棗(zizyphusjujubamill.)內生細菌研究

1、河北農業(yè)大學碩士學位論文棗(ZizyphusjujubaMill.)內生細菌研究姓名：李艷輝申請學位級別：碩士專業(yè)：果樹學指導教師：申連英；毛永民2009-06-10Study on Endophytic Bacteria of Chinese Jujube (Zizyphus jujuba Mill.) Author: Li Yan-hui Major: Pomology Supervisor: Shen Lian-ying Mao

2、Yong-min Abstract Endophytic bacteria are beneficial microbial resources for improving plant growth and abilities of antidisease and antiadversity. They extensively live in various kinds of plants. Our research investiga

3、ted the endophytic bacteria resources of different Chinese Jujube varieties. Their population dynamics and distribution within the plant cultivars and different plant organs were studied. The results revealed the diversi

4、ty and the occurrence of dominant species of endophytic bacteria. This is the basis for screening of plant growth promoting and plant pathogen antagonistic endophytic bacteria, and their application in sustainable agricu

5、lture. The major results are summarized as the following: One hundred and thirteen strains of endophytic bacteria were isolated from various organs of five varieties Chinese Jujube trees. The numbers of endophytic bacter

6、ia isolated from the plants were different according to the parts of the plants.The numbers of endophytic bacteria isolated from different varieties:Longzao(16.44×104CFU/g) > Dongzao (9.59×104CFU/g) > Jin

7、sixiaozao(5.00×104CFU/g) > Lizao(4.21×104CFU/g) > Gagazao (2.91×104CFU/g).The numbers of endophytic bacteria isolated from different organs:Bearing-shoot at current-year branch(16.91×104CFU/g) &

8、gt; Bearing-shoot at perennial branch (12.07×104CFU/g) > Perennial branch (7.58×104CFU/g) > Current-year branch (0.84×104CFU/g) > Leaves (0.73×104CFU/g). There are 45 strains of endophytes sh

9、owed antagonistic activities to the pathogen by dual-culture tests, in which strains 081 and 113 had the strongest inhibitory antagonistic effect through inhibitory activity test. Their antibiotic substances had inhibito

10、ry rates to the pathogens between 36.7%-61.7%. The antifungal compounds of two strains were stable to the heat treatment between 50℃and 90℃, and between pH5.0 and pH9.0. The rates of inhibition of 081 and 113 were the h

11、ighest at pH7.0 and pH8.0. However, the rates of inhibition of 081 declined when acidity and basicity are respectively strengthened. The rates of inhibition of 113 declined significantly when acidity are strengthened, bu

12、t hardly declined significantly when basicity are strengthened. The optimal culture pH values of 081 and 113 were 6.0 and 9.0, in the range of pH5.0-10.0. The optimal culture temperatures of two strains were 30℃ and 28℃,