中熟类型甬优籼粳杂交稻组合产量优势形成及其形态生理特征

以中熟类型甬优籼粳杂交稻组合甬优2640、甬优1640为材料,常规粳稻镇稻11、武运粳30和杂交籼稻丰两优香1号、新两优6380为对照,比较各类型品种在干物质积累、穗部特征、叶片形态及茎秆特性上的差异。结果表明,甬优籼粳杂交稻两年平均产量为11.3 t/hm~2(11.1、11.4 t/hm~2),较常规粳稻和杂交籼稻分别高6.6%和13.0%;产量构成上,甬优籼粳杂交稻的每穗粒数和群体颖花量显著高于对照,有效穗数、结实率和千粒重低于对照;甬优籼粳杂交稻抽穗期、成熟期的干物质量及抽穗至成熟期的干物质积累量依次为13.4 t/hm2、21.6 t/hm~2、6.9 t/hm~2,均显著高于对照;穗部特征上,甬优籼粳杂交稻的单穗质量和着粒密度高于对照,穗长略低于杂交籼稻,近80%的籽粒集中于中上部,而常规粳稻75%的籽粒集中于中下部,杂交籼稻籽粒分布相对匀称;甬优籼粳杂交稻上3叶的叶宽和卷曲率高于对照,叶长和叶基角处于对照之间(以杂交籼稻最大),披垂度最低,上部1、3叶差异显著;株高、穗高、秆长及穗下节间占秆长的比例以杂交籼稻甬优籼粳杂交稻常规粳稻;成熟期单茎茎干质量、单茎鞘干质量及基部节间单位长度干质量以甬优籼粳杂交稻最高。中熟类型甬优籼粳杂交稻组合产量优势特征为足穗基础上,主攻大穗,并保持较高的结实率和千粒重;形态生理特征表现为籽粒集中于中上部,上3叶大小适宜,叶片内卷且直立,株高及穗下节间占秆长的比例适中,成熟期茎秆充实度好。

Yield Formation and Morphological and Physiological Characteristics of Medium-maturity Type of Yongyou Japonica/Indica Hybrid Rice

A field experiment was conducted to study the differences of dry matter accumulation, panicle traits, leaf morphology traits and culm traits in different types of rice varieties, using medium-maturity type of Yongyou japonica/indica hybrid rice(Yongyou 2640, Yongyou 11640) as the material, conventional japonica rice (Zhengdao 11, Wuyungeng 30) and hybrid indica rice(Fengliangyouxi-ang 1, Xinliangyou 6380) as the control. The results were as follows: the grain yield of Yongyou japonica/indica hybrid rice was 11.3 t/hm2, which was 6.6% and 13.0% higher than that of conventional japonica rice and hybrid indica rice, respectively. As for yield components, Yongyou japonica/indica hybrid rice had highest spikelets per panicle and total spikelets among the different type of rice varieties , but its 1 000-grain weight, seed setting rate and effective panicles were lower than CK. The dry matter of Yongyou japoni-ca/indica hybrid rice was 13.4 t/hm2 at heading stage and 21.6 t/hm2 at maturity stage (6.9 t/hm2 from heading to maturity), signifi-cantly higher than CK. In terms of panicle traits, Yongyou japonica/indica hybrids rice had the highest grain weight per panicle and grain density, but its panicle length was less than hybrid indica rice. The 80% grains of Yongyou japonica/indica hybrid rice were concentrated on the middle and upper part of the panicle, while the 75%grains of conventional japonica rice were concentrated on the middle and lower part of the panicle, and the grains of hybrid indica rice distributed relatively uniform. The leaf width and rolling rate of the top-three leaves of Yongyou japonica/indica hybrid rice were higher than CK. The top-three leaves of hybrid indica rice had medium leaf length and basic leaf angle. Drooping angle of the top-three leaves of Yongyou japonica/indica hybrid rice were lower than CK, and the differences of the top 1 leaf and top 3 leaf were significant. The plant height, panicle height, stalk length and the proportion of neck internode to stalk length showed hybrid indica rice> Yongyou japonica/indica hybrid rice>conventional japonica rice. Among the different type of rice varieties, Yongyou japonica/indica hybrid rice had the highest dry weight of stem, sheath and per unit internode at maturity stage. The yield advantage of medium-maturity type of Yongyou japonica/indica hybrid rice were character-ized by enough spikes and large spike, higher seed setting rate and 1 000 grain weight. The morphological and physiological charac-teristic of medium-maturity type of Yongyou japonica/indica hybrid rice were showed that grains concentrated on middle and upper part of panicle, appropriate size of top-three leaves, curled and upright leaves, moderate plant height, suitable ratio of neck internode to stalk length, and good fullness degree of stem at maturity stage.