2024_Characterization And Biological Control Of Corynespora Cassiicola, A Pathogen Of Leaf Spot Disease Of Carica Papaya
| Format: | General Document |
|---|
| _version_ | 1860798338286223360 |
|---|---|
| building | INTELEK Repository |
| collection | Online Access |
| collectionurl | https://intelek.unisza.edu.my/intelek/pages/search.php?search=!collection3 |
| copyright | Copyright©PWB2025 |
| country | Malaysia |
| date | 2024-10-28 |
| format | General Document |
| id | 17335 |
| institution | UniSZA |
| originalfilename | CHARACTERIZATION AND BIOLOGICAL CONTROL OF Corynespora cassiicola, A PATHOGEN OF LEAF SPOT DISEASE OF Carica papaya (PHD_2024).pdf |
| person | Mohammad Hailmi Sajili |
| recordtype | oai_dc |
| resourceurl | https://intelek.unisza.edu.my/intelek/pages/view.php?ref=17335 |
| sourcemedia | Server storage Scanned document |
| spelling | 17335 https://intelek.unisza.edu.my/intelek/pages/view.php?ref=17335 https://intelek.unisza.edu.my/intelek/pages/search.php?search=!collection3 General Document Malaysia Library Staff (Top Management) Library Staff (Management) Library Staff (Support) Terengganu Faculty of Bio-resources & Food Industry English application/pdf 1.7 Pseudomonas aeruginosa Server storage Scanned document Universiti Sultan Zainal Abidin UniSZA Private Access Universiti Sultan Zainal Abidin Plant Growth-Promoting Rhizobacteria Plant Growth-Promoting Rhizobacteria (PGPR) Pathogenicity Copyright©PWB2025 182 Dissertations, Academic 2024-10-28 Mohammad Hailmi Sajili Corynespora cassiicola Carica papaya Corynespora Leaf Spot Disease (CLSD) Biological control Rhizobacteria Koch’s postulate Environmental factor testing Appressorium formation Disease incidence Antagonistic bacteria Bacillus atrophaeus Bacillus cereus Corynespora cassiicola Carica papaya—Diseases and pests Fungal diseases of plants Plant pathogens—Identification Biological pest control—Rhizobacteria Agricultural biotechnology Plant-fungus interactions 2024_Characterization And Biological Control Of Corynespora Cassiicola, A Pathogen Of Leaf Spot Disease Of Carica Papaya Carica papaya, commonly known as ‘betik’, is a nutritious tropical fruit with a tremendous market. However, it was discovered that the re-emerge disease known as Corynespora Leaf Spot Disease (CLSD) causes devastating effects on the growth and yield of papaya crops. The disease still needs more in-depth study, especially concerning its biological control. Therefore, the objectives of this study are 1) to study the distribution, isolate, and identify the pathogen causing the CLSD of papaya, 2) to characterize the fungus C. cassiicola by environmental factor tests, 3) to investigate the pathogenicity mechanism of C. cassiicola on papaya leaves via microscopic observation, 4) to identify the potential rhizobacteria as biological control agents in controlling C. cassiicola and 5) to evaluate the potential of biocontrol agent bacteria as plant growth-promoting rhizobacteria (PGPR). The distribution of CLSD was studied by sampling from twelve papaya farms in Peninsular Malaysia. The isolated pathogenic fungi were identified using morphological and molecular methods, and Koch’s Postulate was carried out to confirm the causative agent of papaya leaf spot disease. Environmental factors that influenced the growth, spore germination, and production of C. cassiicola were tested using different media, temperatures, light density, and pH levels. Plant-pathogen interaction of C. cassiicola on C. papaya leaves was done using light microscopy and Scanning Electron Microscope (SEM). Antagonistic activities of bacteria were screened using dual culture, double plate and double layer agar tests. The potential bacteria with a percentage of growth inhibition (PIRG) value exceeding 80% were identified and selected for further study in controlling CLSD and PGPR. The distribution of the highest disease incidence rate (93%) was in the Northern Zone (PR2). Morphological and molecular identification confirmed the pathogenic fungi as C. cassiicola. Koch’s postulate showed that C. cassiicola was the causal agent for the leaf spot disease of papaya among isolated fungi. The optimum conditions for the growth, sporulation and germination of C. cassiicola were determined. SEM observation of appressorium formation confirmed that the mechanism of fungi pathogenicity was via direct penetration of the infected area. Three bacteria have been selected according to the best percentage inhibition of radial growth (PIRG) and identified as Pseudomonas aeruginosa (94.45%), Bacillus atrophaeus (89.95%) and B. cereus (88.51%). However, P. aeruginosa was more effective in controlling C. cassiicola in the field than B. cereus and B. atrophaeus. These bacteria also showed potential as PGPR by showing higher plant height, a more significant number of leaves, root weight and root length compared to controls. As conclusion, C. cassiicola was characterised and confirmed as the causal agent of leaf spot disease of papaya. P. aeruginosa, B. cereus and B. atrophaeus were identified as effective biological control agents and PGPR in controlling CLSD and promoting the growth of papaya crops. The findings help address the challenges faced in sustaining the economic value of this crop plant and support small growers in practising sustainable agriculture. uuid:74536a3f-1b3e-4c9d-a149-888f1b6338b0 CHARACTERIZATION AND BIOLOGICAL CONTROL OF Corynespora cassiicola, A PATHOGEN OF LEAF SPOT DISEASE OF Carica papaya (PHD_2024).pdf Thesis |
| spellingShingle | 2024_Characterization And Biological Control Of Corynespora Cassiicola, A Pathogen Of Leaf Spot Disease Of Carica Papaya |
| state | Terengganu |
| subject | Plant Growth-Promoting Rhizobacteria Dissertations, Academic Corynespora cassiicola Carica papaya—Diseases and pests Fungal diseases of plants Plant pathogens—Identification Biological pest control—Rhizobacteria Agricultural biotechnology Plant-fungus interactions |
| summary | Carica papaya, commonly known as ‘betik’, is a nutritious tropical fruit with a tremendous market. However, it was discovered that the re-emerge disease known as Corynespora Leaf Spot Disease (CLSD) causes devastating effects on the growth and yield of papaya crops. The disease still needs more in-depth study, especially concerning its biological control. Therefore, the objectives of this study are 1) to study the distribution, isolate, and identify the pathogen causing the CLSD of papaya, 2) to characterize the fungus C. cassiicola by environmental factor tests, 3) to investigate the pathogenicity mechanism of C. cassiicola on papaya leaves via microscopic observation, 4) to identify the potential rhizobacteria as biological control agents in controlling C. cassiicola and 5) to evaluate the potential of biocontrol agent bacteria as plant growth-promoting rhizobacteria (PGPR). The distribution of CLSD was studied by sampling from twelve papaya farms in Peninsular Malaysia. The isolated pathogenic fungi were identified using morphological and molecular methods, and Koch’s Postulate was carried out to confirm the causative agent of papaya leaf spot disease. Environmental factors that influenced the growth, spore germination, and production of C. cassiicola were tested using different media, temperatures, light density, and pH levels. Plant-pathogen interaction of C. cassiicola on C. papaya leaves was done using light microscopy and Scanning Electron Microscope (SEM). Antagonistic activities of bacteria were screened using dual culture, double plate and double layer agar tests. The potential bacteria with a percentage of growth inhibition (PIRG) value exceeding 80% were identified and selected for further study in controlling CLSD and PGPR. The distribution of the highest disease incidence rate (93%) was in the Northern Zone (PR2). Morphological and molecular identification confirmed the pathogenic fungi as C. cassiicola. Koch’s postulate showed that C. cassiicola was the causal agent for the leaf spot disease of papaya among isolated fungi. The optimum conditions for the growth, sporulation and germination of C. cassiicola were determined. SEM observation of appressorium formation confirmed that the mechanism of fungi pathogenicity was via direct penetration of the infected area. Three bacteria have been selected according to the best percentage inhibition of radial growth (PIRG) and identified as Pseudomonas aeruginosa (94.45%), Bacillus atrophaeus (89.95%) and B. cereus (88.51%). However, P. aeruginosa was more effective in controlling C. cassiicola in the field than B. cereus and B. atrophaeus. These bacteria also showed potential as PGPR by showing higher plant height, a more significant number of leaves, root weight and root length compared to controls. As conclusion, C. cassiicola was characterised and confirmed as the causal agent of leaf spot disease of papaya. P. aeruginosa, B. cereus and B. atrophaeus were identified as effective biological control agents and PGPR in controlling CLSD and promoting the growth of papaya crops. The findings help address the challenges faced in sustaining the economic value of this crop plant and support small growers in practising sustainable agriculture. |
| title | 2024_Characterization And Biological Control Of Corynespora Cassiicola, A Pathogen Of Leaf Spot Disease Of Carica Papaya |
| title_full | 2024_Characterization And Biological Control Of Corynespora Cassiicola, A Pathogen Of Leaf Spot Disease Of Carica Papaya |
| title_fullStr | 2024_Characterization And Biological Control Of Corynespora Cassiicola, A Pathogen Of Leaf Spot Disease Of Carica Papaya |
| title_full_unstemmed | 2024_Characterization And Biological Control Of Corynespora Cassiicola, A Pathogen Of Leaf Spot Disease Of Carica Papaya |
| title_short | 2024_Characterization And Biological Control Of Corynespora Cassiicola, A Pathogen Of Leaf Spot Disease Of Carica Papaya |
| title_sort | 2024_characterization and biological control of corynespora cassiicola, a pathogen of leaf spot disease of carica papaya |