江淮稻区不同穗型粳稻品种主要农艺和品质特性的比较分析

依据着粒密度，对江淮稻区大面积生产应用的和新近育成的36个粳稻品种(系)进行聚类分析。结果表明，供试品种可分成半密穗型(Ⅰ)、偏密穗型(Ⅱ)和密穗型（Ⅲ）三类。随着水稻品种由散穗型向半密穗型、偏密穗型和密穗型的演变，产量性状、品质性状、形态性状和部分生理、生化性状发生了明显的变化，产量、每穗总粒数和实粒数显著增加，而穗数/m²、千粒重和结实率呈下降趋势；株高增加，上部三张叶片变长、变宽，生物日产量增高；穗部一、二次枝梗数增多，着粒密度变大；抽穗期和成熟期叶片、茎秆的含氮量和叶片叶绿素含量增高；糙米率和整精米率下降、垩白粒率降低、胶稠度变硬、蛋白质含量呈上升的趋势。

Comparison on Main Agronomical and Quality Characters between Japonica Cultivars with Different Panicle Types in Jiang-Huai Area

Thirty six japonica cultivars bred in Jiang-Huai area were categorized into three groups with semi-dense panicle,(near-dense) panicle and dense panicle by clustering analysis,based on panicle grain density.With the panicle type changing from thin panicle to semi-dense panicle and dense panicle the rice cultivars were changed as follows: total grain numbers and filled grain numbers per panicle,the diurnal yield were improved significantly while panicle numbers/m~2,1000-grain-weight and the percentage of filled grains declined;plant height increased,top three leaves became longer and wider,biological production per day increased;the first and second branches of the panicle and grain density increased;some values of physiological character increased,such as nitrogen content and chlorophyll content of leaf,and nitrogen content of stem during heading and maturity stages.As to some grain quality characters,the rate of brown rice and head milled rice,chalkiness rate decreased,gel consistency became rigid and protein content was increased.