贵州省高原山区杂交籼稻不同产量水平群体的特征

Characterization of Populations with Different Yield Levels in Indica Hybrid Rice in Plateau Area of Guizhou Province

2011—2012年以超级杂交籼稻金优785为试材,研究贵州高原山区6个试验点的中产(9.0~10.5 t hm^(–2))、高产(10.5~12.0 t hm^(–2))、超高产(12.0~14.5 t hm^(–2))群体特征。结果表明:(1)不同产量水平群体的有效穗数差异最大,其次是穗粒数和结实率,千粒重差异最小,有效穗数与产量的直接通径系数2011年和2012年分别为0.5822和0.7304,相关系数分别为0.7771和0.8858;(2)抽穗期不同产量水平群体干物质积累量差异较小,成熟期超高产群体干物质积累量两年平均为21.9 h hm^(–2),分别比高产和中产群体提高了7.7%和15.9%,差异达显著水平;(3)抽穗期粒叶比以超高产群体最高,与高产和中产群体相比,超高产群体颖花数/叶面积分别提高9.7%和21.5%,实粒数/叶面积分别提高10.9%和17.8%,粒重/叶面积分别提高4.3%和8.4%;(4)超高产和高产群体穗型较大,每穗250粒以上的大穗比例较多,100粒以下的小穗比例较少;(5)顶四叶叶长顺序在不同产量水平群体间也有较大差异,中产群体以顶一叶最长、顶四叶最短,高产和超高产群体以顶二叶或顶三叶最长、顶四叶最短。因此,要实现贵州高原水稻超高产,需增加有效穗数、促大穗形成,确保抽穗期拥有适宜叶面积和较高的抽穗后干物质积累量。

Rice is one of the most important staple food crops in Guizhou province, it is critical to ensure food safety through continually improving grain yield per unit area. In order to study the population quality characteristics of indica hybrid rice with different yield levels in Guizhou plateau mountain area, field experiments were conducted at six planting regions in 2011 and 2012. The populations with super-high-yielding （12.0-14.5 t ha-1）, high-yielding （10.5-12.0 t ha-1）, and medium-yielding levels （9.0-10.5 t ha-1） were obtained from super hybrid rice Jinyou 785. To study their yield, yield components, and population quality characteristics. Productive panicle number was the most important factor influencing the rice yield across planting regions and years, followed by spikelets per panicle and filled grain percentage. The correlation between yield and grain weight was not sig- nificant. Between productive panicle number and yield, the direct path coefficient was 0.5822 in 2011 and 0.7304 in 2012, the correlation coefficient was 0.7771 in 2011 and 0.8858 in 2012. There was little difference in dry matter accumulation at heading among different populations, however, a significant difference in dry matter accumulation at maturity. Compared with high-yielding rice and medium-yielding flee, the averaged dry matter accumulations of super-high-yielding rice were 7.7% and15.9% higher, respectively. When values were averaged across years, compared with high-yielding rice and medium-yielding rice, the super-high-yielding rice had 9.7% and 21.5% higher ratio of spikelets per leaf area, 10.9% and 17.8% higher ratio of filled grains per leaf area, 4.3% and 8.4% higher grain weight per leaf area, respectively. As for the panicle size, compared with me- dium-yielding rice, both super-high-yielding and high-yielding rice had more percentage of large panicles with spikelets above 250 and less percentage of panicles with spikelets below 100. As to top four leaves, the medium-yielding rice had the longest 1 st leaf and lowest 4th leaf from top, meanwhile, the super-high-yielding and high-yielding rice had the longest 2nd leaf and lowest 4th leaf from top. Therefore, increasing productive panicle number and promoting large panicle formation will be helpful to im- prove rice yield, in addition, it is also very important to ensure optimum leaf area index at heading and increase the dry matter accumulations after heading stage.