机插杂交籼稻根系特性对地上部生长和产量形成的影响机制研究

Root characteristics and aerial part growth and yield formation in machine-transplanted hybrid indica rice will be studied by different nitrogen application rates experiment and transplanting depth and sowing densities experiment in mechanical transplanting hybrid indica rice with rice cultivars Qyou6 and Ⅱyou838 and different transplanted methods experiment in hybrid indica rice with same rice cultivars in shuiyang county, Guizhou province，and also differences of root characteristics and aerial part growth and yield formation between machine-transplanted rice and hand-transplanted rice will be analyzed. The relation between root characteristics and aerial part growth and yield formation in machine-transplanted hybrid indica rice will be explored. The objectives of this study are to (1) ascertain root characteristics and aerial part growth and yield formation properties in machine-transplanted hybrid indica rice, (2) elucidate mechanism of the effect of root characters of machine-transplanted hybrid indica rice on aerial part growth and yield formation in theory, (3) simulate the relation between root characteristics and aerial part growth and yield formation in machine-transplanted hybrid indica rice, (4) establish the simulation models between root characteristics and aerial part growth and yield formation in machine-transplanted hybrid indica rice. By this study, yield formation regular pattern and high-yielding mechanism would be revealed in karst mountain area, it will have import scientific and practical significance in enriching growth simulation models of rice，establishing control and decision-making of looking seedlings diagnosis for rice, developing root breeding and popularizing technology of rice mechanized transplanting.

以Q优6号和Ⅱ优838为材料，在贵州省绥阳县通过机插杂交籼稻不同施氮量试验、不同栽插深度和播种量试验及杂交籼稻不同栽插方式比较试验，研究机插籼稻的根系特性和地上部生长及产量形成，分析机插和手插稻根系特性和地上部生长和产量的差异，并着重就机插籼稻的根系特性与地上部生长和产量形成之间的关系进行探讨。本项目旨在探明在机插条件下，杂交籼稻的根系特性和地上部生长和产量形成特点，在理论上阐明机插籼稻的根系特性对地上部生长和产量形成的影响机制，模拟机插籼稻的根系特性与地上部生长和产量形成的关系，建立机插籼稻的根系特性与地上部生长和产量形成之间的模拟模型，这对于揭示喀斯特山区机插籼稻的产量形成规律和高产机理，丰富水稻生长模拟模型，制定水稻看苗诊断的调控决策，开展根系育种，推广水稻机插技术，均具有重要的科学意义和实践意义。

开展机插杂交籼稻根系特性对地上部生长和产量形成的影响机制研究，对于揭示喀斯特山区机插杂交籼稻的产量形成规律和高产机理，推广水稻机插技术具有重要的意义。. 本项目以准两优527和Q优6号为材料，开展了不同施氮量试验、不同机插深度和播种量试验及机插/手插试验，系统地研究了水稻根系特性、地上部生长特性和产量形成及二者的关系。研究表明,（1）随着施氮量的增大，根系活力，吸收表面积、活跃吸收表面积均有逐渐增大的趋势。随着施氮量的增加，水稻株高、茎蘖数、叶面积指数、总干物质重、叶绿素含量、PAR截获率、作物生长率、光合势、叶面积比率、净同化率、叶源总量值均有逐渐增大的趋势，而粒叶比逐渐降低。随着施氮量的提高，产量、有效穗数、每穗粒数均有逐渐增加的趋势，而千粒重和结实率则呈相反的趋势。（2）随着播量的增加，拔节期总根长、根长密度、比根长、根分枝数、冠根比和单蔸根干重逐渐减少；随着栽插深度的增加，拔节期单蔸根干重、根系活力、根系吸收表面积、比表面积表现为先增加后减少。.（3）在生育中期(拔节期至抽穗期)，机插稻叶面积指数、比叶面积、叶面积比率、光合势均高于手栽稻，干物质积累量、净同化率、作物生长率均低于手栽稻; 成熟期机插稻干物质积累量高于手栽稻; 全生育期内机插稻养分吸收量均低于手栽稻;机插稻有效穗数和千粒重高于手栽稻，而每穗总粒数和结实率低于手栽稻，产量与手栽稻无显著差异。（4）根系形态指标与产量、有效穗数、每穗粒数、总干物质重、总吸氮量呈正显著或极显著相关关系。根长密度、根重密度及根表面积分别与产量拟合，均以二次项方程模型的拟合度最好；根长密度、根重密度及根表面积分别与产量的模拟模型一般达显著水平；根系活力、根系总吸收面积及根系活跃吸收面积者与产量的模拟模型中，一般达显著水平。