Endophytic bacteria for plant growth promotion and management of web blight of cowpea (Record no. 289358)
[ view plain ]
| 000 -LEADER | |
|---|---|
| fixed length control field | 05144nam a22001817a 4500 |
| 082 ## - DEWEY DECIMAL CLASSIFICATION NUMBER | |
| Classification number | 632.3 |
| Item number | SIV/EN PG |
| 100 ## - MAIN ENTRY--PERSONAL NAME | |
| Personal name | Siva, M |
| 245 ## - TITLE STATEMENT | |
| Title | Endophytic bacteria for plant growth promotion and management of web blight of cowpea |
| 260 ## - PUBLICATION, DISTRIBUTION, ETC. (IMPRINT) | |
| Place of publication, distribution, etc | Vellayani |
| Name of publisher, distributor, etc | Department of Plant Pathology, College of Agriculture |
| Date of publication, distribution, etc | 2021 |
| 300 ## - PHYSICAL DESCRIPTION | |
| Extent | 127p. |
| 502 ## - DISSERTATION NOTE | |
| Dissertation note | M Sc |
| 520 ## - SUMMARY, ETC. | |
| Abstract | The study entitled “Endophytic bacteria for plant growth promotion and management of web blight of cowpea” was conducted in Department of Plant Pathology, College of Agriculture, Vellayani during 2019-2021 with the objective to evaluate endophytic bacteria inplant growth promotion and management of web blight of cowpea. Endophytic bacteria were isolated from healthy root, stem and leaves of fodder cowpea var. Aiswarya (22 isolates) and bush cowpea var. Bhagyalakshmi (16 isolates) from Instructional farm, COA Vellayani and farmer’s field at Naruvamoodu respectively. The isolates were purified and maintained for further studies. The pathogen Rhizoctonia solani causing web blight of cowpea was isolated from infected plant samples and pathogenicity tests were carried out. The isolates of endophytic bacteria were screened against R.solani by testing their antagonistic properties adopting dual culture technique. The results revealed that isolate CBRE5 (9.33 mm) showed maximum zone of inhibition against R. solani which was on par with CBRE1 (8.83 mm) followed by CBSE5 (8.33 mm). The mycelial growth inhibition of R. solani was recorded maximum (48.52 %) by the isolate CBRE5 followed by CBRE1 (42.22 %) which was on par with CBSE5 (41.85 %). The culture filtrate obtained from the isolates CFLE3 and CBRE5 recorded maximum zone of inhibition against R. solani. Based on the results of direct and indirect antagonism of endophytic bacteria, 20 isolates were selected as promising ones for biopriming of cowpea seeds. Surface sterilized cowpea seeds were bio-primed with selected bacterial endophytes at 108 cfu/ ml using roll towel assay. The cowpea seedlings treated with isolate CFLE3 recorded the maximum seedling vigour index – I and II (4087.33 and 7.66 respectively) which was on par with CBRE5 (3598.00 and 6.73 respectively) followed by CBSE5 (3452.33 and 6.70 respectively). Based on the results of roll towel assay the isolates CFLE3, CBRE5 and CBSE5 were selected as the best three bacterial endophytes for further studies. The promising endophytic bacterial isolates were tentatively identified as Bacillus through morphological, cultural and biochemical characters. The identities of the species of these isolates were further confirmed through 16S rRNA analyses as Bacillus subtilis(CFLE3), B. amyloliquefaciens (CBRE5) and B. velezensis (CBSE5). The compatibility studiesamong the best three bacterial endophytes following disc diffusion method and cross streak plate assay indicated that the isolates were compatible among themselves. In pot culture experiment, seed biopriming for 4 h along with foliar application (20 and 40 DAS) of B. velezensis CBRE5recorded minimum percent disease index (PDI) (32.33) on 14 DAI which was on par with the treatment with B. amyloliquefaciens CBSE5 (PDI- 39.33) followed by treatment combination with B. amyloliquefaciens CBSE5 and B. velezensis CBRE5 (PDI – 41.33). In vivo evaluation of best three endophytic bacterial isolates and their combinations for plant growth promotion indicated that combined seed biopriming for 4 h along with foliar application of B. amyloliquefaciens CBSE5 and B. velezensis CBRE5 (20 and 40 DAS) recorded maximum values for all growth parameters viz. shoot length (47.40 cm), root length (40.93 cm), shoot fresh weight (139.16 g), root fresh weight (49.33 g), shoot dry weight (27.83 g), root dry weight (6.33 g), pod yield (236.66 g) and number of pods per plant (36). However, the plants treated with isolate B. amyloliquefaciens CBSE5 exhibited early flowering (33 DAS). The best three endophytic bacterial isolates were evaluated for their plant growth promoting traits such as production of indole acetic acid (IAA), ammonia, phosphate, siderophore and HCN. B. amyloliquefaciens CBSE5 recorded highest IAA (3.54 μg/ml) and siderophore (zone of colouration – 6 mm) production. Whereas, the isolate B. velezensis CBRE5 showed highest ammonia (177.29 μmol/ml) and phosphate (zone solubilization - 2mm) production. Thus, the present study indicated that seed biopriming for 4 h along with foliar application (20 and 40 DAS) of B. velezensis CBRE5 was most effective treatment for the management of web blight of cowpea whereas combined seed biopriming for 4 h along with foliar application (20 and 40 DAS) of B. amyloliquefaciens CBSE5 and B. velezensis CBRE5 was the best treatment in plant growth promotion in vivo which could be further validated under field conditions for ecofriendly and sustainable safe – to – eat crop production. |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name as entry element | Plant Pathology |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name as entry element | Endophytic bacteria |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name as entry element | Cowpea |
| 700 ## - ADDED ENTRY--PERSONAL NAME | |
| Personal name | Sreeja, S J (Guide) |
| 942 ## - ADDED ENTRY ELEMENTS (KOHA) | |
| Source of classification or shelving scheme | |
| Item type | Theses |
| Not for loan | Collection code | Permanent location | Current location | Shelving location | Date acquired | Full call number | Barcode | Date last seen | Koha item type |
|---|---|---|---|---|---|---|---|---|---|
| Reference Book | KAU Central Library, Thrissur | KAU Central Library, Thrissur | Theses | 2022-04-22 | 632.3 SIV/EN PG | 175298 | 2022-04-22 | Theses |