【作者】 刘祥；

【导师】 张立新；

【作者基本信息】 西北农林科技大学 ， 工程硕士（专业学位）， 2022， 硕士

【摘要】 烤烟（Nicotiana tabacum L.）是陕南主要经济作物之一,对地方经济发展具有重要作用。烤烟连作、雨水淋洗及化肥大量施用等易造成土壤养分失衡,引发较严重的植株缺素症,进而影响烤烟生长发育,造成烟叶品质下降,微量元素缺乏正成为限制陕南烟区烟叶高质量发展的因素之一。因此,本研究基于陕西洛南烟区植烟土壤微量元素丰缺状况,采用叶面喷施的方式,探究了不同微肥配比(CK:H₂O 750 kg·hm^-2;T1:H₃BO₃0.260+Zn SO4·7H2O 0.800+Na2Mo O4 0.110,kg·hm^-2;T2:H3BO3 0.520+Zn SO4·7H2O0.400+Na2Mo O4 0.082,kg·hm^-2;T3:H3BO3 0.780+Zn SO4·7H2O 1.600+Na2Mo O4 0.055,kg·hm^-2;T4:H₃BO₃ 1.040+Zn SO₄·7H₂O 1.200+Na₂Mo O₄ 0.027,kg·hm^-2;T5:H₃BO₃1.300+Zn SO₄·7H₂O 2.000+Na₂Mo O₄ 0.137,kg·hm^-2)对烤烟多酚代谢、养分利用率及烤后烟叶品质的影响。主要研究结果如下:1.适量硼锌钼肥配施对烤烟旺长期烟叶多酚代谢有显著促进作用。与对照相比,不同部位烟叶黄酮、花色苷等酚类物质含量均有不同程度提高,以T5处理效果较好,其中部叶苯丙氨酸解氨酶（PAL）、肉桂酸-4-羟化酶（C4H）、4-香豆酸辅酶A连接酶（4CL）活性分别提高了49.33%、78.48%和29.34%,不同部位黄酮含量平均提高了54.03%,花色苷含量平均提高了39.74%,总酚含量平均提高了30.79%,增加了多酚累积量,同时中部叶抗坏血酸（As A）含量提高了56.64%,不同部位烟叶多酚氧化酶（PPO）活性平均下降了20.73%,减少了多酚类物质的损失。2.适量硼锌钼肥配施对烟株干物质积累量和养分利用率有一定提升作用。喷施微肥后,烟叶硼、锌、钼积累量均显著增加,氮磷钾积累量也有一定提升。与对照相比,T5处理效果较好,烟株氮素、磷素和钾素积累量分别提高了7.0%、15.86%和10.78%。3.适量硼锌钼肥配施可有效改善烟叶化学成分,提升烟叶品质。喷施微肥后,可显著提高上部叶（B2F）钾、氯含量,中部叶（C3F）总氮、钾含量及下部叶（X2F）钾含量,提高了化学品质综合评分;可显著提高上部叶（B2F）有机酸含量,中部叶（C3F）微量元素、总酚、有机酸、香气物质含量及下部叶（X2F）的微量元素和总酚含量,提升了烟叶品质。综合比较,以T5处理效果较好,不同部位烟叶常规化学品质综合评分均优于对照,硼锌钼含量分别平均提高了3.19、1.27和2.33倍,总酚、有机酸含量分别平均提高了8.63%和11.40%,中部叶（C3F）香气量提高了100.76%,产值提高了21.29%,烤烟气候斑、烟草花叶病发病率显著降低。总之,适宜浓度的硼锌钼肥配施可提高旺长期烟株养分积累量,提高烟叶多酚代谢关键酶活性,从而促进绿原酸、花色苷等多酚代谢产物合成,提高总酚含量,同时微肥通过提高烟叶抗坏血酸（As A）含量、降低多酚氧化酶（PPO）活性来抑制多酚过度氧化褐变,从而提高烟叶色泽质量和香气质量,提升烟叶经济价值,以T5处理综合效果较好。以上研究结果可为提升陕南烟区烤烟质量提供科学依据和技术支撑。更多还原

【Abstract】 Tobacco（Nicotiana tabacum L.）,as one of southern Shaanxi’s key cash crops,is crucial to the local economic development.Continuous cropping of flue-cured tobacco,rain washing and large amount of chemical fertilizer application are easy to cause soil nutrient imbalance,leading to serious plant deficiency disease,and then affect the growth and development of flue-cured tobacco,resulting in the quality decline.The scarcity of trace elements The lack of trace elements is becoming one of the factors restricting the high-quality development of tobacco leaves in southern Shaanxi.Therefore,based on the abundance and deficiency of trace elements in tobacco-growing soil in Luonan,Shaanxi province,this study investigated the effects of microfertilizer with different proportions(CK:H2O 750 kg·hm^-2;T1:H3BO3 0.260+Zn SO4·7H2O 0.800+Na2Mo O4 0.110,kg·hm^-2;T2:H3BO3 0.520+Zn SO4·7H2O 0.400+Na2Mo O4 0.082,kg·hm^-2;T3:H3BO3 0.780+Zn SO4·7H2O 1.600+Na2Mo O4 0.055,kg·hm^-2;T4:H3BO3 1.040+Zn SO4·7H2O 1.200+Na2Mo O4 0.027,kg·hm^-2;T5:H3BO3 1.300+Zn SO4·7H2O 2.000+Na2Mo O4 0.137,kg·hm^-2)on polyphenol metabolism,nutrient utilization and quality of cured tobacco leaves.The main results are as follows:1.Combined application of appropriate amount of boron,zinc and molybdenum fertilizer can greatly boost polyphenol metabolism in flue-cured tobacco.Compared with the control,the contents of flavonoids,anthocyanins and other phenolic compounds in different parts of tobacco leaves were increased to different degrees,and T5 treatment had better effect.The activities of phenylalanine ammoniase（PAL）,cinnamate 4-hydroxylase（C4H）and 4-coumaric acid coenzyme A ligase（4CL）in the leaves were increased by 49.33%,78.48%and29.34%,respectively.The contents of flavonoids,anthocyanins and total phenols in different parts were increased by 54.03%,39.74%and 30.79%on average,which increased the amount of polyphenols accumulated.Meanwhile,the content of ascorbic acid in middle leaves increased by 56.64%,and the activity of polyphenol oxidase（PPO）in different tobacco leaves decreased by 20.73%on average,which reduced the loss of polyphenols.2.Combined application of appropriate amount of boron,zinc and molybdenum fertilizer can improve dry matter accumulation and nutrient utilization efficiency of tobacco plant.After spraying micro fertilizer,the accumulation of boron,zinc and molybdenum in tobacco leaves increased significantly,and the accumulation of nitrogen,phosphorus and potassium also increased to a certain extent.Compared with the control,T5 treatment had better effect,and the accumulation of nitrogen,phosphorus and potassium in tobacco plant increased by 7.0%,15.86%and 10.78%,respectively.3.Combined application of appropriate amount of boron,zinc and molybdenum fertilizer can effectively improve chemical composition and quality of tobacco leaves.After spraying microfertilizer,the contents of potassium and chlorine in upper leaves（B2F）,total nitrogen and potassium in middle leaves（C3F）and potassium in lower leaves（X2F）were significantly increased,which improved the comprehensive score of chemical composition.The contents of organic acids in upper leaf（B2F）,trace elements,total phenols,organic acids and aroma substances in middle leaf（C3F）and trace elements and total phenols in lower leaf（X2F）were significantly increased,which improved the quality of tobacco leaves.Comprehensive comparison showed that T5 treatment had better effect,and the comprehensive score of conventional chemical quality of tobacco leaves in different parts was better than the control.The content of boron,zinc and molybdenum increased by 3.19,1.27and 2.33 times on average,the content of total phenols and organic acids increased by 8.63%and 11.40%on average,and the aroma content of middle leaves（C3F）increased by 100.76%.The output value increased by 21.29%,and the incidence of flue-cured tobacco climatic spot and tobacco Mosaic decreased significantly.In general,the combination of boron,zinc and molybdenum fertilizer with appropriate concentration can increase the nutrient accumulation of tobacco plants in flourishing period,improve the activities of key enzymes in polyphenol metabolism of tobacco leaves,and promote the synthesis of polyphenol metabolites such as chlorogenic acid and anthocyanin,and increase the total phenol content.At the same time,micro fertilizer could prevent excessive oxidation and browning of polyphenols by raising ascorbic acid（As A）content and decreasing polyphenol oxidase（PPO）activity.Therefore,it can improve the quality of tobacco color and aroma,and enhance the economic value of tobacco.The above research results can give a scientific foundation and technological support for improving flue-cured tobacco quality in southern Shaanxi.更多还原