inhibited the increases on seedling height and leaf area.In varying degrees,the Fv'/Fm',Y (Ⅱ),qP,and Y (NPQ) of the plants decreased,while NPQ and Y (NO) increased.However,the presence of sodium silicate at 4mM effectively reduced the stress with the Fv'/Fm',Y (Ⅱ),NPQ,qP,Y (NPQ),and Y (NO) as they became closer to or better than those of control.【Conclusion】 Appropriate exogenous silicon treatment appeared to enable the melon seedlings under autotoxicity stress to grow normally with a stable photosynthetic function.
作者
樊佳茹
章丽珍
王景荣
张贝贝
Gefu Wang-Pruski
张志忠
FAN Jia-ru;ZHANG Li-zhen;WANG Jing-rong;ZHANG Bei-bei;ZHANG Zhi-zhong(Joint FAFU-Dalhousie Lab/College of Horticulture,Fujian Agriculture and Forestry University,Fuzhou,Fujian 350002,China)
出处
《福建农业学报》
CAS
CSCD
北大核心
2019年第6期638-645,共8页
Fujian Journal of Agricultural Sciences
基金
国家重大农技推广服务试点项目(KNJ-152046)
福建农林大学创新专项基金(CXZX2016018、CXZX2017168)
福建省级扶贫开发工作重点县人才支持计划专项(K1519060A)
关键词
甜瓜
硅
自毒作用
叶绿素荧光
melon ( Cucumis melo L.)
silicon
autotoxicity
chlorophyll fluorescence
