有序摆抛栽超高产栽培对水稻根系形态生理特征的影响

为研究不同抛栽方式对水稻根系形态生理的影响,探索抛秧稻超高产轻简栽培新途径,以粳型超级稻武运粳24和南粳44为试验材料,设置摆栽、点抛和撒抛三种抛栽方式,并以机插为对照,系统研究了有序摆抛稻根系的形态和生理特征。结果显示,水稻有序摆栽和点抛后秧苗根系长度、根数、单株根质量高于撒抛和机插,栽后7 d 3连孔稻苗优势明显,栽后15d2连孔秧苗表现出较强的优势。各生育时期群体根干质量、根冠比、根系活力表现为摆栽点抛撒抛机插,不同连孔稻株间表现为2连孔3连孔单孔,根系吸收总面积、活跃吸收表面积和吸收面积比与穗后根系伤流量亦呈现相同趋势。各生育时期的根系干质量、根冠比、根系活力及抽穗期单茎根系伤流量、根系吸收表面积、活跃吸收表面积、活跃吸收比与产量极显著相关。齐穗后15d,70%以上根系分布在0~5cm,90%以上根系分布在0~10cm,各层根干质量、根体积、根干质量密度抛栽方式间表现为摆栽点抛撒抛,不同连孔处理间为2连孔3连孔单孔,5~10cm、10~15cm、15~20cm的根系比例亦呈现此趋势。0~20cm内,各层根系干质量、根系体积、根干质量密度与产量极显著相关,上层根系对产量贡献较大,0~10cm贡献率达90%以上。总之,水稻有序摆抛栽根系发生快,各生育期活力强,后期分布合理,其良好的根系特性是超高产形成的生理基础。

Effect of Ordered Transplanting and Optimized Broadcasting on Rice Root System Morphological and Physiological Characteristics Under Super High yielding Cultivation

The rice root system morphological and physiological characteristics were to explore the approaches to achieve super high yield. Super rice Wuyunjing 24 and Nanjing 44 were used as experimental material and three planting methods including ordered transplanting (OT), optimized broadcasting (OB) and cast transplanting(CT) were designed to investigate the root system morphological and physiological characteristics with mechanical transplanting(MT) as control. The results were as follows: root length, number and weight of 3 hole seedlings had obvious advantages 7 d after transplanting and 2 hole seedlings had obvious advantages 15 d after transplanting. Root dry weight, root shoot ratio and activity of root system at each stage followed the trend of OT>OB>CT>MT, while treatments of different holes showed a trend of 2 hole>3 hole>1 hole. And total root absorbing surface area, active absorbing area, ratio of active absorbing surface area to total absorbing surface area and root bleeding sap showed the same trend. Root dry weight, root shoot ratio, root activity, total absorbing surface area, active absorbing area, ratio of active absorbing surface area to total absorbing surface area and root bleeding sap had a very significant positive correlation with grain yield. Root at the depth of top 5 cm accounted for more than 70%， while at depth of top 10 cm accounted for more than 90%. And root dry weight, root volume and root weight density at each layer showed the trend of OT>OB>CT, 2 hole>3 hole >1 hole. Root weight ratio at the depth of 5-10 cm, 10-15 cm and 15-20 cm showed the same trend. And root dry weight at each layer was very significantly correlated with grain yield, and root at the upper layer made greater contributions to the grain yield, and the contribution rate of root to yield at the top 10 cm depth was more than 90%. And it could be concluded that, ordered transplanting and optimized broadcasting rice with 2 hole seedling had quicker root growth, higher root activities and more reasonable root distribution at late growing stage which were the physiological basis for super high yield.