摘叶对不同株型木薯品种源、库器官特征的影响

Effects of Leaf-Picking on Characteristics of Source and Sink Organs of Cassava Cultivars with Different Plant Types

为明确摘叶对不同株型木薯品种源、库器官特征的影响,以紧凑型品种‘华南205’‘、桂热4号’和伞型品种‘华南12号’、‘华南15号’为试验材料,设计4个摘叶处理和不摘叶处理,研究木薯植株形态、干物质生产、氮素积累量和叶片营养物质的差异。结果表明,随着源叶数的减少,单株块根产量、成熟期植株的干物质量和氮素积累量随之降低。植株保留的源叶数越少,摘叶比越大,库/源比越小,株高变矮,茎秆和薯粗变细,薯长变短。随着源叶数的增多,叶片可溶性总糖含量随之呈增加的趋势,叶片蔗糖和总淀粉含量随之呈先增后降的趋势。随着摘叶时间的递进,叶片可溶性总糖和总淀粉含量随之增加,而蔗糖含量随之下降。紧凑型品种叶片可溶性总糖、蔗糖和总淀粉含量均高于伞型品种。研究发现,木薯植株保留的源叶数过少,摘叶比大,植株干物质量和氮素积累量降低,植株和块根的生长受限,块根产量下降。研究以期为高纬度区域木薯高产栽培提供理论支撑。

The experiment aims to clarify the effects of leaf-picking on the characteristics of the source and sink organs of cassava cultivars with different plant types.Using compact cultivars of'SC205','GR4'and umbrella cultivars of'SC12','SC15'as experiment materials,four leaf-picking treatments and non leaf-picking treatment were designed to study the differences in plant morphology,dry matter production,nitrogen accumulation and leaf nutrient quality.The results showed that with the number of source leaves decreased,the tuber yield per plant,dry matter production and nitrogen accumulation of mature plants decreased.The lower the number of source leaves in plant,the greater the leaf-picking ratio,the smaller the sink source ratio,the shorter the plant height,the thinner the stem diameter and the tuber diameter,and the shorter the tuber length.As the number of source leaves increased,the soluble total sugar content in the leaves showed an increasing trend,while the sucrose and total starch content in the leaves first increased and then decreased.As the leaf-picking stage progresses,the soluble total sugar and total starch content of the leaves increased,while the sucrose content decreased.Among different plant types,the content of soluble total sugar,sucrose and total starch in the leaves of compact cultivars was higher than that of umbrella cultivars.The number of source leaves retained by cassava plants is too small,the leaf removal ratio is large,resulting in a decrease in plant dry matter quality and nitrogen accumulation,the growth of plants and tubers will be restricted,and the yield of tubers will be decreased.