Management of water stress in tomato (Solanum lycopersicum L.) through beneficial root endophytic fungus, piriformospora indica (Record no. 291130)
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| 000 -LEADER | |
|---|---|
| fixed length control field | 08186nam a22002177a 4500 |
| 082 ## - DEWEY DECIMAL CLASSIFICATION NUMBER | |
| Classification number | 635.6 |
| Item number | ARU/MA PhD |
| 100 ## - MAIN ENTRY--PERSONAL NAME | |
| Personal name | Aruna, S |
| 245 ## - TITLE STATEMENT | |
| Title | Management of water stress in tomato (Solanum lycopersicum L.) through beneficial root endophytic fungus, piriformospora indica |
| 260 ## - PUBLICATION, DISTRIBUTION, ETC. (IMPRINT) | |
| Place of publication, distribution, etc | Vellayani |
| Name of publisher, distributor, etc | Department of vegetable science, college of agriculture |
| Date of publication, distribution, etc | 2023 |
| 300 ## - PHYSICAL DESCRIPTION | |
| Extent | 206p. |
| 502 ## - DISSERTATION NOTE | |
| Dissertation note | PhD |
| 520 3# - SUMMARY, ETC. | |
| Abstract | Management of water stress in tomato (Solanum lycopersicum L.) through beneficial root endophytic fungus, Piriformospora indica The study entitled ‘Management of water stress in tomato (Solanum lycopersicum L.) through beneficial root endophytic fungus, Piriformospora indica’ was conducted at College of Agriculture, Vellayani during 2019- 2022 with the objective to to enhance water stress tolerance in tomato plants through colonization with the beneficial root-endophytic fungus, Piriformospora indica, and to explore the underlying physiological and molecular mechanisms driving this tolerance. The comprehensive study comprised five distinct experiments wherein P. indica-colonized and non-colonized tomato plants of the variety Vellayani Vijai were meticulously evaluated under varying water stress conditions. The cocultivation of tomato seedlings with the fungus was carried out according to the established standard protocol (Johnson et al., 2011). Following the co-cultivation phase, both colonized and non-colonized tomato seedlings were transplanted into pots under protected conditions at 30 days after sowing (DAS). Subsequently, water stress was induced by adapting different methods to simulate water stress (limiting irrigation, applying polyethylene glycol (PEG), mannitol, abscisic acid (ABA) and flooding) at 45 DAS, persisting for a duration of seven days. In all the experiments, the results consistently demonstrated the positive impact of P. indica colonization on various vegetative traits, such as plant height, stem girth, primary branches per plant, leaf length, leaf width, and leaf area. Conversely, with the escalation of water stress levels, these vital vegetative characteristics exhibited noticeable declines. Moreover, P. indica colonized tomato plants consistently exhibited significant advancements in achieving first and fifty percent flowering compared to their non-colonized counterparts. This consistent 226 trend held true across diverse water stress conditions, whether induced by restricted irrigation, the application of PEG, mannitol, ABA, or even submergence. The impact of P. indica colonization was evident in various aspects of flowering and fruiting. The number of flower clusters per plant, flowers per cluster, fruit set percentage, fruits per truss, and fruits per plant were all significantly enhanced. P. indica colonization consistently resulted in approximately 6-14% higher fruit set. Additionally, colonized plants showed an impressive increase up to 36% in the number of fruits formed per cluster. For instance, under mannitolinduced stress, colonized plants demonstrated a remarkable 58% increase in the number of fruits per plant. Colonized plants consistently yielded larger tomatoes, as evidenced by their greater fruit length and diameter, even across varying stress levels, when compared to non-colonized plants. The fruit weight in colonized plants consistently exceeded that of non-colonized plants in all experiments, with a pronounced 16-28% enhancement. Colonized plants demonstrated significantly higher yields, producing up to double the yield obtained from non-colonized plants (401.11g vs. 280.03g as observed in first experiment). Similarly, in experiments involving the application of PEG, mannitol, ABA, and submergence, colonized plants consistently achieved superior yields. As the stress levels increased the effect of P. indica became more evident. For instance, when comparing the yield of plants that were colonized with those that were not, there was a noticeable enhancement in yield by 14%, 28%, 146%, and 376% under the conditions of normal irrigation, 75% field capacity (FC), 50% FC, and 25% FC, respectively. Across all experiments, the qualitative attributes of tomato fruits, including ascorbic acid, lycopene, and TSS, displayed an upward trend with rising stress levels. Importantly, P. indica colonization consistently led to improved fruit quality, manifesting as higher levels of ascorbic acid, lycopene, and TSS in all experiments, regardless of whether the plants were subjected to stress or not. In all experiments, physiological parameters such as relative water content (RWC), cell membrane stability (CMS), and chlorophyll stability index (CSI) 227 exhibited a notable decline as water stress levels increased, with reductions of up to 50% observed in RWC under severe stress conditions. However, the presence of P. indica colonization consistently mitigated this decline, enhancing RWC by 6- 12%, CMS by 13-27% and CSI by 16-35% compared to non-colonized plants under severe stress conditions in all conducted experiments. Tomato plants colonized by P. indica exhibited significantly elevated proline accumulation when compared to the control plants under conditions of water stress. During instances of moderate stress, characterized by 50% field capacity (FC), -7 bar PEG, 7% mannitol, and 6µmol ABA, proline accumulation in the colonized tomato plants was notably enhanced by a range of 41-69%. Furthermore, when subjected to more severe stress conditions, such as 25% FC, -10 bar PEG, 10% mannitol, and 10µmol ABA, the proline accumulation witnessed an even more substantial increase, ranging from 55 to 116%. The colonization of P. indica consistently amplified anti-oxidant activities (superoxide dismutase, catalase and peroxidase) in response to escalating water stress levels. As the intensity of stress heightened, in all the conducted experiments, the colonized plants consistently exhibited significantly higher anti-oxidant activities in comparison to the non-colonized plants subjected to equivalent levels of water stress. The increased anti-oxidant activities in P. indica-colonized plants suggests an enhanced ability to scavenge superoxide radicals and protect against oxidative stress caused by drought. P. indica colonization in tomato plants significantly enhanced the expression of the stress responsive transcription factor-SlAREB1, particularly under drought stress conditions. When both colonized and non-colonized tomato plants were subjected to drought stress (50% FC), non-colonized plants exhibited only 1.75-fold increase in gene expression compared to the control (normally irrigated), whereas P. indica-colonized plants displayed a significantly higher 2.76-fold increase. This highlights the potential synergy between P. indica colonization and gene expression in response to drought stress. 228 In conclusion, colonization with P. indica had a consistently positive impact on multiple facets of tomato plant growth and development, even under varying water stress conditions. Across all experimental conditions, the colonized tomato plants consistently outperformed their non-colonized counterparts, highlighting the potential of P. indica as a valuable ally in sustainable agriculture, particularly in mitigating the adverse effects of water stress on tomato crops. This symbiotic relationship provides a promising avenue for optimizing water usage in tomato cultivation. Further studies should be conducted to elucidate the role of other antioxidants, and molecular mechanisms involved in this host-endophyte interactions. Field and multi-locational studies should also be conducted for confirmation of the results 228 |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name as entry element | vegetable science |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name as entry element | Solanum lycopersicum L. |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name as entry element | Arbuscular mycorrhizal fungi |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name as entry element | Nitro blue tetrazolium |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name as entry element | water stress in tomato |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name as entry element | Reactive oxygen species |
| 700 ## - ADDED ENTRY--PERSONAL NAME | |
| Personal name | Rafeekher, M (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 | Thesis | KAU Central Library, Thrissur | KAU Central Library, Thrissur | Theses | 2024-04-02 | 635.6 ARU/MA PhD | 175978 | 2024-04-02 | Theses |