华南双季直播稻品种筛选及其产量形成特征研究

Selection and Yield Formation Characteristics of Double-cropping and Direct Seeding Rice in South China

为筛选适宜在华南双季稻区种植的高产直播稻品种,明确其产量形成特征,以14个水稻品种为材料,在早、晚两季直播条件下开展田间试验,测定各品种的产量及其构成因子、物质生产分配和氮素利用效率。结果表明,不同水稻品种的产量存在显著差异,早、晚季产量分别在3.30~6.12t/hm2之间和4.04~6.05t/hm2之间。15WHZ、培杂泰丰和粤杂889宜作早季直播品种,聚两优751、天优122和天优华占宜作晚季直播品种,五优308则可早晚两季兼用;直播稻产量与结实率、总生物量、收获指数、总吸氮量、氮素籽粒生产效率和氮素收获指数呈显著正相关,而与有效穗数及不同阶段物质积累量均无显著相关,早、晚两季趋势一致。早季直播稻高产应以促进籽粒灌浆充实为主要途径,而晚季则应以扩库和促进结实二者兼顾。总生物量大、收获指数和氮素利用效率高是直播高产品种的重要特征。研究结果可为华南双季直播稻品种选择和高产栽培提供参考。

In order to screen the rice varieties suitable for direct seeding in South China double-cropping rice region and determine their yield formation characteristics, a field experiment was carried out using 14 rice varieties as materiels. The results showed that, under the direct seeding condition, the yield of different rice varieties was significantly different, and the early and late season yields were 3.30~6.12 t/hm2 and 4.04~6.05 t/hm2, respectively. 15WHZ, Peizataifeng and Yueza 889 were suitable for early season direct seeding;Juliangyou 751, Tianyou 122 and Tianyouhuazhang were suitable for late season direct seeding;Wuyou 308 could be used both in early season and late season. The grain yield of direct-seeding rice has significant positive correlation with seed setting rate, total biomass, harvest index, total N uptake, N use efficiency of grains and N harvest index, and has no significant correlation with effective panicles and biomass accumulation at specific growth stages. In early season, the main way to increase yield is to promote grain filling;in the late season, should enlarge sink size and promote grain filling both at the same time. In general, high-yield varieties were superior in total biomass, harvest index and nitrogen use efficiency.