播期对不同品种类型机插稻生长特性的影响

摘要

为了探讨河南省稻-麦两熟区播期对不同品种类型机插稻生长特性的影响，在豫南稻区罗山，以生产上主推的常规中熟中粳、常规和杂交迟熟中粳、常规早熟晚粳和迟熟中籼5个类型品种为材料，通过分期播种试验，对不同品种类型毯苗机插水稻的产量及其构成因素、茎蘖数、干物质量及群体生长率等方面进行了系统的比较研究。结果表明：1）在试验设置的播期范围内，不同品种机插稻平均产量在播期间和品种类型间差异达极显著（P<0.01），即随着播期的推迟呈极显著下降（P<0.01），第Ⅰ播期（5月11日，10.60 t/hm2）较第Ⅱ（5月16日）－Ⅵ（6月5日）播期分别增产2.15%～28.81%；杂交迟熟中粳产量（10.44 t/hm2）极显著高于其他4种品种类型（P<0.01），较其他类型品种分别增产9.20%～17.53%。同一品种类型，除了中熟中粳的产量在第Ⅱ播期（5月16日）最高，随后呈显著递减趋势外，其他4种类型品种机插稻的产量均是随着播期的推迟呈极显著下降趋势（P<0.01），但品种类型间下降幅度不同。2）在产量构成因素中，除结实率在年份间差异不显著、在播期间和品种类型间差异极显著外，其他产量构成因素在年份间、播期间和品种类型间差异均达极显著（P<0.01）。同一类型品种，除中熟中粳的结实率随播期推迟呈先略升后明显下降趋势外，其他类型品种的穗数、每穗颖花数、总颖花量、结实率和千粒质量等产量构成因素均是随播期的推迟呈显著（P<0.05）或极显著（P<0.01）下降趋势；在播期影响下，每穗颖花数和结实率的变化较大，穗数和千粒质量的变化较小；且对产量影响大小为每穗颖花数＞结实率＞穗数＞千粒质量；相关分析表明，产量与每穗粒数、总颖花量和结实率呈显著或极显著正相关，与穗数和千粒质量呈负相关；总颖花量与每穗粒数呈极显著正相关，与穗数呈负相关。进一步通径分析表明，对产量的贡献率最大的是群体颖花量，最小的是千粒质量，对群体颖花量的贡献率较大的是每穗颖花数，较小的是穗数。3）随着播期的推迟，不同品种类型水稻的茎蘖数在拔节期呈明显的递增趋势，在抽穗期和成熟期呈明显的下降趋势；单茎和群体干物质量、群体生长率在主要生育时期均呈逐渐下降趋势；成穗率和收获指数均呈逐渐下降趋势；但品种类型间和播期间下降幅度不同。综合机插稻高产及生育安全性考虑，豫南稻区首选杂交迟熟中粳“穗大粒多”型品种，适宜播期可推迟到5月25日。该研究结果为河南省豫南稻区机插水稻高产高效生产及配套品种的科学选用提供参考。%The objective of the study was to explore the effects of seeding date and variety on the growth characteristics of mechanical transplanted rice in the rice-wheat cropping system in the rice area of southern Henan. Taking 5 rice varieties i.e. conventional medium-maturing medium japonica rice variety, conventional and hybrid late-maturing medium japonica rice varieties, conventional early-maturing late japonica rice variety and hybrid late-maturing medium indica rice variety as experimental materials, sowing experiments were carried out. The effects of different seeding dates on grain yield and yield components, number of stems and tillers, dry matter weight and population growth rate of mechanical planted rice were comparatively analyzed. The results showed that: 1) Within the set range of seeding date in the experiment, average yield of mechanical planted rice showed very significant difference among different sowing dates and varieties (P<0.01), but no significant difference between different years. This was particularly evident for the yield of hybrid late-maturing medium japonica rice variety (10.44 t/hm2) that was 9.20%-17.53% higher than the other 4 varieties (P<0.01). The output of conventional medium-maturing medium japonica rice variety was the highest in the second sowing period (on May 16) and subsequently showed a gradual decrease. The yields of other rice varieties were all the highest in the first seeding period (on May 11), and showed a trend of gradual decline with the delayed seeding date (P<0.01), but the decrease amplitudes were different among different rice varieties and sites. 2) In different yield components of mechanical planted rice, the difference of seed setting rate was not significant between the years but very significant for different sowing dates and varieties, while the differences of other yield components were all very significant for different years, sowing dates and varieties (P<0.01). The seed setting rate of conventional medium-maturing medium japonica rice variety slowly increased at first and thendecreased significantly since the second sowing data, but the yield components of other rice varieties such as panicle number, number of spikelets per panicle, total spikelets, seed setting rate, 1000-grain weight all showed a significant (P<0.05) or extremely significant (P<0.01) declining trend. Different seeding dates had a significant influence on number of spikelets per panicle and seed setting rate, but less significant influence on 1000-grain weight and panicle number. Correlation analysis showed that the effects of yield components on the yield from high to low were as follows: number of spikelets per panicle > seed setting rate > panicle number > 1000-grain weight, and grain yield showed significant or extremely significant positive correlation with number of spikelets per panicle, total spikelets and seed setting rate, but showed negative correlation with panicle number and 1000-grain weight. Total spikelets showed an extremely significant positive correlation with number of spikelets per panicle, but showed a negative correlation with panicle number. Further path analysis showed that the rate of contribution to rice yield was total spikelets > seed setting rate > 1000-grain weight, and the rate of contribution to total spikelets was number of spikelets per panicle > panicle number. 3) With the delaying of seeding date, the number of stems and tillers showed an obvious increase at jointing stage and decreased at heading and maturity stage. Dry matter weight per stem and population, and population growth rate showed a gradual decline at jointing, heading and maturity stage depending on different rice varieties and seeding dates, but spike rate and harvest index had significant difference between rice varieties and seeding dates. Overall considering high yield and growth safety for mechanical transplanted rice, the preferred choice should be hybrid late-maturing medium indica rice variety for southern Henan, and the suitable seeding date may be delayed to May 25. The results will provide a reference for the high-yield and efficient production of different rice varieties under mechanical planting and for the choice of best possible varieties in southern Henan Province.