1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)

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Subject: search.filters.subject.Artocarpus heterophyllus

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    Microbial consortium against major fungal diseases of jackfruit (Attocarpus heterophyllus)
    (Department of Plant Pathology, College of Agriculture, Vellanikkara, 2025-01-30) Anjali, K; Shahida, K
    Jackfruit (Artocarpus heterophyllus Lam.) belonging to the family Moraceae is considered as a high value crop due to its multiple uses and is gaining popularity in large scale commercial agriculture. However, the rise of fungal and bacterial diseases poses a significant challenge to jackfruit cultivation, particularly in newly introduced, high yielding varieties that exhibit increased susceptibility compared to traditional types. The increased plant disease tolerance of indigenous jack varieties may be due to the influence of root exudates at the rhizosphere region that harbours a diverse community of microorganisms. Hence, this study was taken upto characterize the beneficial microbes from the rhizosphere soil of indigenous jack (Artocarpus heterophyllus), in vitro evaluation against major fungal pathogens of jackfruit; and preparation of microbial consortium. Diseased leaves, stem and fruits were collected from Thrissur and Ernakulam districts and fungal pathogens were isolated from these infected plant parts. Two fungal pathogens EK1 and TK2 with high disease severity and virulence were selected for this study and pathogenicity was proved by following Koch’s postulates. The isolate EK1 produced water soaked lesions on leaves and symptoms of stem rot with sporulating hyphae. Pure white, fluffy, rope like mycelia on the jackfruits with white and brown coloured sclerotia was observed in the case of isolate TK2. Cultural, morphological and molecular characterization of these isolates were done. Molecular characterization through sequencing of ITS region confirmed the identity of isolates as Phytophthora colocasiae and Agroathelia rolfsii. Purposive sampling survey was conducted in the three districts of Kerala, viz.,Thrissur (AEU 10), Palakkad (AEU 10 and 23), and Malappuram (AEU 11). The older jackfruit trees which are high yielding and healthy were selected for the collection of rhizosphere soil. Nine samples were obtained from nine locations of the three districts viz., Madakkathara, Panancherry, Kannara of Thrissur, Sankaramangalam, Pattenchery, Pattambi of Palakkad and Anakkayam, Kizhuparamba, Munduparamba of Malappuram districts. A total of 88 rhizosphere microbes were isolated, in which 37 isolates were fungi and 51 isolates were bacteria. In vitro screening was carried out to assess the antagonistic potential of these microbial isolates against P. colocasiae and A. rolfsii. One fungal and bacterial isolates showing highest inhibition were selected from each location. The fungal isolate MMF1 showed highest per cent inhibition against both the pathogens. It inhibited P. colocasiae by 76.30 per cent and A. rolfsii by 58.15 per cent. The bacterial isolate TMB4, was found to inhibit P. colocasiae by 100 per cent and A.rolfsii by 76.30 per cent. The selected nine fungal and bacterial isolates were subjected to cultural, morphological and biochemical characterization. The most promising fungal and bacterial isolates were identified as Trichoderma asperellum and Ochrobactrum sp. respectively by molecular characterization. Different biocontrol attributes of the selected fungal and bacterial isolates were evaluated. Hyperparasitism, production of siderophore, ammonia, antibiotics, volatile and non-volatile metabolites, HCN, enzymes like β-l,3-glucanase and cellulase production were studied and different isolates exhibited varying results. Compatibility studies were carried out among the selected fungal and bacterial isolates. Microbial consortia were prepared with compatible bacterial isolates, compatible fungal isolates and with both compatible fungal and bacterial isolates. The in vitro evaluation of the three microbial consortia against the pathogens were done along with KAU reference culture Pseudomonas fluorescens (PN 026), Trichoderma asperellum (KAU strain), and Plant Growth Promoting Microbes (PGPM). Treatment with compatible fungal isolates viz., PPF2, MAF1, MKF2 and MMF1 (T2) exerted a highest inhibition of 100 per cent against P. colocasiae and 84.40 per cent against A. rolfsii which was on par with T3 (consortium with compatible fungal and bacterial isolates) and T5 (Trichoderma asperellum KAU strain) in the case of P. colocasiae. The least inhibition of 68.89 per cent against P. colocasiae was recorded with PGPM (T6) followed by T1 (consortium with bacterial isolates). In the case of A. rolfsii, T1 exerted a least inhibition of 60.74 per cent followed by T6 with an inhibition of 73.33 per cent. Four fungal isolates in the best treatment (T2) were characterized at molecular level. MKF2 and MMF1 were identified as Trichoderma asperellum where as PPF2 and MAF1 were identified as Trichoderma harzianum. The future studies can be conducted at field level to evaluate the efficiency of the biocontrol agents at natural conditions. Their ability to improve plant health and disease resistance can also be validated to develop suitable formulations for the sustainable jackfruit cultivation.
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    Profiling bioactive compounds and nutrients in jackfruit (artocarpus heterophyllus Lam.) and developing a jackfruit based textured vegetable protein
    (Department of Community Science, College of Agriculture, Vellayani, 2018) Anila, H L; Suma Divakar
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    Development, packaging and storage of intermediate moisture jackfruit (Artocarpus heterophyllus L.)
    (Department of Processing Technology, College of Horticulture, Vellanikkara, 2016) Divya, S L; Saji Gomez
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    Screening of jack trees (Artocarpus heterophyllus Lam.) for quality timber production
    (Department of Forest Products and Utilization, College of Forestry, Vellanikkara, 2019) Jobin Kuriakose; Anoop, E V
    Artocarpus heterophyllus Lam, belonging to the family Moraceae and popularly known as jackfruit tree, is one of the important timber species commonly found in the homegardens of Kerala. The main objective of the present study was to identify plus trees of Artocarpus heterophyllus from Thrissur and Palakkad districts and to evaluate their seedling growth performance for quality timber production. Forty plus trees, twenty each of varikka and koozha variety were selected from both districts. Seedling biometric observations like stem height, collar diameter, leaf area, fresh weights and dry weights of stem, leaves and root showed significant differences throughout the study period, i e from 30 DAP (Days After Planting) to 150 DAP. At 150 DAP, seedling height ranged from 123.10 cm (FCV AH 22) to 68.35 cm (FCV AH 1) and collar diameter ranged from 14.39 mm (FCV AH 8) to 7.18 mm (FCV AH 7). At 150 DAP, FCV AH 4, FCV AH 22 and FCV AH 15 had the highest value for both fresh weight (33.88 g, 25.22 g and 25.25 g) and dry weight (16.41 g, 8.26 g and 8.54 g) of stem, leaf and root respectively. Other parameters like taproot length, number of leaves, Leaf Area Ratio, Specific Leaf Area, Absolute Growth Rate, Relative Growth Rate and Net Assimilation Rate were also found to be significant but not throughout the study period. The highest taproot length was noticed in FCV AH 2 (48.85 cm) and the least taproot length was in FCV AH 14 (30.45 cm) at 150 DAP. To establish a field trial plot, seedlings were out planted one year after nursery growth near the International Hostel at KAU, Vellanikkara. Field performance of the progenies were evaluated at 30 DAP. Seedling height and collar diameter were found to be significantly different among various seed sources. The average seedling height was 117.30 cm with values ranging from 143.94 cm to 96.35 cm and FCV AH 22 being the tallest. The mean collar diameter was 12.27 mm with FCV AH 29 having the highest (14.67 mm) value. Hierarchical cluster analysis based on the morphological and biometric characters was carried out and 40 plus tree sources were grouped into twenty-one clusters. Based on the biometric observations for 150 DAP and cluster analysis, it was found that Cluster 2 (FCV AH 2), Cluster 18 (FCV AH 8), Cluster 12 (FCV AH 9), Cluster 11 (FCV AH 15), Cluster 10 (FCV AH 21), Cluster 21 (FCV AH 22), and Cluster 15 (FCV AH 23) possess superior quality. Anatomical studies of young (six month old) Artocarpus heterophyllus seedlings from different seed sources and core samples of mature trees from a ‘Jack Gene Sanctuary’ of the Agricultural Research Station (ARS), KAU at Mannuthy revealed significant differences in various parameters. Vessel area, ray height, ray width, fibre length and fibre wall thickness were found to be significantly different in six month old seedlings, whereas samples from mature trees showed significant difference in vessel diameter, vessel area, vessel frequency, ray height and ray width. Mean vessel area increased from 4199.14 µm2 in young seedlings to 62569.05 µm2 in mature trees. Mean vessel diameter also increased from 126.43 µm in young seedlings to 276.58 µm in mature trees. Mean ray height and mean ray width were found to be 466.98 µm and 34.58 µm in young seedlings and 498.38 µm and 52.97 µm in mature trees respectively. Mean fibre length and fibre wall thickness were found to be 801.13 µm and 3.27 µm in young seedlings and 993.10 µm and 4.37 µm in mature trees Questionnaire survey conducted in Thrissur and Palakkad district had 46.34 per cent and 39 per cent positive response respectively towards growing jack tree as a timber species in homegardens. There is an increasing preference for dwarf varieties over tall indigenous varieties among the respondents in both districts. The increasing trend of planting dwarf varieties can have an adverse effect on the easy availability of good quality wood from our homesteads. Therefore, there is a pertinent need to protect the existing high quality tall varieties of jack trees.
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    Optimization of fertilizer regimes and understorey productivity in four-year-old Swietenia macrophylla King stands
    (Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2018) Vikas Kumar; Kunhamu, T K