Dry Root Rot Of Chickpea Research Articles

Bacillus valezensis: A New Plant Growth Promoting Rhizobacterium for Plant Growth Promotion and Inhibition of Rhizoctonia bataticola for the Management of Dry Root Rot of Chickpea

Background: Chickpea production is threatened by dry root rot disease in recent years. The disease is caused by soil borne fungus Rhizoctonia bataticola (Taub) Butler with its pycnidial stage Macrophomina phaseolina (Tassi) Goid. Bacillus spp. is a rod shaped and gram negative rhizobacterium which is predominant in the soil. Hence, considering the economic importance of disease, the present investigation was carried out to repress the pathogen by using indigenous Bacillus spp. strains related to antagonistic potential and plant growth promoting traits Methods: Thirty indigenous bacterial PGPR strains were isolated from healthy rhizospheric soil samples of chickpea and their antagonistic potential was studied. Later, the potential ones were examined for plant growth promoting traits. The promising strains were identified at molecular level 16S rDNA. Results: All thirty PGPR strains of rhizospharic Bacillus were potentiality antagonistic against R. bataticola and nine strains showed more than 50 per cent inhibition of the pathogen. Out of nine strains, four strains recorded more growth promoting traits and they were identified at molecular level as Bacillus cereus, Bacillus velezensis, Bacillus subtilis and Bacillus subtilis sub sp. Subtilis. Bacillus valezensis is a new report on rhizosphaeric PGPR against R. bataticola in chickpea.

Indigenous bacterial endophytic PGPMs of chickpea: Characterization and hidden antagonistic potential against <i>Rhizoctonia bataticola</i> causing dry root rot of chickpea

Chickpea (Cicer arietinum L.) is grown in more than 50 countries. India is the largest chickpea-producing country accounting for 64% of the global chickpea production. However, the production is contrained by the dry root rot disease caused by Rhizoctonia bataticola. Considering this problem, the investigation was carried out to isolate, characterize and the antagonistic potential of indigenous endophytic PGPMs for one of the components in the integrated management of dry root rot of chickpeas in eco-friendly manner. Hence, the isolation of thirty endophytic PGPMs was carried from chickpea by using the spread plate technique. The cultural characters and Gram’s staining reaction confirmed that the endophytic PGPMs isolated from chickpea plant tissues were bacteria. Among thirty bacterial strains, eight showed more than 50% of mycelial inhibition of the pathogen. Out of eight strains, five highly superior strains were selected and subjected for 16S rDNA gene sequencing using the universal primers (16Sr DNA F and 16Sr DNA R), which produced amplified products of size 1500 bp. nBLAST results of 16S rDNA gene sequence revealed that all the endophytic bacterial PGPMs showed homology with genus Bacillus but with different species. The five potential strains namely, BEPGPM-5, BEPGPM-9, BEPGPM-27, BEPGPM-28, and BEPGPM-30 were identified and confirmed as B. tropicus, B. pacificus, B. cereus, B. subtilis, respectively, based on molecular technique.

Identification of Resistant Genotypes and Integrated Management of Dry Root Rot of Chickpea

Background: Dry root rot is an economically important soil borne disease of chickpea in India. The pathogen, Rhizoctonia bataticola, is a soil borne fungus resulting in significant losses in yield. Therefore, the present investigation was aimed to identify the management strategy of disease through identification new sources of resistance and integrated management of disease. Methods: R. bataticola was isolated and purified by using hyphal tip technique and molecular detection was done by using ITS primers. One hundred chickpea germplasm entries were screened under in both field and advanced phenotyping in glass house. The field trials on integrated management of the disease were conducted with different treatments using randomized block design. Result: Fourteen resistant and five moderately resistant genotypes were identified under artificial epiphytotic conditions. Advanced screening of these 19 genotypes under phenotyping technique yielded four resistant and five moderately resistant genotypes. Among nine treatments, seed treatment with mancozeb 50% + carbendazim 25% WP @ 3.5 g/kg followed by soil drenching of mancozeb 50% + carbendazim 25% WP @ 3 g/l water to infected and surrounding plants was found highly effective by recording least disease incidence with highest seed yield, test weight and benefit cost ratio.

Screening of Different Bioagents and Fungicides against Dry Root Rot of Chickpea Incited by Macrophomina phaseolina (Tassi) Goid

Background: Dry root rot of chickpea caused by Macrophomina phaseolina (Tassi) Goid is a serious biotic constraint for chickpea production in Rajasthan. For the management of soil borne disease like dry root rot of chickpea, by using fungicides alone is not feasible due to environmental and health hazards. Hence integrated management of the disease by using bio-agents and fungicides is the best alternative. Therefore, in the present investigation, our main emphasis was to identify best fungicide and bio-agent for management of dry root rot in chickpea. Methods: Eight fungicides and four bio-agents were evaluated against dry root rot pathogen (M. phaseolina) in lab as well as in field condition. The experiment was conducted at instructional farm, COA, SKRAU, Bikaner during Rabi-2019 on most popular cv. GNG-1581 in RBD design with the application of seed treatment and soil application of different bio-agents and fungicides at different concentrations against dry root rot disease and compared with an untreated control. Result: Among all the fungicides used in the present investigation, tebuconazole 50% + trifloxystrobin 25% was found most effective in inhibiting the mycelial growth of the pathogen. Among all the bio-agents, T. harzianum was found most effective in inhibiting the mycelial growth of the pathogen. Under field condition, tebuconazole 50%+ trifloxystrobin 25% WG as seed treatment @ 1.5 g/kg along with T. harzianum @ 10 kg/ha as soil application gave maximum (83.76 %) disease control with highest pod yield (19.5 q/ha) and net return (Rs 39,826/ha). These treatments can provide an effective and economical management of dry root rot disease for chickpea cultivators.

In vitro evaluation of bioefficacy of novel fungal endophytes against Rhizoctonia bataticola (Taub).Butler causing dry root rot of chickpea

Dry root rot is an emerging disease posing threat to chickpea cultivation around the world. It is caused by the soilborne pathogen Rhizoctonia bataticola. The current study was conducted to investigate the potential of employing endophyticmicroorganisms that are antagonistic to R. bataticola to manage dry root rot. A total of 18 fungal endophytes were isolatedfrom healthy chickpea plant (stem and root). The isolated fungal endophytes were evaluated against R. bataticola by dualculture technique under In vitro conditions. Isolate IFRE 2 (Trichoderma yunnanense) exhibited the maximum inhibition ofpathogen growth, followed by BFRE 3 (Trichoderma simmonsii) and IFSE 2 (Trichoderma rifaii). The least mycelialinhibition was observed in BFRE 2 followed by IFSE 4. The effective endophytes were further evaluated for theirbioefficacy against dry root rot under glasshouse conditions as a component of integrated disease management

Morpho-pathogenic and molecular diversity among Rhizoctonia bataticola isolates causing dry root rot of chickpea in Madhya Pradesh, India

Aim: The present study was conducted to identify the morphological, pathological and molecular variations in isolates of Rhizoctonia bataticola, causing dry root rot of chickpea collected from different parts of Madhya Pradesh, India. Methodology: The isolation, purification and identification of Rhizoctonia bataticola isolates was done from dry root rot infected chickpea plants, collected from 23 districts of Madhya Pradesh, India. Total 32 isolates of pathogen were obtained and further used for morphological, cultural, pathological and molecular characterization. The acquired data were subjected to DARwin5 software analysis for variability studies. The DNA isolates of the pathogen were also obtained and analysed to study molecular variability by RAPD analysis and the bands produced were subjected to PAST software for cluster analysis. Results: Thirty two isolates of R. bataticola with diverse origin showed a large variation in shape, size and initiation time of sclerotia. These isolates were pathogenic and grouped into three categories; highly virulent (59%), moderately virulent (25%) and less virulent (16%), under artificially inoculated conditions in sick soil method. The study of pathogenic variability revealed that ICC12441, ICC11332 and Pusa 212 were susceptible to all the isolates evaluated, whereas ICC12450, Pusa362, Pusa1103 showed moderate resistance against maximum isolates. Based on molecular characterization, the isolates were grouped into four clusters indicating that no two or more isolates were similar. Interpretation: The isolates of R. bataticola of chickpea from different agro-climatic zones of Madhya Pradesh, possess variability in their morphological and cultural characteristics, which not limited to geographical boundaries. The present study would be extremely useful for dry root rot management, as well as, in identifying donors for resistance breeding programmes. Key words: Chickpea, Diversity, Dry root rot, Pathogenicity, Rhizoctonia bataticola

Resistance screening and in-vitro efficacy of fungicides for the management of dry root rot of chickpea caused by Rhizoctonia bataticola

Dry root rot caused by Rhizoctonia bataticola (Taub.) Butler is an emerging threat for chickpea production. It is among one of the chief and common soil borne diseases of chickpea. The present investigation was conducted firstly to identify the resistant source for dry root rot in chickpea and secondly to evaluate the efficacy of different fungicides in inhibiting the growth of R. bataticola under in vitro conditions. Screening of a set of 50 chickpea entries resulted in identification of three entries namely ICCV 191317, ICCV 191306, and Ujjain 21 as moderately resistant to dry root rot of chickpea. No entry could be identified as completely resistant for dry root rot in chickpea. Further, among the different fungicides tested, pyraclostrobin alone and in combination of Thiophanate methyl completely checked the growth of R. bataticola at 100 ppm concentration under in vitro conditions. However, another combination product of fungicides namely carboxin + thiram and carbendazim + mancozeb also showed complete inhibition in growth of test pathogen at higher concentration of fungicides i.e. at 300 ppm concentration.The identified moderately resistant genotypes could be a useful resource for development of resistant varieties in chickpea for dry root rot using molecular breeding approaches.

Morphological, molecular and pathogenic characterization of Rhizoctonia bataticola isolates causing dry root rot of chickpea in Turkey

Nineteen chickpea isolates of R. bataticola were obtained from different locations of Turkey in 2016–2017. The isolates were examined for their morphology, genetic and virulence characteristics. The colony color of 10 isolates was grayish black and rest of them was black. Eleven isolates had appressed colony texture, while 3 isolates had velvety and 5 isolates had fluffy. Eight isolates produced aerial mycelium and the other did not. Eight isolates were categorized as fast growing, 8 isolates were categorized as medium growing and 3 isolates were categorized as slow growing. The mean sclerotial sizes of the isolates varied between 65.6 and 127.4 µm. The sclerotia of the 11 isolates were round, 3 isolates were ovoid and 5 isolates were irregular shaped. The size of the PCR products varied from 435 to 518bp and the isolates showed between 99.61 and 100% identity with the reference. The isolates were highly variable in their morphological, molecular and virulence characteristics.

Dry Root Rot of Chickpea: A Disease Favored by Drought.

Chickpea is an essential crop for protein nutrition and is grown around the world in rain-fed conditions. However, chickpea cultivation is under threat due to emerging diseases favored by drought stress. Dry root rot (DRR), an economically devastating disease, is an example. Chickpea-specific strains of a necrotic fungal phytopathogen, Macrophomina phaseolina, cause DRR. Microsclerotia of this fungus, which are capable of withstanding harsh environmental conditions, serve as primary inoculum. Initial symptoms are scattered necrotic spots in roots, progressing to rotting and withering lateral roots, accompanied by prematurely dried, straw-colored foliage. The recent rise in global temperature and worsening of drought spells have aggravated DRR outbreaks in chickpea. To date, DRR epidemiology has not been clarified in detail. Also, the literature lacks clarity on M. phaseolina taxonomy, morphology, disease progression, and diagnosis. In this article, research progress on patterns of DRR occurrence in the field and belowground and aboveground symptoms are clarified. In addition, the current understanding of taxonomy and management practices is elaborated. We also summarize knowledge of the impact of drought and high temperature on DRR severity. Furthermore, we provide future perspectives on the importance of host resistance, quantitative trait loci identification, and genotype screening for the identification of resistant genotypes. The article proposes new research priorities and a corresponding plan for the mitigation of DRR.

Evaluation of fungicides, plant extracts and bio-agents against dry root rot of chickpea (Cicer arietinum)

Dry root rot (DRR) of chickpea caused by Macrophomina phaseolina is an important disease affecting chickpea production especially in tropical and sub-tropical ecologies of world. The present investigation was planned to evaluate the in vitro efficacy of various fungicides, plant extracts and bio-control agents against Macrophomina phaseolina. Results suggested that among fungicides, significantly maximum mean mycelium growth inhibition was recorded with Carbendazim (100%) followed by Carbendazim+Mancozeb (84.65%). Likewise, among phyto extracts, garlic extract was excellent with maximum mycelia growth inhibition (70.15 and 100 %) followed by neem extract (68.35 and 82.35%) at 5 and 10% concentration, respectively. Among bio-agents, Trichoderma viride showed significantly maximum mycelia growth inhibition (80.20%) followed by Trichoderma harzianum (65.10%). Therefore, from the findings of present study, it can be concluded that apart from use of fungicides (Carbendazim and Carbendazim+Mancozeb) phyto extracts such as extract of garlic and neem leaves and bio-control agent Trichoderma viride can also be used as an effective alternative for management of DRR in chickpea. Findings of our study may help in development of sustainable management strategies against DRR thus minimizing its yield consequences in chickpea. However, there is a need to further strengthen the investigations on this aspect based on thorough understanding of the biology of the pathogen and host×plant×environment interaction especially under field conditions.

Occurrence and Distribution of Dry Root Rot of Chickpea Caused by Macrophomina phaseolina (Tassi) Goid. in Arid Region of Rajasthan

Background: Dry root rot of chickpea caused by Macrophomina phaseolina (Tassi) Goid. is emerging as a serious threat to the chickpea production worldwide. The disease is gaining importance under the changing scenario of climate particularly in the rainfed ecologies of India and in arid and semi-arid region of Rajasthan. The current study was aimed to discusses current status of the disease and role of different factors in disease development to help in searching of possible management options for researchers to alleviate the problem. Methods: A roving survey was conducted to record the occurrence and distribution of dry root rot in ten major chickpea growing districts of Rajasthan during Rabi season 2014-15 and 2015-16. In each district, minimum three locations/villages were selected, in each location/village minimum three fields were selected and the incidence of disease was recorded after counting the diseased and healthy plants. Result: Overall range of disease incidence in all the districts vary from 5.75 to 12.51 per cent with an average of 9.15 per cent in Rajasthan. The maximum disease incidence 12.51 per cent was observed in Jaisalmer district while minimum in Ajmer district. The disease was found very common in sandy and sandy loam soil than any other types of soil. The deshi/local varieties were found to be more susceptible to infection of M. phaseolina as compared to improved varieties. Disease incidence was also observed higher in sprinkler system of irrigation as compared to flood method and rainfed conditions. The maximum disease incidence was observed in plants at flowering and podding stages in the months of February and March.

Efficacy of fungicides on dry root rot of chickpea under field condition

An experiment was conducted on efficacy of fungicides of chickpea dry root rot incited by Rhizoctonia bataticola (Taub.) Butler has been emerging as a potential threat in last decades for successful and profitable chickpea cultivation because the pathogen is soil borne nature. The present investigation conducted at chickpea dry root rot hot spot area under natural conditioning Harda district of Madhya Pradesh during rabi 2017-18. The data evident that the spraying of Trifloxystrobin 25% + Tebuconazole 50% @ 500g ha-1 proven most effective for reducing dry root rot incidence in chickpea followed by Propiconozole 25 EC@ 500g ha-1, Tebuconazole 250 EC (25.9% W/W) @625 ml ha-1, Metalaxyl 4%+ Mancozeb 64% @ 1000g ha-1, and Pyraclostrobin 20 WG @500g ha-1 compare to control, while, the incidence of dry root rot noticed minimum 1.50, 2.25, 3.75, 9.50 and 11.50 per cent respectively, although, the incidence 60.75 per cent chickpea dry root rot was noticed in control in respect to management of the diseases, while, Pyraclostrobin 20 WG was found least effective in minimizing the disease incidence. The grain yield maximum 23.25 q ha-1, while, least grain yield 8.75 q ha-1 was harvested in control. Apart from this, the Benefit Cost Ratio 1:2.76 and 1:1.18 was noticed in Trifloxystrobin25% + Tebuconazole 50% and control treatment, respectively.

Management of Dry Root Rot in Chickpea (Cicer arietinum L.) Caused By Macrophomina phaseolina by Utilizing Host Plant Resistance, Fungicides and Bioagents

Background: For the management of soil borne disease like dry root rot of chickpea caused by Macrophomina phaseolina, by using fungicides alone is not feasible due to environmental and health hazards. Hence integrated management of the disease by using resistant varieties, fungicides and bio-control agents is the best alternative. So the present study was aimed to identify resistant varieties, best fungicide and bioagent for management of dry root rot in chickpea. Methods: Two hundred and twelve genotypes were screened using blotter paper technique for identifying resistant genotypes for dry root rot. The experiment on management of dry root rot was conducted during Kharif and Rabi of 2013-14 using a susceptible chickpea variety JG-11 with 14 treatments including control with 3 replications. Result: Of two hundred and twelve chickpea genotypes screened for host plant resistance against Macrophomina phaseolina by blotter paper technique only one genotype ie. PBG-5 showed moderately resistant reaction. Among fourteen treatments including fungicides and bioagents imposed for the management of dry root rot, seed treatment with tebuconazole @ 2 g/kg recorded lowest per cent disease incidence of 9.43, with a highest yield of 722.81 kg/ha compared to untreated control which recorded the highest per cent disease incidence (40.10) with a lowest mean yield of 362.02 kg/ha.

Effect of organic and inorganic sources of carbon and nitrogen on growth and sclerotial production of Rhizoctonia bataticola causing dry root rot of chickpea

Studies on effect of organic and inorganic sources of carbon and nitrogen on growth and sclerotial production of Rhizoctonia bataticola causing dry root rot of chickpea was carried out in vitro and results indicated that All the carbon and nitrogen sources tested exhibited a wide range of sporulation from poor (+) to excellent (++++). However, carbon sources viz., Dextrose, Sucrose and Cellulose recorded excellent (++++) sporulation and nitrogen sources viz., Sodium nitrate, Potassium nitrate and Peptone recorded excellent (++++) sporulation.

Management of dry root rot of chickpea through botanical, plant bi-product and bio-control agent

Gram or Chickpea (Cicerarietinum Linnaeus), a member of family Fabaceae. It is ranked 3rd after common bean (Phaseolus vulgaris L.) and pea (Pisumsativum L.). Chickpea is attacked by 172 pathogens (67 fungi, 22 viruses, 3 bacteria, 80 nematodes and mycoplasma) from all over the world (Nene et al. 1996). The experiment on confirmation of pathogenicity of Rhizoctoniabataticola on chickpea was conducted under pot conditions after growing the test fungus on gram straw, soaked in 0.5 per cent dextrose solution and then mixing it with the sterilized pot soil. The pathogenicity of Rhizoctoniabataticola on chickpea was confirmed by growing the fungus on gram straw soaked in 0.5 dextrose and then mixing at with pot soil. The symptoms appeared within 13 days and the plants were killed within 16 days after sowing the test fungus was recovered from the roots of diseased plants. The results obtained during the course of investigations that in vitro evaluation of plant leaves extracts neem was recorded to be superior in inhibiting the mycelial growth of R. bataticola. At all the concentrations under test Eucalyptus and Jatropha were also found superior in inhibiting the fungus under laboratory conditions but their efficacies declined as the time lapsed. The wilt symptoms on chickpea appeared within 13 days and the plants were killed 16 days after sowing. The roots of the plants showed typical browning at the color region which advanced further and disintegrate the roots.

Effect of soil moisture regimes and soil types on incidence of Rhizoctonia bataticola causing dry root rot of chickpea

Effect of different soil moisture regimes and soil types on incidence of Rhizoctoniabataticola causing dry root of chickpea (Cicerarietinum L.). crop were studied during 2018-19 at VNMKV, Parbhani. In present studiesdry root rot disease incidence was higher (range: 80.00 to 74.45 per cent) at the soil moisture level of 55 to 60 per cent. Whereas it was noticed that sandy soil showed highest dry root rot disease incidence followed by sandy loam soil and than the other soil types.

Integrated control of dry root rot of chickpea caused by Rhizoctonia bataticola under the natural field condition

The study investigated the effect of three fungicides Bavistin®, Aliette®, and Biomagic® at the rate of 2 g/L were tested In vitro and In vivo to control dry root rot and their impact on yield were evaluated at the rate of 4 g/L against R. bataticola while varieties used were Karak-1, Karak-2, Karak-3, and Sheenghar. Disease severity was recorded lowest (19 %) and highest yield (1467 Kg/ha), plant height (47.5 cm), number of pods/plant (15.0) and number of grain/pods (1.66) were recorded in cultivar Karak-1. Among the fungicides drugs, the Bavistin®, significantly reduced the disease severity (5 %) and Kg/ha), highest plant height (64.1 cm), highest grain yield (1488 Kg/ha), number of pods/plant (24.5) and number of grain/pods (2.25). It is concluded that the integrated use of Karak-1 and Bavistin®, fungicide drugs gave promising results for controlling dry root rot of chickpea, and increased plant height, number of pods/plant and number of grain/pods.

Evaluation of non-rhizospheric endophytic bacteria for the management of dry root rot of chickpea

Chickpea (Cicer arietinum L.) is an important pulse crop in India and chief source of dietary protein in the vegetarian diet. The important Destructive disease in chickpea is dry root rot caused by necrotrophic fungus Rhizoctonia bataticola (Taub.) Butler emerging as a serious threat to the production worldwide. The screening of endophytes of leaf and stem isolates under dual culture used as two media PDA and TSA. The 12 isolates are significant on but three isolates are EBS-2, EBS-3, EBS-4 higher suppression towards on Rhizoctonia bataticola. These three isolates used as further methods that roll towel method (vitro) and net house (Pot Cultivation). The roll towel observations to be recorded as Germination percentage, Root, shoot lengths and vigour index. The EBL-3 and EBL-4 with highest germination percentage, Root length were EBL-2, 3 and shoot length, vigour index of EBL-3 highest percentage. The effect of EB on Rhizoctonia bataticola under pot culture observations were recorded that phenological parameters are Germination percentage, Pre-Post, Total mortality, Shoot, Root lengths and Fresh dry weights with different cohabitation on disease incidence. The cohabitation of T8EBL (2+3+4) T7EBL (4+2) are significant on four genotypes JG14, JG16, JG62 and JG315 with inoculation of pathogen. The EBL-3 isolate is that significant correlates in field and lab conditions.

First Report of Macrophomina phaseolina Causing Dry Root Rot of Chickpea (Cicer arietinum) in Serbia

HomePlant DiseaseVol. 103, No. 10First Report of Macrophomina phaseolina Causing Dry Root Rot of Chickpea (Cicer arietinum) in Serbia PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of Macrophomina phaseolina Causing Dry Root Rot of Chickpea (Cicer arietinum) in SerbiaD. Živanov, S. Tančić Živanov, N. Nagl, A. Savić, S. Katanski, and D. MilićD. Živanov†Corresponding author: D. Živanov; E-mail Address: dalibor.zivanov@ifvcns.ns.ac.rshttp://orcid.org/0000-0002-1011-6715Institute of Field and Vegetable Crops, Novi Sad, SerbiaSearch for more papers by this author, S. Tančić Živanovhttp://orcid.org/0000-0001-9556-2732Institute of Field and Vegetable Crops, Novi Sad, SerbiaSearch for more papers by this author, N. NaglInstitute of Field and Vegetable Crops, Novi Sad, SerbiaSearch for more papers by this author, A. SavićInstitute of Field and Vegetable Crops, Novi Sad, SerbiaSearch for more papers by this author, S. KatanskiInstitute of Field and Vegetable Crops, Novi Sad, SerbiaSearch for more papers by this author, and D. MilićInstitute of Field and Vegetable Crops, Novi Sad, SerbiaSearch for more papers by this authorAffiliationsAuthors and Affiliations D. Živanov † S. Tančić Živanov N. Nagl A. Savić S. Katanski D. Milić Institute of Field and Vegetable Crops, Novi Sad, Serbia Published Online:24 Jul 2019https://doi.org/10.1094/PDIS-03-19-0652-PDNAboutSectionsSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Macrophomina phaseolina (Tassi) Goid has been reported as a severe pathogen of many plants worldwide (Mengistue et al. 2015), as well as in Serbia (Tančić Živanov et al. 2018). However, there has been no formal report of M. phaseolina causing dry root rot of chickpea (Cicer arietinum L.) in Serbia. In June 2018, the first symptoms were observed on affected field plants grouped in patches on approximately 10% of chickpea plants in a 3-acre area at Rimski Šančevi, Serbia. Withering and death of aerial parts and root rot were observed on chickpea plants at the V6 growth stage. Cuttings from symptomatic root tissues of five chickpea plants were surface disinfected with 1% NaOCl solution for 5 min, rinsed three times in sterile distilled water, air dried on sterilized filter paper, and plated on potato dextrose agar (PDA) and water agar amended with 100 mg/liter of streptomycin sulfate (Sigma-Aldrich). After 7 days of incubation at 28°C in the dark, isolates were preliminarily identified according to their morphological characters, as hyaline mycelia that turned from gray to dark with age and produced black pigmentation in agar caused by masses of dark oblong microsclerotia formed 3 days after incubation (Watanabe 2010). A representative isolate (K349) was purified by a hyphal-tip transfer technique for further analyses (Leslie and Summerell 2006). To confirm the morphological identification, the rRNA internal transcribed spacer (ITS) region of the isolate K349 was amplified with universal primers ITS1 and ITS4. The resulting ITS sequence (GenBank no. MK418768.1) was used in a BLAST search of the NCBI nucleotide database and showed 100% identity with M. phaseolina isolates (e.g., GenBank nos. KJ744350.1, KP784426.1, KU831518.1, etc.). Translation elongation factor 1-alpha gene (TEF1-α) was amplified using primers EF1-728 and EF1-986, and the resulting sequence (GenBank no. MK430416) had 97.2 to 99.5% identity with M. phaseolina isolates (e.g., GenBank nos. MH000354.1, MG434668.1, KX400854.1, etc.). After the amplification with primers MpKF1 and MaKR1, specific for M. phaseolina (Babu et al. 2007), a 350-bp PCR fragment was obtained, indicating that the isolate K349 was indeed M. phaseolina. The pathogenicity was confirmed according to Koch’s postulates. Chickpea seeds were surface disinfected with 1% NaOCl, air dried, and planted in 10-cm-diameter pots filled with sterilized potting mixture. In total, 10 plants (one per pot) were maintained in the growth chamber at a constant temperature of 25°C, 14-h photoperiod, with relative humidity 100%. Eight-day-old plants were inoculated with three PDA plugs of 5 mm diameter around the exposed stem base of each plant and covered with sterile soil mixture. PDA plugs without mycelia were used for control plants. After inoculation, plants were incubated under growth chamber conditions at 28°C with 14-h photoperiod and watered regularly. The first symptoms observed were wilting leaves and discoloration around the stem base 16 days after inoculation, whereas the control plants remained symptomless. The pathogen was successfully reisolated from the stem base and confirmed as M. phaseolina. To the best of our knowledge, this is the first report of M. phaseolina causing root rot on chickpea in Serbia.The author(s) declare no conflict of interest.

Evaluation of Botanicals and Bio-Agents Against Rhizoctonia Bataticola Causing Dry Root Rot of Chickpea

Evaluation of Botanicals and Bio-Agents Against Rhizoctonia Bataticola Causing Dry Root Rot of Chickpea