【作者】 刘金凤；

【导师】 谭启玲；

【作者基本信息】 华中农业大学 ， 植物营养学， 2006， 硕士

【摘要】 采用盆栽、水培和根箱试验，研究壳聚糖对蔬菜产量品质、蔬菜根系生长及土壤理化性状的影响。主要结论如下：1．壳聚糖能提高蔬菜的产量。施用壳聚糖处理能提高樱桃番茄的产量16.2％～20.0％，提高番茄产量24.6％～26.1％，提高盆栽小白菜产量3.6％～29.4％，适宜浓度的壳聚糖也可以提高水培小白菜产量。2．壳聚糖能改善蔬菜品质。施用壳聚糖在提高蔬菜产量的同时，还改善了其品质。壳聚糖能显著提高番茄果实中Vc的含量，并调节果实中的糖酸比，使之口感更佳。且施用壳聚糖处理的番茄果实果型更加美观。盆栽试验中，施肥+壳聚糖处理比单施肥料处理小白菜叶片Vc含量提高18.2％，糖酸比提高24.8％，硝态氮含量降低12.9％；水培试验中，用浓度为2mg／L壳聚糖处理小白菜叶片Vc含量提高3.1％，糖酸提高25.5％，硝态氮含量降低26.6％。3．壳聚糖能促进蔬菜营养生长和生殖生长。壳聚糖可以促进蔬菜地上部的生长，尤其能促进蔬菜苗期生长。在番茄盛花期到来之前，施用壳聚糖能使番茄株高增长速度比对照快一倍，茎较对照粗壮，叶色也较浓绿。壳聚糖处理的樱桃番茄和水培小白菜叶片叶绿素含量也显著提高。到生殖生长时期，施用壳聚糖处理的蔬菜开花多、座果率高，成熟期可提早两到三天。4．壳聚糖促进了蔬菜根系生长，增加了蔬菜根冠比，增加了水培小白菜根系活跃吸收面积。施用壳聚糖不仅促进蔬菜地上部生长，而且对蔬菜根系生长促进作用尤为显著。施用壳聚糖处理的水培小白菜根冠比、根长和根重较对照均有所增加，尤其是壳聚糖浓度为2mg／L时，小白菜根系的侧根较多，根颜色发亮，根系生长态势良好；根系活跃吸收面积增加35.8％，根系的比表面积和总吸收面积也分别增加19.7％和49.8％。但壳聚糖浓度过高时，则会抑制小白菜根系的生长。由根箱试验可以得出，施用壳聚糖处理的番茄、黄瓜、小白菜、苋菜、辣椒五种蔬菜的根冠比提高了15％～60％；根系密度也有所增加，尤其是番茄和黄瓜，效果十分显著。5．壳聚糖能改善土壤物理性质。壳聚糖可以增加未种植蔬菜黄棕壤和潮土的总孔隙度，且作用时间越长增加量越大。壳聚糖可以增加土壤毛管孔隙度，增强土壤保持水分的能力，尤其是在种作物的条件下。壳聚糖可以增加黄棕壤粒径较大的微团聚体含量，减少粒径较小微团聚体含量，改善黄棕壤土壤结构。6．壳聚糖促进了土壤有机质分解。施用壳聚糖可以促进种蔬菜的黄棕壤有机质的分解。对于未种蔬菜土壤，壳聚糖对土壤有机质的作用与土壤类型有关。施用壳聚糖促进贫瘠的黄棕壤土壤有机质的分解；施用壳聚糖还增加了肥力较高的潮土土壤有机质含量。7．壳聚糖提高了土壤速效养分含量，促进了蔬菜对养分的吸收。壳聚糖处理可以增加未种蔬菜土壤速效氮的含量。肥料+壳聚糖处理的未种蔬菜黄棕壤和潮土两种土壤的速效氮含量增加量与单施肥料处理相比，差异分别达到极显著和显著水平。对于生物量较小的种蔬菜土壤和根箱非根际土，壳聚糖使其速效氮含量均有所增加。而对于种蔬菜土壤和根箱根际土，施肥+壳聚糖处理可使其速效氮含量减少。且使蔬菜养分含量增加。土壤速效磷变化趋势与速效氮基本一致，只是幅度略小。对于土壤速效钾含量而言，无论是否施肥条件下，壳聚糖处理均可提高未种蔬菜的黄棕壤和潮土的速效钾含量。但对于种蔬菜土壤，经壳聚糖处理后速效钾含量则有降低的趋势。说明壳聚糖不仅可以增加土壤速效养分含量，还可以促进蔬菜对土壤养分的吸收，从而增加土壤肥力，提高肥料利用率。8．壳聚糖增强了蔬菜抗逆性。壳聚糖处理可提高樱桃番茄和番茄脯氨酸的含量，降低其丙二醛和电解质渗透率含量，其中樱桃番茄脯氨酸增加量达到显著性水平，从而增强了它们抗高温能力；对于小白菜，壳聚糖处理可以显著提高其叶片中脯氨酸的含量，降低丙二醛的含量，从而提高其抗寒能力。更多还原

【Abstract】 The pot, root box and solution cultivation were conducted to study the effects of chitosan on vegetables yields, qualities, root growth. soil physical properties and chemical characteristics. The resuilts show that:1. Chitosan treatment can increas vegetables yields. Application of chitosan increased the yield of cherry tomato, tomato, and Chinese cabbagge by 16. 2%—20.0%, 24.6%-26.1%, and 3.6%-29.4%, separately.2. Chitosan application improved qualities of vegetables. Application of chitosan increased the Vc content and the brix/acid ratio in vegetables. The pot cultivation showed that fertilizer-chitosan treatment increased content of Vc, brix/acid ratio and decreased NO₃-N concent in Chinese cabbage. The solution cultivation also showed that application of 2mg/L chitosan increased concent of Vc and brix/acid ratio in Chinese cabbage by 3.1% and 25.5%, separately, but decreased concent of NO₃-N by 26.6%.3. Chitosan treatment can improve vegetables growth. Chitosan treatment improved growth of vegetable shoot, especially seedling growth. The growth speed of plant height of tomato by using chitosan was two times than control before the flowering period in cherry tomato and tomato, the stem was thicker than control, the content of chlorophyll was increased significantly, the number of flower and fruit were more than control, and the date of maturity was advanced two or three days.4. Chitosan application inproved the root growth, increased the active absorption area and the ratio of root-shoot. The solution cultural cultivation indicated that Chitosan application increased the length and weight of root and the ratio of root-shoot, and the effects were greater at 2mg/L chitosan concent. But when the chitosan concent was too high, the root growth was inhibited. Chitosan also increased the root-shoot ratio of the five vegetables: tomato, cucumber, Chinese cabbage, amaranth and pepper in root box cultivation, the root-shoot ratio of five vegetables were increased 15%-60%; their root density were also increased, especially in tomato and cucumber.5. Chitoan treatment can amend soil physical properties. Application of chitoan improved the total porosity in yellow brown soil and flavor-aquic soil. It also increased the soil capillary porosity, especially in the condition of planting vegetables. The ability of holding water and the bigger diameter micro-aggregate were enhanced, but decreased content of the smaller diameter.6. Chitosan facilitated the decomposition of soil organic matter. Chitosan facilitated the decomposition of soil organic matter. For no planting soil, the effects of chitosan were related with soil species. Chitosan faciliated the decomposition of organic matte in yellow brown soil, but increased the organic content in flavor-aquic soil.7. Chitosan elevated available nutrition contents in soil and faeiliated nutrition absorption by vegetable. Chitosan increased the available N content in no planting soil. Compared with the control, fertilizer-chitosan treatment significantly increased alkali hydrolysable N in both yellow brown soil and flavor-aquic soils. The content of alkali hydrolysable N also was increased in planting soil with small biomass and bulk soil with in root box culture. But the content of alkali hydrolysable N also was reduced in planting soil and rhizosphere soil in root box culture. The nutrition contents of vegetable were increased. The change trend of soil available P was consistent with alkali hydrolysable N, but its range was smaller. The available K contents in soil, with or without fertilizer, were elevated in the two soils treated with chitosan. But for the planting soil, the content of available K was reduced. We concluded that chitosan improved soil available nutrient content, faciliated vegetable takeup of nutrients, and improved soil fertility and fertilizer efficiency8. Chitosan treatment can enhance vegetable resistance. Chitosan increased the content of praline in tomato leaves, and decreased the content of MDA and EL. Praline concent in cherry tomato was significantly increased with chitosan application. Chitosan also increased praline content in cabbage leaves, and decreased the MDA content, improving cold-resistance of Chinese cabbage.更多还原