Fusarium Udum Research Articles

New insights into synergistic interactions of root-knot nematode and wilt causing fungi on pigeon pea in sandy loam soil

AbstractA study under pot conditions was undertaken to know the relationship between plant biomass and inoculum densities of Meloidogyne incognita. Similarly, plant biomass—Fusarium udum relationship was also observed. Results revealed that increased inoculum densities resulted in corresponding decrease in plant biomass markers. Compared to control plants, 2000 nematode inoculation caused significant damage in phytobiomass (23.07–26.32%) of pigeon pea. 2.0 g F. udum inoculation caused significant impairment in different plant growth characteristics (22.96–26.02%) over control plants at P < 0.05. The interactive study revealed that concomitant, M. incognita + F. udum inoculation caused the maximum reduction (33.68–56.66%) in plant biomass. Next to this, M. incognita inoculation 15 days prior to F. udum and F. udum inoculation 15 days prior to M. incognita caused an impairment of (28.55–50.11%) and (23.99–43.33%), respectively. However, they were statistically either at par or non-significant over each other. Disease assay revealed that M. incognita multiplication rate was correspondingly augmented upon the rise of nematode concentration, conversely, the reproduction factor was progressively decreased. Pathogens interactive facet revealed that M. incognita inoculated plants showed a higher root galls (99.40), eggs (79.20), fecundity (199.80), and nematode population (13,785.60). The presence of F. udum suppressed nematode multiplication ability. However, concomitant inoculation of M. incognita and F. udum aggravated percent wilt severity (65.48%) thus exhibiting a synergistic interaction between the vascular pathogens.

Seasonal variation and diversity of endophytic fungi isolated from different parts of Andrographis paniculata (Burm. f.) Wall. ex Nees

A total of 18 species of endophytic fungi were isolated from Andrographis paniculata plant. The fungi were: Aspergillus flavus, A. niger, A. terreus, Cladosporium sp., Colletotrichum sp., Curvularia chonburiensis, Curvularia lycopersici, Fusarium solani, Fusarium udum, Fusarium sp. 1, Lasiodiplodia theobromae, Monodictys paradoxa, P. chrysogenum, P. oxalicum, Penicillium sp. 1, Penicillium sp. 2, Penicillium sp. 3, and Scytalidium lignicola. In summer, 18 species of fungi were isolated from A. paniculata while 13 fungal species were isolated in winter season. The highest value of Shannon and Simpson diversity index was found in the leaf in summer season and the lowest value in the stem in winter season. Maximum species richness of endophytic fungi was recorded in leaf in Margalef‘s index and Menhinick index in winter season. Minimum species richness of endophytic fungi was recorded in stem in Margalef’s index and Menhinick index in summer season. Biodivers. Conserv. Bioresour. Manag. 2024, 10(1): 29-34

Harnessing the power of native biocontrol agents against wilt disease of Pigeonpea incited by Fusarium udum

Fusarium wilt, caused by (Fusarium udum Butler), is a significant threat to pigeonpea crops worldwide, leading to substantial yield losses. Traditional approaches like fungicides and resistant cultivars are not practical due to the persistent and evolving nature of the pathogen. Therefore, native biocontrol agents are considered to be more sustainable solution, as they adapt well to local soil and climatic conditions. In this study, five isolates of F. udum infecting pigeonpea were isolated from various cultivars and characterized morphologically and molecularly. The isolate from the ICP 8858 cultivar displayed the highest virulence of 90%. Besides, 100 endophytic bacteria, 100 rhizosphere bacteria and three Trichoderma spp. were isolated and tested against F. udum isolated from ICP 8858 under in vitro conditions. Out of the 200 bacteria tested, nine showed highest inhibition, including Rb-4 (Bacillus sp.), Rb-11 (B. subtilis), Rb-14 (B. megaterium), Rb-18 (B. subtilis), Rb-19 (B. velezensis), Eb-8 (Bacillus sp.), Eb-11 (B. subtilis), Eb-13 (P. aeruginosa), and Eb-21 (P. aeruginosa). Similarly, Trichoderma spp. were identified as T. harzianum, T. asperellum and Trichoderma sp. Notably, Rb-18 (B. subtilis) and Eb-21 (P. aeruginosa) exhibited promising characteristics such as the production of hydrogen cyanide (HCN), cellulase, siderophores, ammonia and nutrient solubilization. Furthermore, treating pigeonpea seedlings with these beneficial microorganisms led to increased levels of key enzymes (POD, PPO, and PAL) associated with resistance to Fusarium wilt, compared to untreated controls. In field trials conducted for four seasons, the application of these potential biocontrol agents as seed treatments on the susceptible ICP2376 cultivar led to the lowest disease incidence. Specifically, treatments T2 (33.33) (P. aeruginosa) and T3 (35.41) (T. harzianium) exhibited the lowest disease incidence, followed by T6 (36.5) (Carbendizim), T1 (36.66) (B. subtilis), T4 (52.91) (T. asperellum) and T5 (53.33) (Trichoderma sp.). Results of this study revealed that, P. aeruginosa (Eb-21), B. subtilis (Rb-18) and T. harzianum can be used for plant growth promotion and management of Fusarium wilt of pigeonpea.

Pyrolytic oil from Muli bamboo (Melocanna baccifera, Roxb.): Biological potential and possible functional attributes

Bamboos with over 160 different species are important sources of food and other value-added products especially among the tribal communities of Northeast India. In the study, bio-oil was extracted from Melocanna baccifera through pyrolysis process and was evaluated for their biological properties. The characterization of the functional attributes responsible for the activities was achieved using advance techniques. The extracted bio-oil was found to be smoky dark brown in colour with a pH of 2.46 ± 0.2. Bio-assays showed that the bio-oil was efficient in inhibiting the growth of pathogenic fungal and bacterial strains such as Fusarium udum, F. proliferatum, Micrococcus luteus, and Salmonella typhimurium in a concentration dependent manner. The bio-oil also exhibit excellent free radical scavenging properties even at concentration of 1% and tend to increase with the concentration of the extract. Similar to previous reports, the antimicrobial and antioxidant properties of the bio-oil were attributed to bioactive compounds like Guaiacol, Catechins, Catechol, Quinol, 2-Methoxy-4-methylphenol, etc. which were further validated by gas chromatography, ICP-MS and FTIR characterization techniques. While the extract did not show any significant phytotoxicity effect either on the seed germination rate or root elongation, they were found to promote the development of secondary roots in Vigna radiate. The present findings offer valuable insights for the further exploration and evaluation of bamboo biomass as possible sources of novel bioactive compounds and also extraction of other high-value added products.

Genetic diversity and population structure of Fusarium udum in India and its correlation with pigeonpea wilt incidence.

In a study conducted in India, 50 Fusarium isolates were collected from pigeonpea growing regions and extensively examined for their cultural and morphological characteristics. These isolates exhibited significant variations in traits including growth rate, mycelial growth patterns, color, zonation, pigmentation, spore size, and septation. Subsequently, 30 isolates were chosen for pathogenicity testing on eight pigeonpea genotypes. Results showed distinct reactions, with four genotypes displaying differential responses (ICP8858, ICP8859, ICP8862, and BDN-2), while ICP9174 and ICP8863 consistently exhibited resistance and ICP2376 and BAHAR remained susceptible to wilt disease. To study the interaction between Fusarium isolates and pigeonpea host differentials (HDs), an additive main effects and multiplicative interactionanalysis was conducted. The majority of disease incidence variation (75.54%) was attributed to HD effects, while Fusarium isolate effects accounted for only 1.99%. The interaction between Isolates and HDs (I × HD) contributed 21.95% to the total variation, being smaller than HD but larger than I. Based on HD reactions, isolates were classified into nine variants, showing varying distributions across pigeonpea growing states, with variants 2 and 3 being prevalent in several regions. This diversity underscores the need for location-specific wilt-resistant pigeonpea cultivars. Furthermore, genetic analysis of 23 representative isolates, through internal transcribed spacer region of ribosomal DNA and translation elongation factor 1-αgene sequencing, revealed three major clusters: Fusarium udum, Fusarium solani, and Fusarium equiseti. These findings hold potential for developing location-specific wilt-resistant pigeonpea cultivars and enhancing disease management strategies.

Evaluation of Trichoderma spp. as a plant growth promoter and antagonist of major pulse pathogens

Trichoderma spp. is mostly used for the management of soil-borne diseases and some foliage and fruit diseases in a variety of crop plants. It can help the environment by reducing agrochemical pollution, promoting plant growth, and enhancing plant resistance in addition to preventing plant diseases. Trichoderma spp. also functions as a secure, affordable, efficient, and environmentally friendly biocontrol agent for several crop species. In the present study, we obtained different Trichoderma isolates from rhizospheric soil samples of different locations and tested them for their antagonistic activity against major pulse pathogens. Among seven isolates, three isolates, viz., Pipal TH-2, ATH-Kashipur, and Mz/AP-2 were found to be highly effective by inhibiting the growth of Fusarium udum (64.04 to 78.65%), Fusarium ciceris (77.77 to 82.12%), Sclerotium rolfsii (59.09 to 69.30%), Macrophomina phaseolina (52.42 to 62.72%) and Alternaria alternata (80.12 to 83.22%). These isolates were also tested for growth-promoting traits (PGPR) in the present study and isolates having both plant growth-promoting ability and biocontrol potentiality were selected and preserved for further studies. These isolates of Trichoderma spp. would be a crucial partner for achieving the Green Earth goal due to their contribution to the sustainable growth of agriculture.

Effect of meteorological parameters on the dynamics of wilt and pod borer severity in pigeonpea of Bundelkhand region of Uttar Pradesh

The weather parameters play a predominant role in determining the course and severity of insect pests and pathogens in different crops. Wilt and pod borer are the most devastating biotic stresses, causes huge losses from the vegetative stage until harvest. The present study was aimed to analyze the seasonal dynamics of wilt and pod borer incidence in relation to critical weather parameters in pigeonpea from the Bundelkhand region, a pulses basket of Uttar Pradesh. The fusarium wilt (Fusarium udum) and pod borer (Helicoverpa armigera) incidence were found to be major biotic stresses in pigeonpea from 2017-18 to 2020-21. The wilt disease commenced at 48 MSW and the mean incidence ranged from 0.0 to 25.5 percent. The pod borer incidence started at 01 MSW, and the larval population ranged from 0.5 to 1.40 larvae/plant. Though the correlation between pest incidence and weather parameters was found to be non-significant. The wilt and pod borer incidence were positively correlated with Tmax (r= 0.35 and 0.33), Tmin (r= 0.39 and 0.37), rainfall (r= 0.43 and 0.41) and negatively correlated with relative humidity (r= -0.32 and -0.26). The regression analysis indicated variability in wilt and pod borer incidence due to temperature, humidity and rainfall. The information generated on the pest dynamics of wilt and pod borer in pigeonpea under the influence of weather parameters may be helpful in devising the forecasting models as well as the management practices well in advance so as to avoid yield losses.

Transcriptional Regulation and Characterization of Fusarium udum Responsive NBS-LRR Genes in Pigeonpea (Cajanus cajan (L.) Millsp.

Transcriptional Regulation and Characterization of Fusarium udum Responsive NBS-LRR Genes in Pigeonpea (Cajanus cajan (L.) Millsp.

Incidence of Fusarium oxysporum spp. Udum on Pigeonpea in Bundelkhand Region, India

Survey was conducted of pigeonpea growing areas of 4 districts in Bundelkhand region of Uttar Pradesh during 2019-20. Fusarium udum was found constantly associated with the root samples. This indicates that this fungus, a well-known wilt pathogen, was primarily responsible for the wilt disease of pigeonpea. The average disease incidence ranged between 3.25% to 49.00% from district to districts. The average incidence percentage of wilted plants in Chitrakoot district was 39.06% followed by Banda district 25.67%, Hamirpur district 15.99% and Mahoba district 14.64% respectively. The maximum wilt (Fusarium oxysporum) incidences were recorded in Chitrakoot district followed by Banda, Hamirpur, and Mahoba. Chitrakoot isolate of F. udum was found more pathogenic and caused higher wilt incidence than other isolate. All the isolates differed in their radial growth colony characters on both solid media. It was found that PDA was the best medium in compare to PSA. The Chitrakoot isolate and radial growth was fast growing followed by others. Sporulation was moderate to excellent in different isolates. However, the maximum radial growth was a recorded-on PSA in Chitrakoot isolate and minimum radial growth in Mahoba isolate. The most distinguishing characteristic of the macro conidia are their strongly curved or hooked apices and measure 11-21.12 x 1.95 to 3.78µm.

Unveiling Oil Seed Cakes Ability to Suppress Fusarium Wilt (Fusarium udum Butler) in Pigeonpea (Cajanus cajan L. Millsp.)

Pigeonpea (Cajanus cajan) holds significant economic importance as a versatile crop due to its various uses. It is a valuable source of nutrition for human consumption, rich in protein, dietary fiber, vitamins and minerals. Additionally, pigeonpea plays a crucial role in sustainable agriculture by fixing atmospheric nitrogen and enhancing soil fertility. Fusarium wilt caused by Fusarium udum is an important economic threat to the growers of pigeonpea in India and across the globe. The study was therefore conducted during the years 2017–2019 to determine the impact of the various oil seed cakes on the fusarium wilt of pigeonpea. Seven treatments including different types of oil seed cakes viz., mustard cake, neem cake, linseed cake, mahua cake, sunflower cake, groundnut cake and carbendazim (treated check) were employed by adopting the soil inoculation method. All of the treatments employed notably diminished the incidence of fusarium wilt. Among the treatments, neem cake (T2) was most effective in suppressing disease incidence (73.78% and 76.89%), registering the least plant fatalities (19.05 and 18.02), respectively. Furthermore, treatment (T2) also showed maximum plant height at 120 DAS (151.86 cm and 153.34 cm) and the highest root-nodules count of pigeon pea (5.71, 5.66) respectively in both the cropping years compared to other treatments and untreated control (T0).

Assessment and identification of bioactive metabolites from terrestrial Lyngbya spp. responsible for antioxidant, antifungal, and anticancer activities.

Lyngbya from fresh and marine water produces an array of pharmaceutically bioactive therapeutic compounds. However, Lyngbya from agricultural soil is still poorly investigated. Hence, in this study, the bioactive potential of different Lyngbya spp. extract was explored. Intracellular petroleum ether extract of L. hieronymusii K81 showed the highest phenolic content (626.22 ± 0.65 μg GAEs g-1 FW), while intracellular ethyl acetate extract of L. aestuarii K97 (74.02 ± 0.002 mg QEs g-1 FW) showed highest flavonoid content. Highest free radical scavenging activity in terms of ABTS•+ was recorded in intracellular methanolic extract of Lyngbya sp. K5 (97.85 ± 0.068%), followed by L. wollei K80 (97.22 ± 0.059%) while highest DPPH• radical scavenging activity observed by intracellular acetone extract of Lyngbya sp. K5 (54.59 ± 0.165%). All the extracts also showed variable degrees of antifungal activities against Fusarium udum, F. oxysporum ciceris, Colletotrichum capsici, and Rhizoctonia solani. Further, extract of L. wollei K80 and L. aestuarii K97 showed potential anticancer activities against MCF7 (breast cancer) cell lines. GC-MS analyses of intracellular methanolic extract of L. wollei K80 showed the dominance of PUFAs with 9,12,15-octadecatrienoic acid, methyl ester, (Z,Z,Z) as the most abundant bioactive compound. On the other hand, the extracellular ethyl acetate extract of L. aestuarii K97 was rich in alkanes and alkenes with 1-hexyl-2-nitrocyclohexane as the most predominant compound. Extracts of Lyngbya spp. rich in novel secondary metabolites such as PUFAs, alkanes, and alkenes can be further explored as an alternative and low-cost antioxidant and potential apoptogens for cancer therapy.

Characterization of plant growth-promoting, antifungal, and enzymatic properties of beneficial bacterial strains associated with pulses rhizosphere from Bundelkhand region of India.

The present study was conducted to characterize the native plant growth-promoting rhizobacteria (PGPRs) from the pulse rhizosphere of the Bundelkhand region of India. Twenty-four bacterial isolates belonging to nineteen species (B.amyloliquefaciens, B. subtilis, B. tequilensis, B. safensis, B. haynesii, E. soli, E. cloacae, A. calcoaceticus, B. valezensis, S. macrescens, P. aeruginosa, P. fluorescens, P. guariconensis, B.megaterium, C. lapagei, P. putida, K. aerogenes, B. cereus, and B. altitudinis) were categorized and evaluated for their plant growth-promoting potential, antifungal properties, and enzymatic activities to identify the most potential strain for commercialization and wider application in pulse crops. Phylogenetic identification was done on the basis of 16s rRNA analysis. Among the 24 isolates, 12 bacterial strains were gram positive, and 12 were gram negative. Among the tested 24 isolates, IIPRAJCP-6 (Bacillusamyloliquefaciens), IIPRDSCP-1 (Bacillus subtilis), IIPRDSCP-10 (Bacillus tequilensis), IIPRRLUCP-5 (Bacillus safensis), IIPRCDCP-2 (Bacillus subtilis), IIPRAMCP-1 (Bacillus safensis), IIPRMKCP-10 (Bacillus haynesii), IIPRANPP-3 (Bacillusamyloliquefaciens), IIPRKAPP-5 (Enterobacter soli), IIPRAJCP-2 (Enterobacter cloacae), IIPRDSCP-11 (Acinetobacter calcoaceticus), IIPRDSCP-9 (Bacillus valezensis), IIPRMKCP-3 (Seratia macrescens), IIPRMKCP-1 (Pseudomonas aeruginosa), IIPRCKPP-3 (Pseudomonas fluorescens), IIPRMKCP-9 (Pseudomonas guariconensis), IIPRMKCP-8 (Bacillus megatirium), IIPRMWCP-9 (Cedecea lapagei), IIPRKUCP-10 (Pseudomonas putida), IIPRAMCP-4 (Klebsiella aerogenes), IIPRCKPP-7 (Enterobacter cloacae), IIPRAMCP-5 (Bacillus cereus), IIPRSHEP-6 (Bacillus subtilis), IIPRRSBa89 (Bacillus altitudinis) bacterial isolates, IIPRMKCP-9, IIPRAJCP-6, IIPRMKCP-10, IIPRAMCP-5, IIPRSHEP-6, and IIPRMKCP-3 showed the maximum antagonistic activity against Fusarium oxysporum f. sp. ciceris (FOC), Fusarium oxysporum f. sp. lentis (FOL), and Fusarium udum (FU) causing wilt disease of chickpea, lentil, and pigeonpea, respectively, and maximum plant growth-promoting enzyme (phosphatase), plant growth hormone (IAA), and siderophore production show promising results under greenhouse conditions. This study is the first report of bacterial diversity in the pulse-growing region of India.

Evaluation of organics, antagonists and carbendazim against Fusarium wilt of pigeonpea (Cajanus cajan L.)

In India, pigeonpea [Cajanus Cajan (L.) Millsp.] wilt caused by Fusarium udum is prevalent in all areas it cultivated. Among the major soil borne diseases pigeonpea, the Fusarium wilt caused by Fusarium udum is one of the most important diseases and can cause 30-100% loss in grain yield. A pot experiment was conducted to assess the efficacy of Trichoderma harzianum, Pseudomonas fluorescens, farm yard manure, spent mushroom substrate of oyster mushroom and the fungicide Carbendazim 50% WP against Fusarium wilt of pigeonpea in terms ofseed germination and disease incidence under artificial inoculation conditions during Kharif 2021. Among the treatments assessed, maximum seed germination (95.83%) was recorded in treatments in which seed were treated with Carbendazim 50% WP or soil amended with the combination of spent mushroom substrate+Trichoderma harzianum or spent mushroom substrate+(Trichoderma harzianum+ Pseudomonas fluorescens) prior to sowing. Maximum reduction in disease incidence (73.81%) of Fusarium wilt over the control was recorded in treatment in which soil was amended with combination of spent mushroom substrate+(Trichoderma harzianum+ Pseudomonas fluorescens). The results revealed that all the treatments applied as prophylactic measure, reduced the Fusarium wilt and increased the seed germination significantly over the unprotected crop.

Genetic diversity and antifungal activities of the genera Streptomyces and Nocardiopsis inhabiting agricultural fields of Tamil Nadu, India

Actinomycetes receives much attention as plant-beneficial bacteria due to their distinct morpho-physiological, plant growth promoting and antifungal properties. Among the actinomycetes, members of the genus Streptomyces are of specific interest due to their metabolic versatility and ubiquity. The diversity of Streptomyces in different crop fields of Tamil Nadu has not been explored early. In this study, we explored phylogenetic diversity, morphological heterogeneity, and antifungal properties of cultivable actinomycetes isolated from the rhizosphere and bulk soils of different crops collected from 20 distinct districts of Tamil Nadu. A total of 65 actinomycetes were isolated from 40 soil samples including rhizosphere and bulk soils of different crops, and their diversity was analyzed using the 16S rRNA gene sequence. They were then characterized for cultural characteristics and antifungal activity against four fungal strains Fusarium udum, Fusarium oxysporum f.sp. ciceri, Macrophomina phaseolina and Sclerotium rolfsii. Out of the 65 isolates sequenced, 45 were found to be closely related to Streptomyces spp. while the remaining 20 showed similarities with Nocardiopsis spp. Cultural characterization on four different ISP media showed immense diversity among the members of the genera Streptomyces and Nocardiopsis. The strains of Streptomyces spp. and Nocardiopsis spp. showed varying levels of antifungal activity with all strains found antagonistic against both Fusarium udum and Fusarium oxysporum f.sp. ciceris. All the strains obtained in this study have been accessioned at the National Agriculturally Important Microbial Culture Collection (NAIMCC) to increase the database of characterized strains belonging to these two genera in the collection.

Virulence and pathogenicity determinants in whole genome sequence of Fusarium udum causing wilt of pigeon pea.

The present study deals with whole genome analysis of Fusarium udum, a wilt causing pathogen of pigeon pea. The de novo assembly identified a total of 16,179 protein-coding genes, of which 11,892 genes (73.50%) were annotated using BlastP and 8,928 genes (55.18%) from KOG annotation. In addition, 5,134 unique InterPro domains were detected in the annotated genes. Apart from this, we also analyzed genome sequence for key pathogenic genes involved in virulence, and identified 1,060 genes (6.55%) as virulence genes as per the PHI-BASE database. The secretome profiling of these virulence genes indicated the presence of 1,439 secretory proteins. Of those, an annotation of 506 predicted secretory proteins through CAZyme database indicated maximum abundance of Glycosyl hydrolase (GH, 45%) family proteins followed by auxiliary activity (AA) family proteins. Interestingly, the presence of effectors for cell wall degradation, pectin degradation, and host cell death was found. The genome comprised approximately 895,132 bp of repetitive elements, which includes 128 long terminal repeats (LTRs), and 4,921 simple sequence repeats (SSRs) of 80,875 bp length. The comparative mining of effector genes among different Fusarium species revealed five common and two specific effectors in F. udum that are related to host cell death. Furthermore, wet lab experiment validated the presence of effector genes like SIX (for Secreted in Xylem). We conclude that deciphering the whole genome of F. udum would be instrumental in understanding evolution, virulence determinants, host-pathogen interaction, possible control strategies, ecological behavior, and many other complexities of the pathogen.

Antagonistic Activity of Pseudomonas fluorescens Strain X1 Against Different Fusaria and it’s In Vivo Analysis Against Fusarium udum Infected Pigeon Pea

A plant growth-promoting rhizobacterial strain, Pseudomonas fluorescens X1 isolated from the garden soil was employed for antagonistic activity against different species of fusaria. Strain X1 inhibited four different fusaria (Fusarium moniliforme, Fusarium oxysporum, Fusarium semitectum and Fusarium udum) in dual culture plate assay, and in broth culture using cell-free culture filtrate. Scanning electron microscopic (SEM) analysis revealed deformation and shrinkage in mycelia of fusaria after treatment with strain X1. Confocal micrographs showed degeneration of nuclei inside the cells of fusaria for the same effect. Strain X1 exhibited maximum antifungal activity, when it was grown in nutrient broth yeast (NBY) medium amended with 1mM NH4MoO4 and 1% glucose. The antifungal extracts eluted from thin-layer chromatography (TLC) followed by high performance liquid chromatography (HPLC) showed two fractions active against different fusaria. Liquid chromatography-mass spectrometry (LCMS) analysis of the two fractions 1 and 2 corresponded to molecular ions at m/z 177.16 and m/z 177.09, respectively. Infra-red (IR) analysis showed five similar absorption bands in both the fractions analysed. In vivo analysis of strain X1 alone and along with fungicide inhibited the growth of F. udum and improved the biomass and growth of pigeon pea. These results indicated that strain X1 could be possibly used as a biocontrol agent to inhibit the growth of soil-borne diseases of different fusaria including F. udum that causes wilting in pigeon pea.

Modulation of phenylpropanoid and lignin biosynthetic pathway is crucial for conferring resistance in pigeon pea against Fusarium wilt

To elucidate the role of the phenylpropanoid pathway in the expression of resistance during compatible and incompatible interactions between pigeon pea and wilt-causing vascular pathogen Fusarium udum, we estimated the total phenol content, lignin, phenolic acids and activity of enzymes involved in lignin polymerization of monolignols and examined the expression pattern of lignin biosynthesis genes. Our results demonstrated a higher accumulation of free and cell wall-bound phenolics and total lignin content in the highly resistant pigeon pea genotype ICP 14623 as compared to susceptible genotype ICP 14166. An increased activity of phenylpropanoid pathway-associated defense enzymes such as Phenylalanine ammonia-lyase, polyphenol oxidase, ascorbate and guaiacol- dependent peroxidases in resistant pigeon pea genotypes suggests their role in resistance. Moreover, analysis of lignin biosynthesis genes revealed their differential expression during resistant and susceptible interactions, revealed their crucial role in imparting resistance against wilt. Overall, our results indicated the role of physical and biochemical components of the phenylpropanoid pathway in the expression of resistance in pigeon pea against Fusarium wilt.

Differential transcript expression profiles of susceptible and resistant pigeonpea cultivars at an early time point during Fusarium udum infection.

Differential transcript expression profiles of susceptible and resistant pigeonpea cultivars at an early time point during Fusarium udum infection.

Identification of resistance sources against Fusarium udum (Race-2) in wild accessions of pigeon pea for strengthening the pre-breeding program

Identification of resistance sources against Fusarium udum (Race-2) in wild accessions of pigeon pea for strengthening the pre-breeding program

Assessment of Weather Parameters on Per Cent Disease Incidence and Forewarning Models of Fusarium Wilt in Pigeonpea as Influenced by Different Sowing Windows

Background: Fusarium wilt caused by Fusarium udum (Butler) var. cajani is one of the most important soil-borne diseases of pigeonpea capable of causing 30-100% loss in grain yield. So it is essential to establish the relationship with weather parameters and prediction of per cent disease incidence. Methods: An experiment was laid out in split plot design with three replications and sixteen treatment combinations considering different varieties and sowing windows. Correlation and multiple linear regression equations were elucidated between weather parameters and per cent disease incidence (PDI) of Fusarium wilt on different pigeonpea varieties under different sowing windows during 2017-18 and 2018-19. Result: The correlation of weather parameters with PDI of Fusarium wilt indicated that significant and positively correlation with maximum and minimum temperature and negative correlation with evening relative humidity. Among all sowing windows 30th meteorological week (MW) sowing window with the variety ICPH 2740 PDI for two weeks prior was significantly positively correlated with maximum temperature (0.871** and 0.919**) and morning relative humidity (0.727* and 0.056). The prediction of PDI of Fusarium wilt with multiple linear regression equations were recorded the highest R2 valueas 95.5% in case of treatment combination of 30th MW and the variety Vipula.