【作者】 王学龙；

【导师】 涂书新；

【作者基本信息】 华中农业大学 ， 植物营养学， 2012， 博士

【摘要】 烟碱含量是重要的烤烟品质指标。矿质营养是影响烤烟烟碱含量的关键因素之一,因此,开展矿质营养对烟碱合成及其生理机制的研究对于开发有效的烟碱调控技术措施意义重大。本项研究旨在解决鄂西北部分烟区烤烟烟碱含量偏高、化学协调性不够等问题,通过土壤盆栽试验、水培试验、15N示踪技术、田间试验与示范多种措施,探讨了磷钾配比、氮素形态、硼(B)水平对烤烟打顶后7d较短时间内烟碱合成和烟叶品质形成的影响,研究了它们调控烟碱、影响烟叶品质的作用机理,取得的重要研究结果如下：1.采用土壤盆栽试验研究了不同磷钾营养水平对烤烟打顶前后烟碱合成及养分吸收和分配的影响。研究结果表明,增施磷肥能增加烤烟地上部分烟碱的积累8%-69%、相应增加根部腐胺-N-甲基转移酶(PMT)、精氨酸脱羧酶(ADC)、鸟氨酸脱羧酶(ODC)的活性,并增加地上部对氮、磷、钾的吸收。而增施钾肥则降低烤烟地上部分烟碱的积累8%-45%、降低根部PMT、ADC和ODC活性,降低地上部氮和磷的吸收,但增加地上部钾的吸收。结果说明,烤烟磷钾营养通过调控烟碱合成酶活性及影响养分积累从而调控烤烟烟碱的合成与积累。2.采用土壤盆栽试验研究了不同氮素形态及其配合对烤烟烟碱含量及烟碱合成相关酶活性的影响。结果表明,100%铵态氮最有利于合成烟碱,而50%硝态氮+50%铵态氮或30%有机肥+35%硝态氮+35%铵态氮则有利于控制烟碱含量。打顶后中、上部叶片的烟碱含量,以100%铵态氮最高、50%硝态氮+50%铵态氮或30%有机肥+35%硝态氮+35%铵态氮最低。打顶后中、上部叶片烟碱含量的增幅,以及根部PMT、ODC、ADC活性的增幅均以50%硝态氮+50%铵态氮最小。3、土壤盆栽试验表明,烤烟各部位叶片N含量均随着施用的硝态氮比例的上升而提高。烤烟根、茎、叶的含氮量以100%硝态氮处理最高,100%铵态氮处理最低；100%硝态氮、30%有机肥+35%硝态氮+35%铵态氮较100%铵态氮更有利于烤烟各部位叶片对钾的吸收；100%酰胺态氮和30%有机肥+35%硝态氮+35%铵态氮促进烤烟叶部干物质积累效果明显,而100%的硝态氮和100%铵态氮促进干物质积累效果最差。4、15N同位素示踪盆栽试验研究发现,烤烟氮肥利用率以100%硝态氮和30%有机肥+35%硝态氮+35%铵态氮处理最高,达到38%,而以100%铵态氮处理最低,只有25%；各部位叶片所吸收的肥料氮占总氮含量的比例均为100%硝态氮处理最高,100%铵态氮处理居中,而以30%有机肥+35%硝态氮+35%铵态氮处理最低。5、烤烟叶片淀粉酶(AMS)、硝酸还原酶(NR)、蔗糖转化酶(INV)、谷氨酰胺合成酶(GS)的活性在打顶后均呈下降趋势。AMS、NR酶活在打顶前后均以100%硝态氮处理最高,100%铵态氮处理最低。GS活性烤烟打顶前后均以100%铵态氮最高,50%铵态氮和30%有机肥+35%硝态氮+35%铵态氮较低。INV活性打顶后以100%铵态氮和30%有机肥+35%硝态氮+35%铵态氮降幅较为剧烈。6、烤烟水培试验表明,在B水平10μmo1/L、50gmo1/L、200μmo1/L时,中烟100打顶前后叶片的烟碱含量以及增幅,均以200μmo1/L最高,其打顶前后叶部烟碱的含量均随B水平的升高而增加。而K326、鄂烟1号打顶前后叶部烟碱的含量,以及烟碱含量的增幅均以10μmol/L最高；B水平变化对各品种根部烟碱合成相关酶(PMT、ODC、ADC)活性也有一定的影响,但规律性不明显。7、水培实验表明,随B水平变化,各品种打顶后叶部NR、INV、谷氨酰胺合成酶(GS)活性、叶绿素含量、净光合速率仍呈上升趋势,而AMS活性、叶片胞间CO2浓度呈下降趋势。总体而言,打顶效应对这些生理指标的影响要大于B水平的变化。8、烤烟的N、B、K积累主要以叶部为主。中烟100、K326、鄂烟1号对N、B的吸收能力都较强,叶片中N、B的含量随B水平的升高而增加,鄂烟1号叶部B积累量明显低于中烟100和K326。各品种地上部分全叶的钾含量均以B水平50μmo1/L最高,200μmol/L最低。9、叶部烟碱含量与氮肥利用率、叶部淀粉酶、硝酸还原酶、转化酶活性呈显著负相关,与根部PMT、ODC、ADC活性、胞间CO2浓度显著正相关；叶部烟碱含量还与净光合速率、叶绿素含量呈负相关,但均不显著。10、在大田条件下,研究了叶面调理剂的不同施用方法对烤烟的施用效果。田间试验示范表明,所研制的叶面调理剂具有促进烟株生长,缩短大田生育期,增强烟株抗逆性能,提高经济效益和改善烟叶品质的效果。更多还原

【Abstract】 Nicotine content is one of the important indicators for quality of flue-cured tobacco. As mineral nutrition is the key factor to influence nicotine content of flue-cured tobacco, understanding of the role and its physiological mechanism of mineral nutrients in nicotine synthesis is significant to develop an effective nicotine regulation technology. Aimed to solve the problems of high level nicotine content of flue-cured tobacco (FCT) and bad chemical coordination of FCT quality in tobacco production area of northwest Hubei Province, this study studied the effects of phosphorus and potassium nutrition levels, nitrogen fertilizer forms, and boron nutrition level on nicotine synthesis and formation of tobacco quality during the topping stage by use of soil pot experiments, hydroponic experiments,15N tracing experiments, and field experiments. The main results were summarized as follows:1. The effects of P and K level on tobacco’s nicotine synthesis, nutrient uptake and distribution before and after topping were studied with soil-pot experiment. The results suggested that P fertilizer improved nicotine accumulation8%-69%of upper parts of FCT, correspondingly increased the activity of putrescine-N-methyltransferase (PMT), arginine decarboxylase (ADC), and ornithine decarboxylase (ODC) in roots, and the intake of N, P and K. Meanwhile, the increase of potash fertilizer decreased the nicotine accumulation by8%-45%, the activity of PMT, ADC and ODC in roots, and the uptake of N and P, but increased the uptake of K. The result indicated that the P/K nutrition of FCT could control the nicotine synthesis and accumulation through the regulation of nicotine synthase activity and the influence of nutrition accumulation.2. The influence of different N fertilizer forms and its coordination to nicotine content and relevant nicotine synthase activity were investigated with soil-pot experiment. The results indicated that100%ammonium-N was beneficial to nicotine accumulation most, while50%nitrate-N/50%ammonium-N or30%manure/35%nitrate-N/35%ammonium-N was beneficial to control the nicotine content. After topping, the nicotine content of middle and upper leaves of FCT was the highest with100%ammonium-N while the lowest with50%nitrate-N/50%ammonium-N or30%manure/35%nitrate-N/35%ammonium-N. After topping, the increase amplitude of middle and upper leaves’ nicotine content and the activity of PMT, ODC and ADC in roots was the lowest with50%nitrate-N/50%ammonium-N.3. The soil-pot experiment indicated that the N content in all parts of FCTleaves was increased along with the increase of nitrate nitrogen. The N contents in root, stem and leaf were the highest with the application of100%nitrate-N, and the lowest with100%ammonium-N. There was a better uptake of K for all leaves with100%nitrate-N, and30%manure/35%nitrate-N/35%ammonium-N than100%ammonium-N, and an obvious effect in dry matter accumulation in leaves with100%amide N, and30%manure/35%nitrate-N/35%ammonium-N. The worst effects for dry matter accumulation were with100%nitrate-N and100%ammonium-N.4. The soil pot research with15N isotope tracer found that the utilization of N fertilizer was highest with the application of100%nitrate-N and30%manure/35%nitrate-N/35%ammonium-N, up to38%, while lowest with100%ammonium-N, down to25%only. The N nutrition absorbed by all leaves in the whole N content was the highest with100%nitrate-N, middle with100%ammonium-N, and the lowest with30%manure/35%nitrate-N/35%ammonium-N.5. The activity of amylase (AMS), nitrate reductase (NR), sucrose invertase (INV) and glutamine synthetase (GS) was on a declining curve in leaves after topping. The enzyme activity of AMS and NR was the highest and lowest with the application of100%nitrate-N and100%ammonium-N individually before and after topping. The activity of GS was the highest with100%nitrate-N, and the lowest with50%ammonium-N and30%manure/35%nitrate-N/35%ammonium-N before and after topping. The activity of INV had a sharp reduction after topping with100%ammonium-N, and30%manure/35%nitrate-N/35%ammonium-N.6. The hydroponic experiments of FCT showed that the leaves’nicotine content and amplification was the highest with200μmol/L B treatment, and the leaves’ nicotine content increased with the rise of B level before and after topping of variety Zhongyan100. However, for variety K326and Eyan1, the leaves’nicotine content and its amplification were the highest with10μmol/L B treatment. The change of level B had a certain influence on the activity of nicotine synthesis enzymes (PMT, ODC and ADC) for different varieties.7. The hydroponic experiment showed that along with the change of B level, the activity of NR, INV, and glutamine synthetase (GS), the chlorophyll content, and the net photosynthetic rate were in a rise curve to different varieties in leaves after topping, while the activity of AMS and the concentration of CO2in leaves intercellular were in a declining curve. In general, the influence of topping to those physical signs was heavier than the change of level B. 8. The accumulation of N, B and K was mainly in leaves of FCT. Zhongyan100, K326, Eyan1had a strong ability of N and B uptake, and the N and B content in leaves increased along with the increase of B level. However, the accumulation B in leaves of Eyan1was obviously lower than that of Zhongyan100and K326. The whole leaves’K to different varieties above-ground was the highest with B level of50μmol/L, and the lowest with B level of200μmol/L.9. The leaves’ nicotine content had an obvious negative correlation with the utilization rate of N fertilizer, amylase, nitrate reductase and invertase activity, and an obvious positive correlation with PMT, ODC, ADC activity and CO2concentration in leaves intercellular in roots. The leaves’ nicotine content also had a negative correlation with net photosynthetic rate and chlorophyll content, but not obviously.10. In field conditions, the research of application effect with several methods of the foliage conditioner was carried out. The demonstration of field experiment showed that the foliage conditioners in research had an effect in promoting the tobacco-plant growth, shortening the growing stage, strengthening the tobacco-plant’s resisting performance, and improving the economic benefit and tobacco quality.更多还原