CAJ | 학술논문

为探讨乙矮合剂调控夏玉米氮素同化和防止后期早衰的生理机制,为建立华北夏玉米区密植高产稳产化学调控技术提供理论依据,2013—2014年在中国农业科学院新乡试验站,以中单909和浚单20为材料,设置乙矮合剂(ECK)和密度梯度处理,研究密度梯度对花后玉米穗位叶氮同化特征和早衰的影响,以及 ECK 的化学调控效应。结果表明,灌浆期(花后0~40 d),穗位叶硝酸还原酶(NR)活性和谷氨酰胺合成酶(GS)活性随密度增加而显著下降；灌浆后期(花后30~40 d),谷草转氨酶(GOT)和谷丙转氨酶(GPT)活性随种植密度增加而显著降低。穗位叶叶绿素相对含量、可溶性蛋白含量和游离氨基酸含量在灌浆中后期(花后20~40 d)随种植密度增加而显著降低；两品种产量在7.5万株 hm–2密度达最大值,7.5~10.5万株 hm–2密度群体产量下降,高密群体易发生早衰。ECK 处理显著提高了各密度群体灌浆中后期(花后20~40 d)穗位叶 NR 活性、GS 活性、游离氨基酸含量、可溶性蛋白含量和叶绿素含量；显著提高了高密群体(7.5~10.5万株 hm–2) GOT 活性和 GPT 活性；较高密群体下(7.5~10.5万株 hm–2),中单909和浚单20较各自对照的增产幅度分别为5.59%~6.63%和6.73%~8.10%。ECK 处理提高了高密群体夏玉米穗位叶片氮代谢关键酶活性及其产物含量,保证密植群体氮代谢正常进行,有效防止早衰及提高产量。综上所述,采用合理的种植密度并结合喷施乙矮合剂可作为华北夏玉米区高产栽培的重要技术措施。
위탐토을왜합제조공하옥미담소동화화방지후기조쇠적생리궤제,위건립화북하옥미구밀식고산은산화학조공기술제공이론의거,2013—2014년재중국농업과학원신향시험참,이중단909화준단20위재료,설치을왜합제(ECK)화밀도제도처리,연구밀도제도대화후옥미수위협담동화특정화조쇠적영향,이급 ECK 적화학조공효응。결과표명,관장기(화후0~40 d),수위협초산환원매(NR)활성화곡안선알합성매(GS)활성수밀도증가이현저하강；관장후기(화후30~40 d),곡초전안매(GOT)화곡병전안매(GPT)활성수충식밀도증가이현저강저。수위협협록소상대함량、가용성단백함량화유리안기산함량재관장중후기(화후20~40 d)수충식밀도증가이현저강저；량품충산량재7.5만주 hm–2밀도체최대치,7.5~10.5만주 hm–2밀도군체산량하강,고밀군체역발생조쇠。ECK 처리현저제고료각밀도군체관장중후기(화후20~40 d)수위협 NR 활성、GS 활성、유리안기산함량、가용성단백함량화협록소함량；현저제고료고밀군체(7.5~10.5만주 hm–2) GOT 활성화 GPT 활성；교고밀군체하(7.5~10.5만주 hm–2),중단909화준단20교각자대조적증산폭도분별위5.59%~6.63%화6.73%~8.10%。ECK 처리제고료고밀군체하옥미수위협편담대사관건매활성급기산물함량,보증밀식군체담대사정상진행,유효방지조쇠급제고산량。종상소술,채용합리적충식밀도병결합분시을왜합제가작위화북하옥미구고산재배적중요기술조시。
To explore the effects of ethylene-chlormequat-potassium (ECK) on the physiological mechanisms of nitrogen assimi-lation and early senescence in summer maize, and provide a theoretical basis for high and stable yields of summer maize under high plant density by chemical regulation technology in North China Plain, we conducted a field experiment using two varieties of Zhongdan 909 and Xundan 20 with different planting densities in 2013 and 2014. The results showed that increasing plant density significantly decreased the activities of nitrate reductase (NR) and glutamine synthetase (GS) after anthesis, glutamate oxaloacetic transaminase (GOT) activity at anthesis, and glutamate pyruvate transaminase (GPT) activity at 30 days after anthesis. The soluble protein and free amino acid contents at 20 days after anthesis, and the SPAD value at 10 days after anthesis were significantly decreased with increasing plant density. For both varieties, grain yield reached the highest under 7.5×104 plants ha–1, while de-creased under the density of ≥ 7.5×104 plants ha–1. The higher density resulted in early senescence. ECK treatment significantly increased the activities of NR, GS, and contents of free amino acid, soluble protein and SPAD value during middle and late grain filling stages. ECK treatment also significantly improved the GOT and GPT activities under 7.5×104?10.5×104 plants ha–1. Under the density ≥ 7.5×104 plant ha–1, the yields of Zhongdan 909 and Xundan 20 compared with their own control were respectively increased by 5.59%?6.63% and 6.73%?8.10%. ECK treatment significantly increased the nitrogen assimilation key enzyme acti-vity of ear leaf and its product content under different planting densities, promoted normal nitrogen assimilation and prevented early senescence under higher planting densities, therefore increased yield. Thus, an appropriate planting density combined with ECK application could be an important technique for achieving high grain yield for summer maize production in North China Plain.