摘要：在相同的条件下，测定食品级壳寡糖（编号 824）对西瓜枯萎病菌（Fusarium wilt），稻绿核病菌（Ustilaginoidea virens）,西瓜壳二孢（Ascochyta citrullina）,水稻纹枯病菌（Rhizoctorzia solani）的菌落直径和产孢量的影响。结果表明：西瓜枯萎病菌，稻绿核病,西瓜壳二孢,水稻纹枯病菌在含有不同浓度824号壳寡糖的PDA培养基上生长均受到不同程度的影响。对于西瓜枯萎病菌、稻绿核病菌和西瓜壳二孢而言，随着壳寡糖浓度的升高，三种病原真菌生长情况逐渐变差，在壳寡糖浓度为2 mg/mL的PDA培养基上菌种生长情况最差。表现为菌落直径最小，分生孢子产孢量最少。这表明，壳寡糖抑菌作用的发挥是浓度依赖性的。水稻纹枯病菌在不同浓度824号壳寡糖的PDA培养基中抑制作用不明显，这表明壳寡糖抑菌作用的发挥因菌种而异。本实验为进一步研究壳寡糖的抑菌作用提供了一定的实验依据。69058

毕业论文关键词：壳寡糖；植物病原真菌；菌落直径；产孢量

Inhibitory effect of a food grade oligochitosan on plant pathogenic fungi

Abstract: Under the same conditions, the inhibitory effect of a food grade oligochitosan (No. 824) on Fusarium wilt, Ustilaginoidea virens, Ascochyta citrullina and Rhizoctorzia solani were determined. The results showed that the growth of four plant pathogenic fungi on PDA medium with different concentrations of oligochitosan was affected at different degrees. For Fusarium wilt, Ustilaginoidea virens and Ascochyta citrullina, the growth of these three pathogenic fungi gradually became worse with the increase of the oligochitosan concentration and reached a maximum at 2 mg/mL. Compared to the control, the colony diameter and spore production quantity both reduced obviously in the oligochitosan-treated group. Results showed that the antifungal activity of the oligochitosan was concentration dependent. The inhibitory effect of oligochitosan on Rhizoctorzia solani was not obvious, which indicated that the antifungal activity of the oligochitosan were different according to the species of fungi. This experiment provided a certain experimental basis for further study of the antimicrobial effect of oligochitosan. 

Key words: oligochitosan; plant pathogenic fungi; diameter of the colony; spore production quantity

目  录

引言 1

1 材料与方法 2

1.1 实验材料 5

1.2 实验方法 5

2 结果与分析 8

2.1不同浓度壳寡糖对水稻纹枯病菌的菌落直径和产孢量的影响 8

2.2不同浓度壳寡糖对西瓜枯萎病菌的菌落直径和产孢量的影响 10

2.3不同浓度壳寡糖对稻绿核病菌的菌落直径和产孢量的影响 12

2.4不同浓度壳寡糖对西瓜壳二孢病菌的菌落直径和产孢量的影响 13

3 讨论 15

致    谢 16

参考文献 16

引言

     糖与人类生活的关系非常紧密，上世纪90年代初兴起的糖生物学是一门前沿的科学。糖生物工程是继基因工程，蛋白质工程后越来越吸引人目光的科技领域[1]。壳寡糖学名很多，比如壳聚寡糖，低聚壳寡糖，它是利用独创的生物技术加工而成的一种寡糖产品，分子量小，可溶于水，作用强大，优点比壳聚糖多，比壳聚糖易被人体吸收[2]，壳寡糖是目前为止自然界唯一带正电荷的糖[3]。