半干旱地区春小麦根系形态特征与生长冗余的初步研究

以半干旱地区6个不同年代春小麦品种为材料,对各品种苗期种子根系的数量、形态特征进行了比较研究,分析了这些指标与作物抗旱高产的关系。结果表明,黄土高原半干旱地区春小麦品种在根系生长上存在着对产量不利的冗余。在以提高产量潜力为宗旨的品种更新替代过程中,不同年代春小麦品种随着年代推进逐渐呈现出根条数和根长减小、根活性吸收面积比增加、种子根中央大导管直径减小的趋势。这些特点使得现代春小麦品种在早期营养生长过程中能够节约用水而保留一定土壤水分以满足花期和灌浆期水分需求,因而提高了作物产量。

Morphological characteristics and growth redundancy of spring wheat root system in semi-arid regions

Six spring wheat cultivars bred at different years in semi-arid regions were selected to comparatively study the numbers and morphological characteristics of their seminal root systems, and to analyse the relationship of these indexes with crop drought-resistance and yield production. The results show that in semi-arid regions of loess plateau, the cultivars had a growth redundancy of root systems, which was unfavourable to the yield production. With the lapse of breeding years, the cultivars tended to have less root, shorter root length, larger active root absorption area, and smaller diameter of metaxylem vessel of seminal roots. These features made the cultivars bred at recent years use water more savingly at their earlier vegetative growth period, and conserve certain amount of soil water to satisfy their water needs at flowering and seed-filling stages, and hence, enhance their yield production.