两系杂交稻两优培九产量构成及其生态关联

为探明两系杂交稻两优培九在不同生态条件下的产量水平及其构成,揭示引发产量变异的主要构成因素及其与生态因子的关联性,应用2006和2007年中国南方稻区8个气候生态试验点的生育进程、茎蘖消长、籽粒灌浆、产量及其构成与同期气象数据,建立了产量与其构成因素、各构成因素与温光因子的统计关系。两优培九稻谷产量变幅为5~18 t/hm2。以每平方米总粒数引发产量变异的贡献率最高(60.5%),其次为结实率(32.9%)。扩增总粒数主要依赖每平方米穗数与每穗粒数的平衡增加。华南双季早稻生育中期的梅雨寡照对于每穗粒数、开花期持续高温对于结实率、长江中下游麦(油)茬稻生育前期高温对于穗数、乳熟期日照骤减对于结实率都有负面影响。云南河谷地区稻作期的适温、长日、强辐射,促成每平方米425穗、7.2万粒、结实率90%的产量结构,产量高达18.2 t/hm2。结实率累积动态呈左偏不对称的S形曲线。谷粒干物质积累呈Logistic曲线,拐点在花后8~14 d。穗数与本田营养生长期、每穗粒数与生育中期日照时数、结实率与后期日照时数都呈极显著正相关。开花期持续高温、乳熟期障碍型冷害和台风等气象灾害制约结实率的提高。每平方米总粒数是影响两优培九产量的主要因素,发挥其大穗优势、在有效分蘖临界期形成目标穗数的茎蘖数、构建足穗大穗群体,是进一步提高其产量的主攻方向。

Grain Yield Components and Their Relation to Ecological Conditions of Two-line Hybrid Rice Liangyou Peijiu

To understand the grain yield level and its components of the two-line hybrid rice Liangyou Peijiu growing in different ecological conditions and find out the major components resulting in yield variation and their relationship to ecological factors,the statistical relations were established between yield and yield components and between yield components and light and temperature factors based on the growing process,tillering,grain filling,yield and yield components of Liangyou Peijiu planted in eight ecological locations in the southern rice growing areas of China in 2006 and 2007 and the corresponding meteorological data during the same period.The grain yields of Liangyou Peijiu ranged from 5~18 t/hm2.The yield contribution from the spikelets per m2 was greatest(60.5%) and then from the seed setting rate(32.9%).The increase of spikelets per m2 was mainly from a balanced increase of panicles per m2 and spikelets per panicle.For the early season rice in Southern China,the rainy and less light conditions in the middle growing stages had a negative effect on spikelets per panicle and the high temperature in flowering stage on seed setting rate;for the single season rice after wheat in lower and middle reaches plain of Yangtze River Valley,the high temperature in the early growing stage had a negative effect on the panicles per m2,the sharp decrease of sunshine hours in the grain filling stage on seed setting rate.The favorable conditions of suitable temperature,long day length and high light intensity resulted in a yield as high as 18.2 t/hm2 with 425 panicles/m2,72 000 spikelets/m2 and 90% of seed setting rate for the single season rice in Yangtze River Valley of Yunnan.The dynamic seed setting rate showed an unsymmetrical S-shape curve,and the dry matter accumulation of grains showed a logistic curve with its inflexion points at 8~14 days after flowering.There existed a very significant positive correlation between the panicles per m2 and the vegetative duration in main field,between spikelets per panicle and sunshine hours in the middle growing stage,and between the seed setting rate and the sunshine hours in late growing stage.The unfavorable climatic factors or calamities such as high temperature in flowering stage,cool temperature in the milking stage and typhoon were the limitations to increase of the seed setting rate.The number of spikelets per m2 was the most important factor for the yield of Liangyou Peijiu,so the principal direction to further increase its yield was to take advantage of the superiority of large panicles and produce enough tillers as much as the projected effective panicles within the effective tillering stage so as to achieve a high-yielding population with large and enough panicles.