作 者 ：冯洋 陈海飞 胡孝明 周 卫 徐芳森 蔡红梅
期 刊 ：植物营养与肥料学报 2014年 20卷 5期 页码：1051-1062
Keywords:rice, yield, nitrogen efficiency, cultivar screening,
摘 要 ：【目的】评价我国南方地区主推水稻品种氮效率，筛选氮高效和氮低效品种，并探索其高效和低效的原因及其生理机制。【方法】选用34份我国南方主推水稻品种，采用大田小区试验和盆栽试验，进行正常氮和低氮处理，利用产量法并结合产量构成因子、叶片SPAD值以及水稻地上部氮素累积量，筛选出氮高效和氮低效品种。【结果】 1）在2011年大田试验中，34个品种正常氮处理产量大多高于低氮处理的产量。通过对氮效率的分析发现，徽两优6号、广两优35和天优华占3个品种具有较高的氮效率，分别达到1.11、1.02和1.00，而秀水134、富稻2号和五丰优7025的氮效率较低，分别为0.55、0.61和 0.61。通过对各品种的产量构成因子分析发现，正常氮处理下，各品种产量构成因子大多高于低氮处理。在低氮条件下，氮高效品种的穗数和穗粒数以及千粒重均较高。通过筛选发现徽两优6号、广两优35和天优华占3个水稻品种表现为氮高效；秀水134、富稻2号和五丰优7025 3个品种表现为氮低效。2）通过2012年大田和盆栽试验的复筛，发现大田与盆栽试验结果基本一致。实际产量和理论产量均表现出徽两优6号和广两优35的产量和氮效率较高，秀水134、五丰优7025和富稻2号的氮效率较低。通过对各品种的产量构成因子分析发现，2012年大田试验中，在正常氮条件下，高效品种广两优35的穗数、千粒重均显著高于低效品种。在对SPAD值的分析中发现，2012年大田试验中，低氮处理下氮高效品种在同一生育时期其SPAD值普遍高于或者显著高于低效品种。2012年盆栽试验中，正常氮处理下，高效品种叶片SPAD值略高于低效品种。在对水稻地上部氮累积量的研究中发现，在正常氮处理下，不同生育期高效品种与低效品种间普遍没有显著性差异，仅低效品种秀水134显著低于其他几个品种；而在低氮处理下，在分蘖期高效品种与低效品种并无显著性差异，甚至高效品种徽两优6号氮素累积量还要低于低效品种；但在灌浆期和成熟期，两个高效品种的氮素累积量高于或显著高于低效品种。【结论】确定广两优35为高效品种，秀水134为低效品种。氮高效品种在低氮胁迫下，能够获得较高的穗数和穗粒数，从而获得较高产量。特别在生育后期，高效品种地上部能够积累更多的氮素，从而可促进光合作用，提高碳、氮同化效率，并获得较高产量。
Abstract:【Objectives】The objective of this study is to screen and evaluate the nitrogen efficiency of rice cultivars widely grown in South China, and investigate the different phsiology mechanisms between the high and low nitrogen efficient cultivars.【Methods】Thirty four rice cultivars were tested in field trials and pot experiments under both normal and low nitrogen supplies. The high and low nitrogen efficient cultivars were identified by analyzing parameters related to yield and its components, the leaf SPAD value and the aboveground nitrogen accumulation rate of rice. 【Results】 1)Field trials results in 2011 showed that the yields under normal nitrogen treatment were higher than those under low nitrogen treatment for most of the 34 cultivars. Huiliangyou 6, Guangliangyou 35 and Tianyouhuazhan had higher nitrogen efficiencies with 1.11, 1.02 and 1.00, respectively; Xiushui 134, Fudao 2 and Wufengyou 7025 had lower nitrogen efficiencies with 0.55, 0.61 and 0.61, respectively. Similarly, the yield components under the normal nitrogen treatment were higher than those under the low nitrogen treatment for most of the 34 cultivars. The cultivars with higher nitrogen efficiencies have higher panicle number, spikelet number per panicle, as well as thousand grain weight under low nitrogen condition. As a consequence, Huiliangyou 6, Guangliangyou 35 and Tianyouhuazhan were screened as the high nitrogen efficient rice cultivars, and Xiushui 134, Fudao 2 and Wufengyou 7025 as the low nitrogen efficient ones. 2) Field and pot experiments in 2012 showed similar results. Both the actual and theoretical yields and nitrogen efficiencies of Huiliangyou 6 and Guangliangyou 35 are in the high ranking of the tested 34 cultivars, while Xiushui 134, Wufengyou 7025 and Fudao 2 in low ranking. In field trial, both the panicle number and thousand grain weight of high nitrogen efficient cultivar, Guangliangyou 35, were significantly higher than those of low nitrogen efficient ones under normal nitrogen treatment. Under low nitrogen condition, the high N efficient cultivars performed higher or significantly higher SPAD values than the low nitrogen efficient ones. Under normal nitrogen supply in the pot experiment, the SPAD values of the high nitrogen efficient cultivars were slightly higher than the low ones.Under the normal nitrogen condition, there were no significant differences in aboveground N accumulation between the high and low N efficient cultivars at each growth stage, except for Xiushui 134. Under the low N condition, no significant differences at tillering stage, except high N efficient cultivar Huiliangyou 6, in which the N accumulation even lower than N low efficient cultivars. At the heading stage and mature stage, the N accumulation in two high N efficient cultivars were significantly higher than those in low ones. 【Conclusion】Guangliangyou 35 is identified as the highest nitrogen efficient cultivar and Xiushui 134 as the lowest nitrogen efficient cultivar. The high nitrogen efficient cultivar has higher panicle number and spikelet number per panicle under low nitrogen supply condition, which led to the higher yields than the low nitrogen efficient cultivar. Compared with that in the low nitrogen efficient cultivars, the more nitrogen was accumulated in the high nitrogen efficient cultivars at the late growth stage, which enhanced photosynthesis, the carbon and nitrogen assimilation, and then improved yields.
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