Development of inoculant cultures of nitrogen fixing cyanobacteria from wetland ecosystem of Vellayani (Record no. 290250)
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| 000 -LEADER | |
|---|---|
| fixed length control field | 05008nam a22001577a 4500 |
| 082 ## - DEWEY DECIMAL CLASSIFICATION NUMBER | |
| Classification number | 660.62 |
| Item number | ARY/DE PG |
| 100 ## - MAIN ENTRY--PERSONAL NAME | |
| Personal name | Arya S |
| 245 ## - TITLE STATEMENT | |
| Title | Development of inoculant cultures of nitrogen fixing cyanobacteria from wetland ecosystem of Vellayani |
| 260 ## - PUBLICATION, DISTRIBUTION, ETC. (IMPRINT) | |
| Place of publication, distribution, etc | Vellayani |
| Name of publisher, distributor, etc | Department of Agricultural Microbiology, College of Agriculture |
| Date of publication, distribution, etc | 2022 |
| 300 ## - PHYSICAL DESCRIPTION | |
| Extent | 98p. |
| 502 ## - DISSERTATION NOTE | |
| Dissertation note | MSc |
| 520 ## - SUMMARY, ETC. | |
| Abstract | The study entitled “Development of inoculant cultures of nitrogen fixing cyanobacteria from wetland ecosystem of Vellayani” was conducted during the year 2019-2021 in the Department of Agricultural Microbiology, College of Agriculture, Vellayani, Thiruvananthapuram with the objective to isolate and characterize cyanobacterial strains with efficient nitrogen fixing capacity from wetland ecosystem of Vellayani and assess the plant growth promotion and biocontrol activity through in vitro screening process. Ten nitrogen fixing cyanobacteria were isolated from wetland ecosystem of Vellayani region and they were designated as VLY 1 - VLY 10. Tentative taxonomic identification of the isolates were done based on their morphological and biochemical characters. The isolates were tested for their pigment concentration like chlorophyll a, phycobiliproteins, carotenoids. The chlorophyll a concentration varied from 0.688 mg mL-1 to 5.372 mg mL-1. The phycocyanin, allophycocyanin and phycoerythrin concentrations ranged between 0.016 mg mL-1 to 0.036 mg mL-1,0.015 mg mL-1 to 0.037 mg mL-1 and 0.005 mg mL-1 to 0.017 mg mL-1 respectively. Maximum chlorophyll a and phycobiliproteins was recorded in Aphanocapsa sp.VLY 2. Carotenoid concentration ranged between 0.001 μg mL-1 to 0.006 μg mL-1 and the maximum was reported in Calothrixsp.VLY 10. The concentration of total proteins ranged between 102.57 μg mL-1 to 236.32 μg mL-1 and the maximum was reported in Oscillatoriasp.VLY 5. Antibiotic sensitivity profiling of the isolates was done against streptomycin (25 μg), tetracycline (10 μg), nalidixic acid (30 μg), penicillin (10 μg), erythromycin (15 μg), rifampicin (5 μg) and chloramphenicol (30 μg). The isolates like Aphanothecasp.VLY 1, Oscillatoriasp.VLY 5, Lyngbyasp.VLY 7, Chrococcussp.VLY 9 showed sensitivity against rifampicin with a sensitivity zone of 14mm, 10mm, 9mm, 11mm respectively. The isolate Aphanothecasp.VLY 1 showed sensitivity against streptomycin and tetracycline with a zone of 12mm and 8mm respectively. Oscillatoriasp.VLY 5 was sensitive against tetracycline with a zone of 13mm. The cyanobacterial isolates were tested for their plant growth promotion activity studies. Extracellular ammonia production ranged between 111.74 μmol mL-1 to 171 μmol mL-1 and maximum was reported by Chrococcussp.VLY 6. Nitrogen content of the isolates ranged between 0.200 mg mL-1to 0.280 mg mL-1 and the isolate Oscillatoriasp.VLY 5 reported the maximum nitrogen content. The Indole Acetic Acid production ranged between 1.47 μg mL-1 to 7.10 μg mL-1. Maximum IAA production was recorded in Chrococcussp.VLY 6. The antagonistic activity of the isolates against plant pathogenic bacteria (Xanthomonas oryzae) and fungi (Pythium ultimum, Phytophthora capsici, Fusarium oxysporumf.sp. solani, Rhizoctonia solani) was investigated using disc diffusion method. The isolate Aphanothecasp.VLY 1 and Microcystissp.VLY 3 showed antagonistic activity against Xanthomonas oryzaewith an inhibition zone of 7.12 mm amd 8.20 mm respectively. The cyanobacterial isolates were screened based on weighted average ranking and Chrococcussp.VLY 6 was selected and evaluated for growth promotion under in vitro condition in rice. The rice seeds were subjected to thirteen treatments such as T1 – 10 mL sterile distilled water, T2 – 10 mL sterile BG-11 medium(without tryptophan). T3 – 10 mL sterile BG-11 medium amended with 5 mg mL-1 tryptophan, T4 to T8– 10mL sterile distilled water mixed with 20 μL, 40 μL, 60 μL, 80 μL, 100 μL of cyanobacterial extract (culture medium amended without tryptophan), T9 to T13 – 10 mL sterile distilled water mixed with 20 μL, 40 μL, 60 μL, 80 μL, 100 μL of cyanobacterial extract (culture medium amended with 5 mg mL-1 tryptophan). Maximum germination percentage was observed in seeds treated with 10 mL sterile distilled water and 40 µL cyanobacterial culture in BG 11 amended with 5mgmL-1of tryptophan.Also this treatment recorded the maximum shoot length (6.83 cm), root length (12.23 cm), shoot dry weight (4.62 mg), root dry weight (2.91 mg), seedling vigour index (1781) and shoot root ratio (2.7). Based on the results of present study, Oscillatoriasp.VLY 5 and Chrococcussp.VLY 6 are the superior isolates for plant growth promotion. Also, Microcystissp.VLY 3 is the best among the isolates which showed antibacterial activity. |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name as entry element | Agricultural Microbiology |
| 700 ## - ADDED ENTRY--PERSONAL NAME | |
| Personal name | Chitra N (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 |
|---|---|---|---|---|---|---|---|---|---|
| Not For Loan | Reference Book | KAU Central Library, Thrissur | KAU Central Library, Thrissur | Theses | 2023-05-03 | 660.62 ARY/DE PG | 175622 | 2023-05-03 | Theses |