作 者 ：徐富贤,张林,熊洪,朱永川,刘茂,郭晓艺
期 刊 ：植物营养与肥料学报 2014年 20卷 6期 页码：1329-1337
Keywords:water-logged paddy field, hybrid rice, genotype, shifting part of nitrogen fertilization from the basal-tillering to panicle initiation,
摘 要 ：【目的】水稻采用前氮后移的施肥方式有利于提高氮肥利用效率并获得高产,但不同杂交组合是否适应尚无研究报道。为此,本文以20个杂交中稻组合为材料,研究了施氮方式与杂交组合间的产量及库源结构的互作效应。【方法】在冬水田高产栽培条件下,试验设“前氮后移(底肥:促花肥:保花肥=6:2:2)”与“重底早追(底:蘖=7:3)”两种施氮方式,采用裂区设计,以施氮方式为主处理,杂交组合为副处理进行田间试验。对两种施氮方式的产量差值与各施氮方式下产量性状间进行了相关、 回归与通径分析。【结果】20个杂交组合分别在两种施氮方式下的产量相关性状均达极显著,方差分析F值8.89~149.08(P＜0.01)。两种施氮方式下,20个杂交组合的产量性状及粒叶比的成对数据平均值的差异显著性分析表明,前氮后移处理的有效穗数比重底早追显著降低,但其结实率和千粒重分别显著或极显著提高,最高苗数、 穗粒数和粒叶比在两种施氮方式间差异不显著。不同杂交组合在两种施氮方式间的产量表现不尽相同。20个杂交组合前氮后移平均产量8981.90 kg/hm2,比重底早追增产1.62%;前氮后移处理中,内5优306、 蓉18优447、 内5优317和川谷优7329四个组合不仅产量较高,而且均分别比重底早追法极显著增产。前氮后移比重底早追的增产效果与两种施氮方式下杂交组合的穗粒数呈极显著负相关,相关系数分别为-0.7870和-0.7986(P＜0.01)。其原因在于,穗粒数较少的组合,其分蘖力较强,在前氮后移情况下,仍能确保较多的有效穗数,而且穗粒数和结实率因施用穗肥有一定提高,最终表现为“前氮后移”比“重底早追”法显著或极显著增产;而穗粒数过大的组合,其分蘖力较弱,在前氮后移前期施氮量较少情况下,因最高苗数明显不够,有效穗数显著下降,加之穗粒数有所降低而减产。【结论】前氮后移增产量(y)与杂交组合穗粒数(x)的关系可表述为 y =2607.9-11.02x (R2=0.6308)。大面积生产中,穗粒数≤237粒可作为采用前氮后移施肥法的杂交组合品种的选择指标。
Abstract:【Objectives】Shifting part of nitrogen fertilization from the basal-tillering to panicle initiation (PBSP) of rice is beneficial to improve nitrogen use efficiency and grain yield of paddy rice, however, limited information is available on the yield performance among different hybrid rice cultivars grown under water-logged paddy field. This study was conducted to determine cultivar difference in grain yield and in the response of source-sink structure to PBSP. 【Methods】 Twenty hybrid rice cultivars were grown under the same total nitrogen (N) fertilizer input with two different application strategies: part of nitrogen fertilizershifted from the basal-tillering stage to the panicle initiation (PBSP, the ratios of 60%, 20% and 20% of total N fertilizer were applied at basal, spikelet-promoting fertilizer, and spikelet-protecting fertilizer, respectively), and a heavy basal N plus top dressing at the early tillering stage (HBET, the ratios of 70% and 30% of total N fertilizer are applied at basal, and 7 day after transplanting, respectively). The treatments were arranged in a split-plot design with the application strategy as main plots and cultivars as subplots. The differences of grain yield and yield components between PBSP and HBET were analyzed by correlation, regression and path analysis based on the mean measurements of the triplicate. 【Results】There are significant differences of grain yield and yield components between PBSP and HBET with the F value ranging from 8.89**to 149.08**. Averagely, the grain filling percentages and thousand grain weights of the twenty hybrid rice cultivars treated with PBSP are significant higher than those with HBET, while the panicle numbers per m2 with PBSP are significant lower, and there are no significant differences in the maximum tiller numbers per m2, spikelet numbers per panicle and ratios of spikelets per m2 to leaf area. The differences of grain yield of hybrid rice cultivars between PBSP and HBET are fluctuated. The average grain yield of hybrid rice cultivars with PBSP is 8981.90 kg/ha, which is 1.62% higher than that with HBET. Four of the twenty hybrid rice cultivars (nei 5you306, Rong18you447, Nei5you317 and Chuanguyou7329) produce significant higher grain yields under PBSP. For a given hybrid, negative correlation is observed between grain yield differences of the PBSP vs the HBET and the spikelet numbers per panicle (r=-0.7870** for PBSP, and -0.7986** for HBET). The relatively higher grain yields with PBSP are mainly due to the higher panicle number per m2, spikelets per panicle and grain filling percentage. The hybrid rice cultivars with larger panicles produce lower grain yield under PBSP, and lower maximum tillers, panicle number per m2 and spikelets per panicle are responsible for lower grain yield of hybrid rice cultivars with larger panicles. 【Conclusions】The hybrid rice cultivars with spikelet number per panicle less than 237 can be suggested as a criterion suitable for the PBSP fertilization in all-time waterlogged paddy fields.
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