CAJ | 학술논문

【目的】苗期棉花根系发育缓慢，吸收能力弱，根系吸收的氮素不能满足棉株生长发育的需要，很容易出现僵苗、弱苗。叶面施氮可以及时补充氮素营养，解决棉花苗期阶段性营养不足的问题。本研究利用15 N同位素示踪技术研究喷施尿素对棉花苗期氮素吸收利用及生理生化特性的影响，以明确棉花苗期叶面喷施尿素的适宜浓度，了解其促进棉花生长发育的机理。【方法】本试验选用黄河流域常规栽培品种中棉所79为试验材料，采用随机区组设计，在棉花苗期叶面喷施0.5%、1%和2%的15 N-尿素溶液，以喷清水为对照，调查了尿素不同喷施浓度棉花氮素的吸收利用及生理生化特性。【结果】1）叶面喷施15 N-尿素能显著提高棉株15 N含量，各施氮处理棉株内15 N含量随时间的变化趋势一致，即叶面喷施后296 h之间，逐渐升高，96 h达到最高，此后出现下降。2）棉株可以快速吸收叶面喷施的15 N-尿素，各处理棉株叶面氮素平均吸收速率的变化趋势一致，因中午气孔关闭，24 h出现降低；46h达到最大，期间急剧上升；68h急剧下降，812h下降也较快，12h后缓慢下降。012h平均吸收速率非常高，为0.230.29 mg/（g·h）。棉株对于叶施氮素的吸收主要出现在喷施后12 h之内。3）15 N-尿素浓度为0.5%、1%时，叶面吸收显著促进了根系氮素吸收，且根系吸收的氮很快被转运到地上部分。4）1%尿素喷施浓度内，硝酸还原酶、谷氨酰胺合成酶活性，叶绿素含量的变化趋势一致，均随尿素喷施浓度的增加而提高，在喷施浓度为1%时达到峰值，超过1%后开始下降。【结论】叶面尿素喷施浓度在0.5%2%之间均能显著提高棉株15 N含量，促进棉株的氮素代谢，以1%效果最佳。棉株对于喷施氮素的吸收主要发生在喷施后012 h，平均吸收速率为0.230.29 mg/（ g·h），96 h棉株中15 N含量达到最高。棉花叶面施氮促进了根系对氮素的吸收。叶面施氮主要通过增强硝酸还原酶、谷氨酰胺合成酶活性，提高叶绿素含量，增加叶面积，促进叶片的光合作用，以此提高氮素利用效率，增加棉花株高和总生物量。【目的】苗期棉花根繫髮育緩慢，吸收能力弱，根繫吸收的氮素不能滿足棉株生長髮育的需要，很容易齣現僵苗、弱苗。葉麵施氮可以及時補充氮素營養，解決棉花苗期階段性營養不足的問題。本研究利用15 N同位素示蹤技術研究噴施尿素對棉花苗期氮素吸收利用及生理生化特性的影響，以明確棉花苗期葉麵噴施尿素的適宜濃度，瞭解其促進棉花生長髮育的機理。【方法】本試驗選用黃河流域常規栽培品種中棉所79為試驗材料，採用隨機區組設計，在棉花苗期葉麵噴施0.5%、1%和2%的15 N-尿素溶液，以噴清水為對照，調查瞭尿素不同噴施濃度棉花氮素的吸收利用及生理生化特性。【結果】1）葉麵噴施15 N-尿素能顯著提高棉株15 N含量，各施氮處理棉株內15 N含量隨時間的變化趨勢一緻，即葉麵噴施後296 h之間，逐漸升高，96 h達到最高，此後齣現下降。2）棉株可以快速吸收葉麵噴施的15 N-尿素，各處理棉株葉麵氮素平均吸收速率的變化趨勢一緻，因中午氣孔關閉，24 h齣現降低；46h達到最大，期間急劇上升；68h急劇下降，812h下降也較快，12h後緩慢下降。012h平均吸收速率非常高，為0.230.29 mg/（g·h）。棉株對于葉施氮素的吸收主要齣現在噴施後12 h之內。3）15 N-尿素濃度為0.5%、1%時，葉麵吸收顯著促進瞭根繫氮素吸收，且根繫吸收的氮很快被轉運到地上部分。4）1%尿素噴施濃度內，硝痠還原酶、穀氨酰胺閤成酶活性，葉綠素含量的變化趨勢一緻，均隨尿素噴施濃度的增加而提高，在噴施濃度為1%時達到峰值，超過1%後開始下降。【結論】葉麵尿素噴施濃度在0.5%2%之間均能顯著提高棉株15 N含量，促進棉株的氮素代謝，以1%效果最佳。棉株對于噴施氮素的吸收主要髮生在噴施後012 h，平均吸收速率為0.230.29 mg/（ g·h），96 h棉株中15 N含量達到最高。棉花葉麵施氮促進瞭根繫對氮素的吸收。葉麵施氮主要通過增彊硝痠還原酶、穀氨酰胺閤成酶活性，提高葉綠素含量，增加葉麵積，促進葉片的光閤作用，以此提高氮素利用效率，增加棉花株高和總生物量。
【목적】묘기면화근계발육완만，흡수능력약，근계흡수적담소불능만족면주생장발육적수요，흔용역출현강묘、약묘。협면시담가이급시보충담소영양，해결면화묘기계단성영양불족적문제。본연구이용15 N동위소시종기술연구분시뇨소대면화묘기담소흡수이용급생리생화특성적영향，이명학면화묘기협면분시뇨소적괄의농도，료해기촉진면화생장발육적궤리。【방법】본시험선용황하류역상규재배품충중면소79위시험재료，채용수궤구조설계，재면화묘기협면분시0.5%、1%화2%적15 N-뇨소용액，이분청수위대조，조사료뇨소불동분시농도면화담소적흡수이용급생리생화특성。【결과】1）협면분시15 N-뇨소능현저제고면주15 N함량，각시담처리면주내15 N함량수시간적변화추세일치，즉협면분시후296 h지간，축점승고，96 h체도최고，차후출현하강。2）면주가이쾌속흡수협면분시적15 N-뇨소，각처리면주협면담소평균흡수속솔적변화추세일치，인중오기공관폐，24 h출현강저；46h체도최대，기간급극상승；68h급극하강，812h하강야교쾌，12h후완만하강。012h평균흡수속솔비상고，위0.230.29 mg/（g·h）。면주대우협시담소적흡수주요출현재분시후12 h지내。3）15 N-뇨소농도위0.5%、1%시，협면흡수현저촉진료근계담소흡수，차근계흡수적담흔쾌피전운도지상부분。4）1%뇨소분시농도내，초산환원매、곡안선알합성매활성，협록소함량적변화추세일치，균수뇨소분시농도적증가이제고，재분시농도위1%시체도봉치，초과1%후개시하강。【결론】협면뇨소분시농도재0.5%2%지간균능현저제고면주15 N함량，촉진면주적담소대사，이1%효과최가。면주대우분시담소적흡수주요발생재분시후012 h，평균흡수속솔위0.230.29 mg/（ g·h），96 h면주중15 N함량체도최고。면화협면시담촉진료근계대담소적흡수。협면시담주요통과증강초산환원매、곡안선알합성매활성，제고협록소함량，증가협면적，촉진협편적광합작용，이차제고담소이용효솔，증가면화주고화총생물량。
Objectives]Cotton roots grow s1ow at the seed1ing stage,so the absorPtion of nitrogen by roots can not meet the needs of growth and deve1oPment of cotton P1ants,dead1ock or weak seed1ings are often haPPened as a resu1t. Fo1iar nitrogen aPP1ication can reP1enish nitrogen nutrition in time and so1ve Prob1em of Periodic innutrition at the seed1ing stage. In order to c1arify the oPtimum urea concentration of fo1iar sPraying and understand its mechanism of Promoting cotton growth and deve1oPment,the 15 N isotoPe tracer technique was used to investigate effects of fo1iage sPraying urea on nitrogen uPtake and uti1ization,and Physio1ogica1 and biochemica1 characteristics of cotton.[Methods]A fie1d exPeriment with randomized comP1ete-b1ock design were conducted with cotton cu1tivar CCRI79 as an exPerimenta1 materia1. Four fo1iage sPraying concentration of 15 N-urea so1ution:0%,0. 5%,1%and 2% were sPrayed at the seed1ing stage of cotton seed1ings. The uPtake and uti1ization,and the Physio1ogica1 and biochemica1 characteristics of cotton were investigated.[Results]1)The fo1iage sPraying of 15N-urea can significant1y imProve the 15 N content of cotton P1ants. The 15 N uPtake by cotton 1eaves is increased gradua11y from 2 to 96 h after sPraying,then dec1ined. 2)The sPrayed15 N-urea can be absorbed quick1y by cotton P1ants,and the average N absorPtion rates with time are consistent in a11 the treatments. The main uPtake of the sPrayed N is occured within 12 h. . The absorPtion rates sharP1y rise to the highest from 4-6 h after sPraying,then dec1ine sharP1y from 6-8 h,keeP fast from 8-12 h and s1owdown after 12 h. The average nitrogen absorPtion rates from 0-12 h is 0. 23-0. 29 mg/(g·h). 3)The fo1iar suPP1ement of N nutrition can significant1y Promote the uPtake and uP transPort of the nitrogen absorbed by roots under the treatments of 0. 5% and 1% urea concentrations. 4)Under the urea sPraying concentrations from 0% to 1%,the nitrate reductase activity,g1utamine synthetase activity and ch1oroPhy11 content are increased with the increase of sPraying concentrations. The Physio1ogica1 and biochemica1 indexes are the highest under the treatment of 1% concentration.[Conclusions]The fo1iar sPraying of urea can imProve the N nutrition of cotton seed1ings significant1y by both the direct absorPtion of fo1iar sPrayed N and acce1erated N uPtake and uP transPort by root. The uPtakes of sPrayed 15 N by cotton P1ants are main1y occurred within the 12 hours after sPraying,with the average absorPtion rates of 0. 231-0. 293 mg/( g·h),dePending on the sPraying concentrations. The contents of 15 N in cotton P1ants keeP increasing unti1 the 96 hours after sPraying. The fo1iar suPP1ement of N nutrition Promote Photosynthesis by increasing the activities of nitrate reductase and g1utamine synthetase,increasing the ch1oroPhy11 content,and imProve 1eaf area of cotton P1ants. The suitab1e sPray concentration is 1% of urea at the seed1ing stage of cotton.