【作者】 李淑文；

【导师】 肖凯； 李雁鸣；

【作者基本信息】 河北农业大学 ， 作物栽培学与耕作学， 2004， 硕士

【摘要】 试验于2001～2003年度在河北农业大学教学实验基地进行。两年度中取得的主要研究结果如下： 1．200l～2002年度，对28个不同小麦品种(基因型)在未施氮条件下的籽粒产量研究发现，不同小麦品种的籽粒产量具有明显差异。聚类分析结果表明，供试品种(基因型)可划分为氮高效、氮中效和氮低效三类，分别包括2、7和19个品种(基因型)。表明生产中应用的品种(基因型)中，耐低氮能力强的氮高效品种极少。在低氮下筛选的不同氮效率品种(基因型)，对氮素响应能力上没有明显不同。 2．在未施氮胁迫条件下，各种氮效率品种的成熟期植株全氮含量表现为氮高效＜中效＜低效；单位土地面积的植株干重和氮累积量则相反。表明氮高效品种在氮胁迫下单位土地面积具有较强的植株氮素积累和干物质生产能力。施氮使不同氮效率品种的籽粒产量、成熟期植株全氮含量、单位面积植株干重和氮累积量均明显增加。 3．小麦氮效率(NUE)可分解为吸收效率(UPE)和利用效率(UTE)。在氮高效、中效和低效品种中，在UPE和UTE上均存在着高、中和低几种类型。施氮使各氮效率类型的NUE和UTE下降，而UPE在两种氮素水平下相近。表明在低氮胁迫条件下氮高效类型品种NUE的提高主要起因于UTE的增加。不同氮效率类型间的氮响应度均值的差异较小，且在同一类型间具有较大的变异系数。 4．在未施氮条件下，氮高效品种的成熟期株高较中效和低效类型品种明显增加，成熟期株高可作为筛选耐低氮能力强的小麦品种的指标之一。不同氮效率品种成熟期的穗长、总小穗数和结实小穗数差异较小，成熟期单株粒重和单株干物重的表现与各自籽粒产量和氮效率的表现一致。与未施氮胁迫下相比，施氮使不同氮效率品种成熟期植株株高、穗长、总小穗数和结实小穗数均有不同程度的增加。 5．不同氮效率品种的产量构成因素在未施氮胁迫条件下表现为下述特征：在单位面积穗数上，氮高效＞中效＞低效；在穗粒数上的表现与单位面积穗数相反；在干粒重上，以氮中效＞高效＞低效。单位面积穗数的多少对低氮胁迫下的氮效率和籽粒产量的高低具有重要影响。施氮使不同氮效率类型品种的单位面积穗数和穗粒数增加，千粒重降低。三个构成因素对施氮的反应在不同氮效率类型间没有差异。 6．在不同氮水平下，不同氮效率品种间拔节期、抽穗期和成熟期的植株全氮含量均无明显差异。供试品种在施氮条件下各生育时期植株氮累积量的增加与植株干物质积累量的增大密切相关。拔节至成熟阶段植株氮累积量表现为氮高效＞中效＞低效。阶段氮累积量以氮高效品种对供氮反应较为迟钝、中效次之，低效较为敏感。 7.在未施氮胁迫条件下，不同氮效率品种各生育时期的株高、叶面积系数 (LA工)、群体干物重(PDw)和群体生长参数，包括:作物生长率(CGR)、净同化率(NAR)及光合势(Pp)均以氮高效>中效>低效;施氮条件下，各氮效率品种的NAR降低，除NAR外的上述其它群个体性状和生长参数增加。 8.倒三叶和旗叶的光合速率(P。)、气孔导度(95)、叶绿素含量(Chl)以及叶绿素含量缓降期(RSP)、光合速率高值持续期(PAD)、平均Pn、叶面积(LA)和叶源量(LSC)在不同氮效率品种中，在未施氮胁迫下均表现为氮高效>中效>低效，施氮条件下上述参数的数值增大;胞间C02浓度(C。)在不同氮效率品种中的表现以及对施氮的反应则相反。在不同氮素水平下，供试品种倒三叶和旗叶叶源量LSC与光合生理参数PAD、RSP、LA及P。(平均)均呈极显著或显著正相关。 9.研究表明，在低氮胁迫条件下，籽粒产量或NUE与倒三叶、旗叶的叶绿素含量缓降期(RSP)、平均P。和光合速率高值持续期(PAD)呈显著和极显著正相关，表明可用RSP和PAD的长短以及叶片平均P。作为评价低氮胁迫下籽粒产量和氮效率的重要指标。 10.在不同氮素水平下，不同氮效率品种倒三叶和旗叶生长期间各测试点可溶蛋白含量(Sp)的动态变化呈单峰曲线，硝酸还原酶活性(NRA)的动态变化呈双峰曲线。在未施氮条件下，不同氮效率品种在上述叶位各测试点SP和NRA上的差异不明显，施氮使供试品种倒三叶和旗叶各测试点的Sp和NRA均有所增加。研究表明，叶片Sp和NRA作为预测小麦籽粒产量和氮效率高低指标的可行性仍有待今后进一步探讨。更多还原

【Abstract】 The experiment was carried out at the experimental station of Hebei Agricultural University in 2001-2003. The results are summed as follows:1. In 2001-2002, 28 wheat varieties (genotypes) were selected to study the yield performance under nitrogen stress condition. It is found that there were obvious differences in grain yield among them. The cluster analysis indicated that the tested varieties could be classified into three categories with different nitrogen use efficiencies (NUE), including high efficiency, middle efficiency and low efficiency, corresponding 2, 7 and 19 varieties in each category. It showed that few varieties with high NUE could be found in the present wheat production. There had not big differences on the capability to nitrogen response in the tested 28 varieties.2. Under the condition without nitrogen application, the total nitrogen concentration in plants at maturity stage showed the highest in varieties of high NUE, then of middle NUE, the lowest of low NUE, and the adverse results were found on plant dry matter weight per area and nitrogen accumulation amount in the different NUE varieties. Then this showed that the high NUE varieties had stronger capabilities of N accumulation and dry matter production in plants under N stress condition. N application obviously increased the grain yields, total N concentration of plants at maturity stage, plant dry matter weights and N accumulation amounts of plants in all tested varieties.3. Wheat N use efficiency can be divided into uptake efficiency (UPE) and utilization efficiency (UTE). There existed types high efficiency, middle efficiency and low efficiency in UPE and UTE in the tested varieties. N application decreased NUE and UTE in all varieties. Similar UPE was found for each variety under different N conditions, indicating the increase of NUE in high NUE varieties under N stress condition came from the increase of UTE. The average value of N response degree changed little in different NUE varieties. Big variation coefficients in statistics were existed in varieties of same NUE category.4. Under N stress condition, the plant height at maturity in high NUE varieties was much higher than those in middle NUE and low NUE varieties. It can be used as one important index to screening wheat variety with higher ability to resist N stress. The spike length, total spikelet number and fruitful spikelet number had no obvious difference in tested varieties. The grain weight and dry matter weight per plant at maturity in varieties with different NUE had the same tendency as those in grain yield and NUE. Compared to N stress, N application increased the plant height at maturity, spike length, total spikelet number and fruitful spikelet number, grain weight dry matter weight per plant at different extent in the tested varieties.5. A follow characteristics on yield components in tested varieties under N stress condition was found as follows: The spike number per area showed the highest in high NUE, then middle NUE, the lowest in low NUE; The adverse effect to the spike number per area was found in kernel number per spike; The per 1000 grain weight was the highest in middle NUE, then high NUE, the lowest in low NUE. The spike number per area had important effect on the NUE and the grain yield under N stress condition. N application increased the spike number per area and kernel number per spike and decreased the per 1000 grain weight in tested varieties. No differences were found on responding to N in three yield components in tested varieties.6. At different levels of N, there were not significant differences on total N concentration at jointing stage, booting stage and maturity stage in tested varieties. There existed a close correlation between the increase of N accumulation amount and enhancement of dry matter weight in plants at each growth stage. The N accumulation amounts in plant during jointing to maturity are the most in high NUE, then in middle NUE, the last in low NUE. The response to N application in the N accumulation amounts in high,更多还原