中文摘要：

通过设置带土直立苗、带土倾斜苗、带土平躺苗、无土平躺苗、无土直立苗等不同苗姿,研究了抛秧稻的根系生长特点及其对水稻生长的影响。带土直立苗、带土倾斜苗抛秧活棵立苗快,在根系长度、根系干质量、黄根比方面都优于带土平躺苗和无土平躺苗,后者的立苗速度和根系生长极显著线性相关。秧苗活棵立苗后,带土直立苗、带土倾斜苗分蘖发生迅速且成穗率高,后期有着较强的根系活性,各生育时期保持适宜的根冠比,植株的吸氮速率、叶片的叶绿素含量、根系下扎深度都显著高于带土平躺苗和无土平躺苗。带土直立苗、带土倾斜苗活棵立苗快,其根系生长显著优于带土平躺苗和无土平躺苗,并在各生育时期保持较强的生长势。因此,提高带土直立苗比率、减少平躺苗比率和通过促进根系生长来促进抛秧立苗,进而促进抛秧稻高产、超高产。

英文摘要：

The root growth characteristics of broadcasted rice seedlings and the effects of broadcasting on plant growth were systematically studied under the treatments of upright seedlings with soil（USWS）,leaning seedlings with soil（LESWS）,lying seedlings with soil（LASWS）,leaning seedlings without soil（LASWTS） and upright seedlings without soil（USWTS）.USWS and LESWS recovered earlier with a smaller dead root ratio,and the length and the dry weight of roots were both higher than those of LASWS and LESWTS whose seedling standing speed was extremely and significantly correlated with the root growth.USWS and LESWS,characterized by earlier tillering and higher productive tiller rates,maintained stronger root activity at later stages and optimum root-shoot ratio throughout the whole growth period,displaying significantly higher nitrogen Absorption rates,leaf chlorophyll content and root depths than LASWS and LASWTS.Considering earlier standing and recovery,significantly better root growth and fairly stronger growth capacity of USWS and LESWS,it is reasonable to seek high yielding and super high yielding of broadcasted rice by means of increasing the rate of upright seedlings with soil,reducing lying seedlings and improving seedling standing by promoting root growth.