不同基因型早稻秋种的生态适应性

The ecological adaptability of different early rice genotype to autumn cultivation

１２ 个生育期相近的早稻中的早熟和早中熟水稻品种在１９９６～１９９７ 年７ 月２１ 日至８ 月５ 日每５ 天一次的分期直播试验中生育特征表现出了广泛的差异。根据各品种在４ 个不同播期中的生育与产量表现及所需的有效积温及营养期与全生育期的有效积温比， 可将参试品种分为“强温敏型、灌浆促进型和灌浆迟滞型”三类， 其中灌浆促进型是最适合秋涝减灾的翻秋品种， 它具有当播期推迟时， 全生育期所需的有效积温减少、营养期与全生育期的有效积温比逐渐升高、灌浆期所需的有效积温迅速减少、丰产性与早熟性关系协调等特点。根据各品种随播期推迟而产量迅速下降的特点， 认为即使最适宜的早稻品种翻秋直播最迟不应超过７ 月底。

A great diversity of maturity character 12 early rice varieties sown at an interval of five days from 21 July to 5 August in 1996 and 1997 showed all varieties could be divided into three groups based on the accumulated temperature above 12℃ and the accumulated temperature ratio of vegetative stage to total growth period(ESHGP/ESHVS),namely,high temperature sensitive group,grain filling promotion group and grain filling tardy group.The group of grain filling promotion,which has less accumulated temperature within the whole growth period,gradually increasing ratio of ESHGP/ESHVS and well balanced relation between short growth period and high grain yield when the sowing date is getting later in autumn,is well suitable for compensating the loss of grain yield in rice caused by flooding.All early rice varieties even the most suitable as late rice can not be sowed later than 31 July due to the less grain yield.