行距对两个不同类型水稻品种冠层结构与产量的影响

摘要

以寒地粳稻龙粳20(多蘖弯穗型)和龙粳21(少蘖半直立穗型)为试材,研究了行距对两个不同类型水稻配品种冠层结构、形态和产量的影响.结果表明,行距与两种类型水稻成穗率呈先降后升的二次回归关系,与分蘖末期叶面积指数和单位面积最大茎蘖数认先升后降的二次回归关系.行距对龙粳20一次枝粳的影响大大于二次枝粳,而龙粳21则相反;行距与参试品种的二次枝梗结实率和穗结实率均呈负相关,其中与龙粳20二次枝梗结实率呈极显著负相关.行距与龙粳20产量呈正相关.但相关不显著,与龙粳21的产量呈极显负相关.多蘖弯穗型品种的株型性状更易受到行距的影响,其中行距与龙粳20的剑叶长、剑叶宽、倒1节间长、倒2节间长和穗长均呈显著或极显著正相关,而与龙粳21的各株型性桩相关均不显著.较宽行距有利于多蘖弯穗型品种穗、茎、叶干物质积累和产量的形成.龙粳20的最佳行距处理为30 cm,而少蘖-半直立穗型品种龙粳21,窄行距更佳,最佳行距为21cm.分析认为宽行距移栽有利于改善多蘖-弯穗型品种的群体生态环境,窄行距有利于提高少蘖-半直立虽型品种的空间利用.%Two cold region japonica rice varieties Longjing 20 (more tillers and curved panicle type. MCP) and Longjing 21 (few tillers and half-erect panicle type, FKP) were used as materials to study the effect of row-spacing on canopy structure, morphological traits and yield. The productive tiller percentage reduced first and then increased as row-spacing widened and followed a quadratic regression. Leaf area index (LAI) at later tillering stage and the highest stem numher per unit area followed a quadratic regression, increasing first and then reducing. The effect of row-spacing on primary rachis branch was larger than on secondary rachis branch in Longjing 20 and the trend of Longjing 21 was reverse. The row-spacing showed a negative correlation with seed setting rates of secondary rachis branch and panicle. The correlation between row-spacing and yields of Longjing 20 and Longjing 21 was positive and significantly negative, respectively. The morphological traits of MCP were more easily affected by row spacing and the row-spacing showed positive correlation with flag leaf length, flag leaf width, the 1st in-ternode length from the top, the 2nd internode length from the top and panicle length. Otherwise,the morphological traits of FKP were not significantly affected by row-spacing. The wide row-spacing was propitious to accumulate dry matter of panicle, stem and leaf and to form yield in MCP (the best row-spacing of Longjing 20 was 30 cm), the narrow row-spacing was suit to Longjing 21 which has few tillers and half erect panicle (the best row-spacing of Longjing 21 was 21 cm). It was suggested that wide row spacing was benefitial to improving population environment of MCP and narrow row-spacing was favorable to increase space utilization of FKP.