APPLICATION OF FUNGICIDES AND PLANT EXTRACTS IN CONTROL OF FUSARIUM ROT OF TOMATO FRUITS

In the present study few Fungicides and Plant extracts were tested for the control of Fusarium rot of tomato fruits, among fungicides Carbendazim was found to be the most effective in inhibiting the mycelia growth of Fusarium solani. In the case of leaf extracts, the leaf extracts of Neem (Azadirachta indica) reduced effectively the incidence of Fusarium rot of tomato fruits.

Interactive effect of biocontrol agents in the management of Fusarium rot in cardamom and its impact on plant defense mechanism

Cardamom plantations are subjected to constant threat due to the Fusarium rot disease caused by Fusarium oxysporum Schlecht which is pronounced during summer months. The current study deals with the identification of an effective and ecofriendly management practice for the disease through the use of biocontrol agents. Survey conducted between February and May 2019 revealed maximum disease severity and incidence in Pampadumpara panchayat of Nedumkandam block (84.40% and 100%) and minimum in Erattaar panchayat of Kattappanablock (50.40% and 60.00%). A pot culture experiment was conducted to study the effect of three bioagents (Glomus fasciculatum, Trichoderma asperellum and Pseudomonas fluorescens) individually as well as in combinations. Root inoculation of G. fasciculatum with basal application and spray with P. fluorescens as well as root inoculation of G. fasciculatum along with basal application of T. asperellum and P. fluorescens spray were identifiedto be effective against the disease. Disease suppression by the above bioagents was facilitated by reduced pathogen antagonist ratio in the soil, high level of mycorrhizal colonization in the roots and enhanced biochemical activity of defense enzymes like peroxidase, poly phenol oxidase and phenylalanine ammonia lyase in the plants.

Pathogenesis-Related Genes of PR1, PR2, PR4 and PR5 Families Are Involved in the Response to Fusarium Infection in Garlic (Allium sativum L.)

Plants of the genus Allium developed a diversity of defense mechanisms against pathogenic fungi of the genus Fusarium, including transcriptional activation of pathogenesis-related (PR) genes. However, the information on the regulation of PR factors in garlic (Allium sativum L.) is limited. In the present study, we identified AsPR genes putatively encoding PR1, PR2, PR4, and PR5 proteins in A. sativum cv. Ershuizao, which may be involved in the defense against Fusarium infection. The promoters of the AsPR1–5 genes contained jasmonic acid-, salicylic acid-, gibberellin-, abscisic acid-, auxin-, ethylene-, and stress-responsive elements associated with the response to plant parasites. The expression of AsPR1c, d, g, k, AsPR2b, AsPR5a, c (in roots), and AsPR4a(c), b, and AsPR2c (in stems and cloves) significantly differed between garlic cultivars resistant and susceptible to Fusarium rot, suggesting that it could define the PR protein-mediated protection against Fusarium infection in garlic. Our results provide insights into the role of PR factors in A. sativum and may be useful for breeding programs to increase the resistance of Allium crops to Fusarium infections.

First report of post-harvest Fusarium rot of mandarin Citrus reticulata cv. ‘Kinnow’ caused by Fusarium equiseti in Pakistan

Citrus reticulata cv. ‘Kinnow’ mandarin is the most popular and widely grown fruit crop in Pakistan. During 2017, a survey was conducted to the local citrus fruit markets of Faisalabad, Pakistan. Citrus fruits (n=50) exhibiting stem end rot and fruit rot were collected with 15% disease incidence. The stem end region showed light to dark brown lesions and white fungal growth was also observed in the severely infected fruit. Infected fruit were excised into 2mm2 segments, surface disinfected with 1% NaClO, rinsed with sterilized water and dried. Later, these tissues were placed on potato dextrose agar (PDA) medium and subsequently incubated at 25 °C. Purified isolates produced white colonies with beige pigmentation. The frequency of fungal isolation was 47%. Microscopic observations revealed that macroconidia (n=50) had 5 to 6 septations, with a prominent dorsiventral curvature, tapered and elongated apical cell, and a foot shape basal cell. The macroconidia were measuring 22 to 45 × 2.9 to 4.3 µm with an average of 31 × 3.6 µm. However, microconidia were not observed. Chlamydospores were globose, intercalary, solitary, or in pairs, appearing in chains (Leslie and Summerell 2006). For molecular identification, DNA was extracted from all isolates. The internal transcribed spacer region (ITS) ITS1/4 (White et al. 1990), translation elongation factor-1 alpha (TEF) EF1/2 (O’Donnell et al. 1998), and RNA polymerase II subunit 1 (RPB1) (O'Donnell et al. 2013) were amplified using PCR and the product was subsequently sequenced. Based on BLAST analysis, the isolate was identified as Fusarium equiseti (FUS-21). The sequences of the representative isolate FUS-21 were deposited in the GenBank with accession numbers (ITS, MH581300), (TEF, MK203749), and (RPB1, MW596599) showing more than 99% similarity with ITS accession GQ505683, TEF accession GQ505594, and 100% to RPB1 accession JX171481. To determine the pathogenicity, 40 healthy surface disinfested citrus fruit were taken. The fruit were inoculated by creating artificial wounds on the surface with a sterilized needle and 10 μL of 105 spores/mL was deposited in the wounds. In case of control fruit were inoculated with 10 μL sterilized distilled water only, and incubated at 25 °C. All fruit inoculated with the putative pathogen, developed symptoms like the original fruit from which they were isolated. The pathogenicity test was repeated twice. Visible white mycelium appeared at the stem end region and the fruits became dried as the infection progressed. However, the control fruit remained asymptomatic. The pathogen was re-isolated from infected fruit and identified based on morphometric and molecular analysis. Previously we have reported F. oxysporum causing citrus fruit rot in Pakistan (Moosa et al. 2020). This is the first report of F. equiseti causing post-harvest rot of citrus fruits in Pakistan. Kinnow is an important fruit crop of Pakistan with huge export value the management of Fusarium rot is quite important to save the loss of fresh produce.

A Study of Fungal Diseases Occurring on Stored Tomatoes of Balkhu Agriculture and Vegetable Market, Nepal

Tomatoes are one of the most widely produced and consumed vegetable in Nepal. Fungal pathogens deteriorate the quality and quantity of tomato and cause health hazards to the consumers as well as economic loss to the traders. This study was carried out to identify some fungal diseases associated with post-harvest deterioration of stored tomato fruits in Balkhu Agriculture and vegetable Market of Kathmandu, Nepal. Collected samples were cultured in Potato Dextrose Agar (PDA) media in complete randomized design. Fifteen species of fungi namely Alternaria alternata, A. solani, Aspergillus niger, Botrytis cinerea, Fulvum fulva, Colletotrichum truncatum, Curvularia spicifera, Fusarium oxysporum, Dipodascus geotrichum, Mucor mucedo, Penicillium chrysogenum, Phytophthora infestans, Boeremia exigua, Pythium aphanidermatum and Rhizopus stolonifer were identified. These were responsible for 14 different diseases of Alternaria fruit rot, Anthracnose, Black mold rot, Botrytis Bunch Rot, Damping off/ fruit rot, Drechslera mold, Fusarium rot, Mucor rot, Penicillum rot, Boeremia blight, Phytophthora rot, Rhizopus rot, Russet, and, Sour rot. The presence of these fungi and corresponding rot diseases on stored tomato indicates the need for management of fungi, farm sanitation and improved market in order to prevent field-to-storage transmission of pathogen.

Study on the adsorption effect of diatomite on neosolaniol (NEO) in muskmelon fruits inoculated with Fusarium sulphureum

Fusarium rot of muskmelon fruit is a common postharvest disease, which not only causes quantity deterioration but also leads to trichothecene accumulation in decay fruits. Neosolaniol (NEO) is one of main trichothecene, which poses a severe threat to human health. In this study, UPLC-MS/MS method was developed to determine NEO in muskmelon inoculated with Fusarium sulphureum. Diatomite was used to remove NEO in muskmelon and the adsorption kinetics, adsorption thermodynamics were analyzed in this adsorption process, and the changes of muskmelon juice quality before and after adsorption were investigated. The results showed that diatomite was a good adsorbent to remove NEO from muskmelon juice. The reaction process fits the Langmuir model and it was spontaneous exothermic reaction and not easy to be desorbed; the kinetic results showed that the maximum adsorption capacity was 12.35 μg/g, and this process fits the Pseudo-second-order model; diatomite had no significant effect on juice quality.

ANTIFUNGAL ACTIVITY OF TRICHODERMA VIRIDAE, CALOTROPIS GIGANTEA EXTRACT AGAINST FUNGAL PATHOGENS OF JUTE PLANT.

Jute is infected by more than 12 types of phytopathogenic fungi. Charcoal rot, anthracnose and Fusarium rot are major jute diseases of eastern Nepal. Hence, the objective of this study was to control three fungal pathogens viz; Macrophominia phaseolinia, Fusarium solani and Colletotrichum species using Trichoderma viridae and Calotropis gigantea extract. All fungal pathogens were isolated from jute field. Occurrence of each disease was checked. Calotropis gigantea extract as well as Trichoderma showed good antifungal activity. In this study, 7% methanolic extract solution of Calotropis showed 43.6% inhibition of Colletotrichum, 38.91% inhibition on Fusarium solani and 37.81% inhibition on Macrophominia phaseolinia. Similarly, Trichoderma viridae inhibited the Fusarium solani growth by 51.33%, Macrophominia phaseolinia growth by 39.50% and Colletotrichum growth by 36.12%. The antifungal activity of Calotropis extract against test and control was statistically significant (p<0.001). It is concluded that biological control agents like Trichoderma viridae, Calotropis gigantea can effectively reduce the fungal phytopathogens of jute and can be used as good alternatives to fungicides in farming

Biological Features of Gladiolus hybridus in Connection with the Adaptation of the Siberian Region

The adaptive possibilities of the varietal diversity of Gladiolus hybridus in the forest-steppe zone of Western Siberia are analyzed. Morphobiological features of shoot formation are shown. Long-term (1999–2019) results of seasonal development of plants in generative age state are presented. The specificity of the terms of flowering varies from different groups of the sum of positive temperatures. Flowering in Novosibirsk occurs in early varieties with the sum of positive temperatures >1462° C, medium >1558° C, late >1711° C. It was determined that in the prewinter the cone of growth of the shoot of renewal forms rudimentary vegetative organs, which corresponds to the second stage of organogenesis. Differentiation of the cone of growth of escape to generative organs begins during the period of intensive growth of escape in June. During the period from 60–73 days, the cone of growth of the shoot passes intrarenal development from III to VIII stages of organogenesis. IX–XII stages of organogenesis correspond to the phenological stages from flowering to fruiting. Flowering duration is 10–25 days, seasonal development 118–123 days. There was a decrease in the coefficient of vegetative reproduction in varieties from 2015 to 2018 of 2–12 times. The main ecological niche of the pathogen Fusarium rot of gladiolus (of vosb. Fusarium oxysporum f. gladioli) are underground organs (roots, corms), and also-above-ground organs of plants. Comparison of the degree of resistance of gladiolus to Fusarium showed a different reaction of varieties during the growing season and storage of corms.