【摘要】 以日本晴、武运粳 8号、扬稻 6号、汕优 6 3为供试材料 ,设计不施肥、基肥、分蘖肥、促花肥、保花肥等 4个不同氮肥施用时期的处理 ,研究水稻抽穗期主要根系性状对施氮时期反应的品种间差异及其对产量的影响。结果表明 :(1)不同穗型品种根系性状差异明显 ,小穗型品种在每株不定根数、每株不定根总长上具有优势 ,大穗型品种在每株根干重、每条不定根粗上表现优越 ;(2 )每株不定根数对施N时期的反应品种间表现一致 ,即施N时期越早 ,不定根发生越多。基肥和分蘖肥处理均可促进每株根干重和根总长的增加 ,品种间有相似的反应 ,但穗肥处理品种间存在显著差异。施N处理对每条不定根粗无显著影响 ;(3)穗肥处理能促进每株根干重和不定根总长的增加 ,增加的幅度大穗型品种大于小穗型品种 ,促花肥的效果更显著 ;(4)随着水稻品种穗型变大和产量水平的提高 ,影响产量的根系性状从少数根系性状逐渐增加到多个根系性状 ;(5 )促进不定根的发生 ,对水稻抽穗期根系性状的发展和产量的提高均具有重要意义 ,品种间有相同的趋势。更多还原

【Abstract】 Pot experiment was conducted to investigate the differences in response of main root traits at heading stage and grain yield of four rice varieties, Ribenqing, Wuyunjing 8, Yangdao 6 and Shanyou 63, to nitrogen application time. Nitrogen fertilizer was applied as basal and as top-dressing for tillering, spikelet-promoting and spikelet-sustaining, with no nitrogen application as control. The results showed that: (1) There were significant varietal differences of root traits among different ear-type of varieties. Small-ear type variety presented superiority in number of adventitious roots and total length of the roots per plant, while large-ear type variety had superiority in dry weight of roots per plant and diameter of per adventitious root; (2) Response of number of adventitious roots per plant to nitrogen application time was similar in four varieties,i.e. earlier application was more effective. Basal N and top-dressing significantly increased dry weight and total length of adventitious roots per plant, all varieties involved in this study showed the same tendency, while significant differences in response of that to ear fertilizer were observed among the varieties. There was no significant effect of N application time on diameter of per adventitious; (3) The positive effect of N applied during ear development on dry weight of roots & total length of the roots per plant in large-ear type variety at heading stage was greater than that in small-ear type variety, and spikelet promoting was more effective; (4) As ear-type enlarged and grain yield increased, the number of root traits affecting grain yield increased gradually; (5) Results obtained indicated that improving the development of adventitious roots per plant was important to increase root accumulation at heading stage and grain yield, and all varieties involved in this study showed the same tendency.更多还原