籼粳交超级稻甬优538的穗部特征及籽粒灌浆特性

以籼粳交超级稻甬优538为试材,常规粳稻镇稻18和杂交籼稻中浙优1号为对照,将穗部分成上部一次枝粳籽粒(UP)、上部二次枝粳籽粒(US)、中部一次枝粳籽粒(MP)、中部二次枝粳籽粒(MS)、下部一次枝粳籽粒(LP)、下部二次枝粳籽粒(LS)6个部分,比较不同类型品种的穗部特征和籽粒灌浆特性。结果表明:(1)两年中甬优538平均产量为12.5 t hm–2,较中浙优1号和镇稻18分别高17.6%和15.2%;每穗粒数和群体颖花量以甬优538最高。(2)单穗重和着粒密度以甬优538最高;甬优538穗部6个部位的籽粒数均显著高于对照品种,且以上部二次枝粳籽粒和中部二次枝粳籽粒数增加最为明显。(3)甬优538中,UP与MP、MS与US、LP与LS为同步灌浆,但两两之间为异步灌浆。中浙优1号和镇稻18中,UP、US和MP为同步灌浆,而UP、US、MP与LP、LS为异步灌浆。品种类型间,穗部6个部位米粒终极生长量的平均值以镇稻18最高,最大灌浆速率和平均灌浆速率的平均值为中浙优1号镇稻18甬优538,有效灌浆时间为甬优538镇稻18中浙优1号。

Panicle Traits and Grain-filling Characteristics of Japonica/Indica Hybrid Super Rice Yongyou 538

A field experiment was conducted using indica-japonica rice Yongyou 538 as the material, conventional japonica rice Zhendao 18, and hybrid indica rice Zhongzheyou 1 as the check. The panicle was separated into six parts, i.e. upper primary branches (UP), upper secondary branches (US), middle primary branches (MP), middle secondary branches (MS), low primary branches (LP), and low secondary branches (LS). We compared the differences in panicle traits and grain-filling characteristics of different cultivars of rice types. The main results were as follows: (1) Yongyou 538 had an average yield of 12.5 t ha^-1 across two years, which was 17.6% and 15.2% higher than that of Zhongzheyou 1 and Zhendao 18, respectively, Yongyou 538 also had the highest spikelets per panicle and total spikelets among the three varieties. (2) Yongyou 538 had higher grain weight per panicle and grain density, as well as higher number of grains in the six corresponding parts of panicle compared with Zhongzheyou 1 and Zhendao 18, especially in the upper secondary branches and the middle secondary branches of panicle. (3) For Yongyou 538, grain-filling processes were synchronous types between UP and MP, US and MS, and LP and LS, but were asynchronous types between UP and MP, US and MS, and LP and LS. For Zhongzheyou 1 and Zhendao 18, grain-filling processes of UP, US, and MP were synchronous types, while asynchronous types existed between UP, US, MP and LP, LS. Among the varieties, the mean final weight of a kernel in the six parts of the panicle in Zhendao18 was the highest, mean value of maximum grain-filling rate and mean grain-filling rate showed Zhongzheyou 1>Zhendao 18>Yongyou 538, while effective grain-filling period showed Yongyou 538>Zhendao 18>Zhongzheyou 1