【作者】 沈建辉；

【导师】 曹卫星；

【作者基本信息】 南京农业大学 ， 作物栽培学与耕作学， 2003， 博士

【摘要】 协调改善专用小麦产量和品质的关系是小麦生产需要解决的关键问题。研究小麦籽粒品质形成的机理和调控原理对于深化小麦品质生理研究及指导专用小麦的调优栽培具有重要的理论意义和广阔的应用前景。本文以不同类型专用小麦品种为材料，综合研究了不同氮肥运筹及NPK配比对专用小麦产量、品质形成及C／N物质运转的影响，阐明了旗叶内源激素在小麦植株C／N运转及籽粒品质形成的作用，进一步明确了不同生态环境下籽粒蛋白质形成的调控机制及调优栽培的氮肥运筹模式。结果如下： 在大田高产条件下，研究了不同追氮时期对不同生态环境下(徐州和南京)不同类型专用小麦品种开花前后氮素同化运转、籽粒产量和蛋白质含量的影响。结果表明，拔节和孕穗期追氮均提高了小麦产量和籽粒蛋白质含量与产量，但过迟追氮不利于产量和蛋白质含量的同步提高。不同追氮处理显著提高了徐麦26和苏麦6号花后氮素积累量，降低了营养器官贮存氮素向籽粒的转运率，但提高了淮麦18营养器官贮存氮素向籽粒的转运量和转运率，而对宁麦9号氮素转运的影响较小。分析表明，徐麦26和苏麦6号籽粒蛋白质合成所需氮素主要来源于花后氮素同化，而淮麦18则更多地依赖于开花前贮存氮素的再动员与分配，宁麦9号对花后氮素积累与运转的依赖均较小。 在徐州、姜堰和金坛三个生态点进行田间试验，研究了不同施氮水平和追肥时期对两个不同专用小麦类型籽粒产量和品质的影响。结果表明，与低氮处理相比，增加施氮量提高了小麦产量，在225kg／hm2氮水平下，随氮肥后移产量降低；增加施氮量显著提高了籽粒蛋白质和湿面筋含量、谷蛋白含量和谷／醇比；沉降值随不同地点而表现不同的特征，在长江下游麦区增加施氮量提高了面粉沉降值。增加施氮量促进了花后干物质向籽粒的运转，提高开花期氮素的积累及花后氮素转运。分析表明，籽粒蛋白质含量的提高与花后氮素运转及同化相关，较高的产量与较高花后干物质运转量、开花期叶绿素含量及灌浆期净光合速率有关。认为对于弱筋小麦需适当降低氮肥用量配合拔节期追肥，而对于强筋小麦适当提高氮肥用量配合孕穗期追肥可以实现小麦优质高产的协调栽培。 采用蛋白质含量不同的两个小麦品种，研究了不同施氮水平(112.5 kgN／hm2和氮肥运筹对专用小麦氮素营养和籽粒品质形成的影响225k酬/hm2)及基追比(“/34和34/“)对小麦c加积累与转运规律、产量及籽粒品质形成的影响。结果表明，高氮水平下基追比34/66、低氮水平下基追比66/34提高了小麦产量。高氮水平和追肥比例提高了小麦籽粒蛋白质、面筋含量、沉降值和谷/醇溶蛋白比例，降低了贮存氮素和干物质的转运率，但提高了花后氮素的转运量。籽粒蛋白质含量与开花期氮积累量和花后氮转运量显著相关而与氮转运率、花后氮同化及干物质积累和运转无关;淀粉含量与花后氮素转运量及转运率极显著负相关。与低氮处理相比，高氮处理下开花期旗叶IAA、GA、ZR含量降低，而ABA含量和AB户以ZR比例升高。相关分析表明，花后氮运转率与开花期旗叶IAA和ZR含量及灌浆期ABA/ZR显著正相关，与开花期AB刀IAA比例显著负相关。氮素转运量与灌浆期旗叶ABA含量显著正相关。上述结果表明，不同氮处理下小麦开花后旗叶激素含量及平衡的差异是调节花后N/C物质运转的重要生理基础，而开花期旗叶IAA、ZR含量和灌浆期ABA含量和AB刀ZR平衡在籽粒蛋白质和淀粉合成中起着重要的作用。 大田条件下研究了氮磷钾肥施用量对优质中筋小麦扬麦10号和优质弱筋小麦宁麦9号籽粒产量与品质性状、旗叶光合特性及植株氮素积累与分配的影响。结果表明，扬麦10号以中(225 kg爪m2)、高氮(337.5 kg/hmZ)高磷(150 kg爪mZ)高钾(一sok幼而2)和中氮高磷低钾(30 kg爪m2)处理籽粒产量最高，其籽粒蛋白质含量亦较高.宁麦9号亦以上述3处理产量最高，以中、高氮高磷高钾两个处理籽粒蛋白质含量较低;宁麦9号籽粒蛋白质含量以低氮(l12，5 kg瓜m2)高磷高钾和中氮低磷(30k幼助2)高钾处理最低，其产量也最低。两品种籽粒产量与开花期旗叶光合参数、叶面积指数 (LAI)显著相关;宁麦9号开花期叶片全氮含量及开花至成熟期叶片全氮含量差与籽粒蛋白质呈二次曲线关系。更多还原

【Abstract】 Synchronously improving grain yield and quality is a key target in the production of specialty wheat. Elucidating the mechanism and regulation principles for grain quality formation in wheat is of important significance for developing quality formation physiology and guiding specialty wheat production in practice. The present study characterized C/N assimilation transfer, endogenous hormone change in flag leaves and photosynthesis after anthesis in relation to the formation of grain yield and quality in different wheat genotypes under different nitrogen regimes, and established a regulation mechanism on quality formation of different specialty wheat and nitrogen management system under different ecological regions. The results were showed as below.Field experiments were carried out under high yield conditions at Xuzhou and Nanjing to investigate the effects of nitrogen dressing time on nitrogen accumulation and transfer, grain yield and protein content in two types of specialty wheat, middle- and weak gluten wheat. The results showed that nitrogen dressing at jointing and booting increased grain yield and protein content and yield, but too late dressing at heading and flowering might be unfavorable for simultaneous increases in grain yield and protein content. Compared with control, dressing treatments significantly increased post-anthesis nitrogen assimilation in Xumai 26 of Xuzhou and Sumai 6 of Nanjing, reduced the transfer ratio of reserved nitrogen in vegetative organs to the grains, but increased that in Huaimai 18. Grain protein content of Xumai 26 and Sumai 6 was significantly correlated with post-anthesis nitrogen assimilation. However, grain protein content in Huaimai 18 was significantly correlated with the transfer amount of reserved nitrogen in vegetative organs. These results indicate that different cultural strategies should be adopted for regulating grain protein content in different specialty wheat cultivars.At different eco-sites of Xuzhou, Jiangyan and Jintan, effects of different nitrogen rates and dressing times on grain yield and quality characters of two different specialty wheat genotypes were investigated under the same management practices. The results showed that grain yields increased under medium (225kg/hm2) and high nitrogen rates (300kg/hm2) compared with low nitrogen rate (150kg/hm2). Grain yield decreased withdelayed dressing time at 225kg/hm . The content of protein, wet gluten and gluteinin and ratio of glutenin/gliadin in grains significantly increased at medium and high nitrogen rates compared low nitrogen rate. Post-anthesis DW transfer, N accumulation and transfer amount were also enhanced. The results indicate that increased protein content at medium and high N rate and late dressing time was associated with higher N transfer and assimilation after anthesis, increased grain yield was associated with more DW transfer amount, higher chlorophyll content at anthesis and net photosynthetic rate during grain filling. To synchronously improve grain yield and quality, different N regimes should be adopted for different specialty wheat. Reducing N rate with dressing at jointing will favor grain yield and quality formation for weak-gluten wheat genotypes, and increasing N rate with later dressing at booting and heading will be more desirable for medium- or strong-gluten wheat cultivars.Field experiments were conducted to investigate the effects of nitrogen rate and dressing ratio on grain quality formation and characteristics of post-anthesis carbon and nitrogen assimilation and transfer. Two wheat cultivars with different grain protein contents were used, i.e. Xuzhou 26 (high protein) and Huaimai 18 (low protein). The results showed that wheat yield was higher at nitrogen ratio of 34/66 under high nitrogen level and at 66/34 under low nitrogen level. High nitrogen rate and dressing ratio increased the contents of protein and gluten, sedimentation value and glutenin/gliadin ratio, reduced the ratio of N and DW transfer after anthesis, but increased N transfer a更多还原