不同叶位烟叶生物学特性差异比较研究

发布时间：2019-01-17 11:23

【摘要】：烟草(Nicotiana tabacum L.)是我国重要经济作物,为了分析探讨上部烟叶偏厚偏硬的原因,本论文采用石蜡制片显微技术,对种植在陕西环秦岭洛南地区的主栽烤烟品种云烟99与秦烟96以及南郑地区主栽烤烟品种云烟99不同叶位、不同成熟度叶片的解剖结构进行了比较研究,为解释上部叶偏厚的原因提供解剖学依据;并且通过测定洛南地区云烟99不同叶位烟草叶片果胶多聚半乳糖醛酸酶、纤维素酶以及过氧化物酶活性,以期为上部叶偏硬现象提供相关代谢酶依据。主要试验结果如下:解剖学观察结果表明:烟草下、中、上三个叶位叶片的解剖学规律基本一致,表现为叶片厚度、栅栏组织厚度、海绵组织厚度、单位长度栅栏细胞数均随着成熟度增加逐渐减小,且三个叶位的叶片海绵组织变薄的速度都较栅栏组织更快。但不同叶位烟叶解剖学差异表现为上部叶的栅栏组织厚度、海绵组织厚度与上表皮厚度均比下部叶和中部叶厚;且上部叶随成熟度变薄的速度较中部叶和下部叶慢,这是导致上部叶较厚的解剖学原因。不同品种烟草叶片组织解剖学规律差异表现为:云烟99三个叶位叶片较秦烟96厚,但随成熟度增加不同叶位烟叶厚度的减小幅度存在品种间差异,云烟99上部叶与下部叶片厚度的减小幅度小于秦烟96但中部叶片厚度的减小幅度大于秦烟96。不同地区烟草叶片组织解剖学规律差异表现为:南郑地区各叶位烟叶的叶片厚度、栅栏组织厚度、海绵组织厚度、上表皮厚度、单位长度栅栏组织细胞数均大于洛南地区。相关生理代谢酶指标测定结果表明:三种测试酶活性随成熟度的变化趋势不同叶位间表现相似,均表现为随成熟度的增加多聚半乳糖醛酸酶的活性与纤维素酶活性增强,而过氧化物酶活性降低。相同成熟度下,三种测试酶的活性大小依不同叶位存在差异,上部烟叶的多聚半乳糖醛酸酶活性与纤维素酶活性最小、过氧化物酶活性最强,说明上部叶中细胞的果胶与纤维素降解能力弱、木质素合成能力强,这是导致上部叶较中下部叶偏硬的代谢酶原因。综合试验结果可知,上部叶栅栏组织、海绵组织厚度比下部叶和中部叶厚且上部叶片厚度随成熟度的增加而变薄的速度较中部叶和下部叶慢,是导致上部叶较厚的原因。上部叶位烟叶果胶与纤维素分解较慢但木质素合成较旺盛是上部烟叶偏硬的重要生理原因,且上部叶的上表皮厚度均显著大于下部叶也是导致上部叶偏厚偏硬的原因之一。
[Abstract]:Tobacco (Nicotiana tabacum L.) It is an important cash crop in China. In order to analyze the reasons of thick and hard upper tobacco leaves, this paper adopts paraffin wax microtechnology. The anatomical structure of the main flue-cured tobacco varieties Yunyan 99 and Qinyan 96 planted in Luonan area of Qinling Mountains, Shaanxi Province, and Yunyan 99, the main flue-cured tobacco variety in Nanzheng area, were studied in different leaf position and maturity. To provide anatomic basis for explaining the cause of upper leaf thickness. The activities of Pectin polygalacturonidase, cellulase and peroxidase in tobacco leaves of Yunyan 99 in Luonan area were determined in order to provide relevant metabolic enzyme basis for the phenomenon of upper leaf stiffening. The main results were as follows: anatomical observation showed that the anatomical characteristics of the three leaves under tobacco, middle and upper leaves were basically the same, including leaf thickness, palisade tissue thickness, sponge tissue thickness, and so on. The number of palisade cells per unit length decreased gradually with the increase of maturity, and the thinning rate of spongy tissue of three leaf positions was faster than that of palisade tissue. However, the anatomical differences of different leaf positions were the thickness of palisade tissue of upper leaf, the thickness of sponge tissue and upper epidermis were thicker than those of lower leaf and middle leaf. The thinning rate of upper leaf with maturity is slower than that of middle leaf and lower leaf, which is the anatomic cause of thicker upper leaf. The differences of leaf tissue anatomy of different varieties of tobacco were as follows: Yunyan 99 leaves were thicker than Qinyan 96 leaves, but with the increase of maturity, there were differences between varieties in the decreasing range of leaf thickness of different leaf positions. The thickness of upper leaf and lower leaf of Yunyan 99 was smaller than that of Qinyan 96, but the thickness of middle leaf was larger than that of Qinyan 96. The differences of leaf tissue anatomy in different areas were as follows: the thickness of leaf, palisade tissue, sponge tissue, upper epidermis and palisade cells per unit length of tobacco in Nanzheng area were all larger than those in Luonan area. The results showed that the activity of the three tested enzymes was similar with maturity, and the activity of galacturonidase and cellulase increased with the increase of maturity, and the activity of galacturonidase and cellulase increased with the increase of maturity, and the activity of galacturonidase and cellulase increased with the increase of maturity. The activity of peroxidase decreased. At the same maturity, the activity of the three tested enzymes varied according to different leaf position. The polygalacturonase activity and cellulase activity of the upper tobacco leaf were the lowest, and the peroxidase activity was the highest. The results showed that the degradation ability of pectin and cellulose in the upper leaves was weak, and the lignin synthesis ability was strong, which was the reason why the upper leaves were harder than those in the middle and lower leaves. The results showed that the thickness of upper palisade tissue and spongy tissue was thicker than that of lower and middle leaves, and the thickness of upper leaves was thicker than that of middle leaves and lower leaves with the increase of maturity, which was the cause of thicker upper leaves. The slow decomposition of pectin and cellulose in upper leaves and the strong lignin synthesis were the important physiological reasons for the hardness of upper leaves, and the thickness of upper epidermis of upper leaves was significantly larger than that of lower leaves, which also contributed to the thickening and hardening of upper leaves.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S572

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