Shailesh Gawande - Academia.edu (original) (raw)

Papers by Shailesh Gawande

With a host range spanning vegetables, pulses, grains, fruits, and cash crops such as cotton, the... more With a host range spanning vegetables, pulses, grains, fruits, and cash crops such as cotton, the polyphagous root knot nematode (RKN) Meloidogyne incognita is known globally as the most economically destructive genus of plant parasitic nematodes. During sampling efforts, severe root galling from RKN infestation was observed on cotton as well as several other vegetable crops in Nagpur, Wardha, Chandrapur, Jalgaon, Aurangabad and Yavatmal districts of the Vidarbha region of Maharashtra in Central India. M. incognita has been reported as the predominant nematode species in irrigated cotton growing regions of Northwestern India, but in the surveyed regions, the reniform nematode Rotylenchulus reniformis has been reported instead on cotton as the predominant species. As well, the sampled RKN populations were found in areas with soil characteristics not matching previously reported habitat conditions, pointing to the ability of RKN populations to tolerate and adapt to a wider variety of soil conditions than expected. Race pro ling from differential host studies indicated all six populations to belong to race 3. Maximum likelihood analysis between the sampled populations and catalogued populations of M. incognita from other Indian states, based on the rDNA Internal Transcribed Spacer (ITS) region showed the populations to form a phylogenetic grouping, thus indicating the potential of Indian populations to exhibit increased pathogenicity towards cotton. As it stands, with cotton as the dominant crop of the region alongside other vegetable crops, the found results underscore the need for proactive surveillance of nematode infestations of cotton.

SSRN Electronic Journal, 2022

Indian Phytopathology, 2022

African Journal of Microbiology Research, Apr 16, 2014

Variability among four isolates of Sclerotium delphinii isolated from infected diseased Khirni (M... more Variability among four isolates of Sclerotium delphinii isolated from infected diseased Khirni (Manilkara hexandra); chafa (Plumeria rubra acutifolia) and Jackfruit (Artocapus heterophyllus) plants of Western Maharashtra region of India were studied. This is the first report on presence of S. delphinii species in India. These isolates varied in colony morphology, mycelial growth rate, sclerotia formation period, sclerotia size and color. On the basis of morphological characters, these isolates were identified as S. delphinii and were also confirmed in Indian type culture collection (ITCC), New Delhi. In mycelial compatibility study, isolates of S. delphinii did not intermingle with Sclerotium rolfsii isolates indicating genetic variation among the species. The isolates of S. delphinii also showed distinct differences in their oxalic acid content. The classification and variability was further confirmed using molecular studies. It was observed that only morphological features and MCGs differentiated the Sclerotium species rather than molecular characterization because they shared some common bands of DNA at genetic level, but showed distinctness in morphological and MCGs study.

Journal of entomology and zoology studies, 2019

Indian Journal of Plant Protection, 2015

Since long, natural fibres have been at the crux for the textile industry as a base material for ... more Since long, natural fibres have been at the crux for the textile industry as a base material for making cloth, paper and building materials. As compared to synthetic fibres gaining importance today, natural fibres are a completely renewable resource and, from an environmental point of view, provide many benefits. Similarly, agriculture in accordance with animal husbandry is closely associated with farming community in a cultural and economical ways as livestock rearing and farming is an integral part of rural livelihood. For this forage crops are playing an important role in sustainable livelihood in agriculture. Occurrence of the diseases affects the availability of quality fibre and fodder. Hence, integrated disease management is the best strategy to minimize the fibre and forage crop losses caused by several diseases. These practices are eco-friendly and economical. Sowing of disease-free certified seed is very effective way to reduce disease infection at early stages and possibl...

Soil Biology, 2018

Archaea are the inhabitants of extreme environments on the earth. They commonly live at extreme a... more Archaea are the inhabitants of extreme environments on the earth. They commonly live at extreme acidity, temperature, and alkalinity or in hypersaline water, hot springs, hydrothermal vents, and glaciers and at extreme pressure and radiation. Some of the members live in deep oceans at extreme pressure and temperature above 100 °C. With the advancement of archaeal taxonomy, diversity, and identification of new strains, their functional role has increased in industrial and biotechnological applications in recent years. The extremophilic archaea are well-known sources of extracellular enzymes and biocatalyst and accelerate fermentation process. Some novel antimicrobial compounds and biomolecules have been discovered in certain archaea. Many of archaeal strains have applications in eco-friendly wastewater treatment plants, biodegradation of marshy lands contaminated with organic solvents, and hydrocarbons. In mineralization process, ammonia-oxidizing archaea (AOA) has key role in nitrogen cycle. The long-term preservation of extremely halophilic and thermoacidophilic archaea has been reported successful by L-drying method but it is labile to freeze and freeze-drying. Viability of thermoacidophilic archaea like Thermoplasma sustained at 5 °C for more than 15 years. The halophilic archaea may be preserved in the Petri dishes or in the refrigerator at 4 °C for quite longer periods with proper sealing and in deep freezing at −80 °C with specific media at proper salt concentration in 20% supplemented glycerol. In the case of hyperthermophilic archaea like Pyrococcus furiosus, the glass capillary tube kept over liquid nitrogen with dimethyl sulfoxide is preferred. The lyophilization method of preservation generally results in loss of viability in most of archaea cultures. Likewise, in situ methods of conservation of archaea in their natural habitats become noteworthy since most of archaea are extremophiles in those particular habitats with unique characteristics and specific traits with several applications. Hence, preservation of archaea requires specific preservation techniques for certain groups, and therefore, it is important to be focused on their maintenance, preservation, and conservation. Hence, it is very important for the development of reliable, simple, and durable preservation technique for particular groups of archaea for long-term preservation with stable viability for over the years.

European Journal of Plant Pathology, 2020

During 2018–19, unusually higher incidences of inner cotton boll rot were reported in farmers’ fi... more During 2018–19, unusually higher incidences of inner cotton boll rot were reported in farmers’ fields from cotton growing tracts of Maharashtra. Extensive survey was conducted to investigate these instances of boll rot. An unusual emerging problem in cotton has been associated with reduced boll development and yield. Green bolls with and without any sign of damage were collected from farmers fields and dissected under aseptic conditions. Bacterial species belonging to members of Enterobacteriaceae family (facultative anaerobe) were predominately isolated from rot affected cotton bolls. Four bacterial strains isolated from four locations were identified on the basis of morphological, biochemical and molecular characterization. Pathogenicity of all the four isolates (CBR2-YTML, CBR1-JLGN, CBR2-BLDN and CBR5-JLGN) was proved by Koch’s postulates. To the best of our knowledge, this is the first report of occurrence and association of phytopathogenic bacteria Pantoea dispersa, a member of the Enterobacteriaceae family as a potential and principal pathogenic agent causing inner cotton (G. hirsutum L.) boll rots in Maharashtra state, India.

Plant Disease, 2020

Rosa chinensis Jacq. is a traditional Chinese ornamental plant extensively cultivated in China. I... more Rosa chinensis Jacq. is a traditional Chinese ornamental plant extensively cultivated in China. In April 2018, anthracnose lesions were found on leaves of R. chinensis planted in a garden in Changsha City, China. The symptoms initially appeared as small circular, sunken necrotic lesions. The center of lesions were gray with a pale brown border. As the disease progressed, lesions expanded into 5 to 14-mm-diameter spots and were near round or irregular. To identify the pathogen, pieces of symptomatic tissues were surface-sterilized for 1 min in 1% NaClO, plated on potato-dextrose agar (PDA) with 0.1 mg/ml of ampicillin, and incubated at 25 ± 2℃ in the dark. A Colletotrichum sp. was consistently isolated from diseased tissues. Three different single-spore cultures (RS29, RS30, RS35) were used for fungal morphological characterization and identification. The three isolates showed the same morphological features: colony mycelium was initially white, turning pale gray with time, while the reverse side was dark brown at the center of the plate (Fig 1A-B). The average growth of colonies was 9.8 mm per day (n=7). The hyphae were hyaline. Conidia were straight, hyaline, fusiform to cylindrical, with rounded apices, and ranged from 11.4 to 17.8 μm (mean 14.5 μm) × 2.7 to 5.5 μm (mean 3.8 μm) (n=100) (Fig 1C-D). Appressoria were single or clustered, variable in shape, brown, smooth-walled, and ranged from 4.7 to 6.6 μm (mean 5.5 μm) × 3.6 to 5.4 μm (mean 4.4 μm) (n=50) (Fig 1E). The morphological and cultural traits were consistent with descriptions of C. siamense (Prihastuti et al. 2009; Sharma et al. 2013). To confirm identification, partial sequences of the internal transcribed spacer (ITS), calmodulin (CAL), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), actin (ACT), glutamine synthase (GS), and β-tubulin 2 (beta-TUB-2) genes of the three isolates were obtained and deposited into GenBank with accession nos. MH643994-MH643999 and MK446249-MK446260. A phylogenetic tree generated by neighbor joining using the six gene sequences in MEGA 7 revealed that our isolates clustered in the same clade with C. siamense (Fig. 2) (Weir et al. 2012). Mycelial plugs (5 mm in diameter) from a 7-day-old colony of RS29 were inoculated on ten wounded (using sterile needle) and ten non-wounded leaves, stems, receptacles and calyxes of healthy R. chinensis plants that were previously disinfested with 1% NaClO and rinsed twice with sterile distilled water, respectively. An equal number of plants inoculated with plugs of non-colonized PDA served as the control. Pathogenicity tests were repeated three times. Plants were kept under greenhouse conditions at 25 ± 2℃ and 90% relative humidity on a 12-h fluorescent light/dark regimen. Initial symptoms resembling those in the garden appeared after 3 days on all wounded and inoculated plant tissues, and after 9 days on non-wounded inoculated plant tissues, whereas the control plants remained healthy (Fig 1F-I). The pathogen was re-isolated from inoculated plants, completing Koch's postulates. This is the first report of C. siamense in China causing anthracnose on R. chinensis. The identification of this pathogen provides a foundation for the management of anthracnose in R. chinensis.

South African Journal of Botany, 2020

Abstract Twenty three fungal endophytes isolated from desi cotton (Gossypium arboreum) were evalu... more Abstract Twenty three fungal endophytes isolated from desi cotton (Gossypium arboreum) were evaluated against two important pathogens of cotton Corynespora cassiicola and Fusarium solani, causal agents of leaf spot and seedling rot respectively. The internal transcribed spacer (ITS) region analysis was used for species-level identification of the fungal endophytes, wherein Curvularia (11) genus followed by Nigrospora (4) was found dominant whereas, Alternaria sp. (2) and Setosphaeria rostrata (2) were other prominent endophytes. Two isolates of Nigrospora sphaerica (CEL 5 and CEL 19) were highly efficient against C. cassiicola and inhibited mycelial growth up to 49.38% and 46.30%, respectively, whereas another isolate of N. oryzae (CEL 2) was effective against F. solani with inhibition of 43.06%. Besides, N. sphaerica (CEL 19) was found to influence the growth of test pathogens when tested for antibiosis. Through GC/ MS analysis of CEL 19 isolate, four major antimicrobial volatile organic compounds (VOCs), namely 1, 3‑diethyl benzene, 1, 4-diehtyl benzene, m-Ethylacetophenone, and p-cymene-7-ol were identified. The phylogeny tree constructed based on ITS sequences revealed two major branches and the first major branch consisted of most of the isolated fungal endophytes, whereas the second major branch consisted of only Coprinopsis cinerea and Puccinia chunjii. The 23 isolates divided into Ascomycota and Basidiomycota phyla were represented by four classes; Agaricomycetes, Eurotiomycetes, Sordariomycetes and Dothidiomycetes which were distributed into six orders. The majority of endophytes belonged to class Dothidiomycetes, followed by Sordariomycetes. There was no much difference observed between the endophytes and the reference taxa, even though it was a pathogen, indicating that pathogenicity of an organism is always not correlated with its gene sequence. Our findings suggest that N. sphaerica could be used as a potential biocontrol agent and its VOCs also have a role in suppressing the growth of plant pathogens.

Journal of Phytopathology, 2020

Phytoparasitica, 2019

The pink bollworm Pectinophora gossypiella (Saundars) (Lepidoptera: Gelechidae) has recently emer... more The pink bollworm Pectinophora gossypiella (Saundars) (Lepidoptera: Gelechidae) has recently emerged as a serious menace on Bt cotton in India. Extensive roving surveys were conducted in 83 locations spread across 16 major cotton growing districts of Maharashtra State, India to assess the level of pink bollworm infestation in Bt cotton. The dynamics and severity of pink bollworm damage during the different stages of boll development (90-130 days of crop age) were assessed based on random sampling of green bolls, opened bolls and picked bolls per plant and number of locules damaged per boll. Survey results revealed a widespread infestation of pink bollworm on Bt cotton across the surveyed sites in a range of 40-95% which accounts for anticipated yield losses between 20 and 30%. A typical pattern of progressive increase in the level of pink bollworm infestation and intensification of locular damage with the advancement of the crop season was observed. The pink bollworm hitherto was supposed to be under control since the introduction of Bt cotton in India, now it appears to be widespread, especially on Bt cotton throughout the cotton growing areas of Maharashtra State which shares approximately 36% and 25% of the country's cotton area and production, respectively. This article discusses the implications of serious outbreak of pink bollworm infestations in Bt cotton and also suggest measures necessary to mitigate its potential threat to Indian cotton production. The modulation of management practices aimed at manipulation of cotton cropping pattern being followed in the country in general and Maharashtra in particular could strengthen the management of pink bollworm populations effectively. We discuss the practicality of several management options aimed at achieving this goal.

Journal of Virological Methods, 2019

Progressive Agriculture, 2016

Blights caused by fungi are among the biggest threats in the protected cultivation of many orname... more Blights caused by fungi are among the biggest threats in the protected cultivation of many ornamental and flowering annuals. Gerbera is an important flowering shrub in the greenhouse cultivation. However, gerbera plant is attacked by many fungal pathogens in the protected cultivation and among that A. alternata is a serious one. In the present study, the growth and sporulation of A. alternata was studied under in vitro condition. The in vitro studies by ‘Poisoned Food Technique’ indicated that the fungicides viz., Bordeaux mixture (0.6%) and tricyclazole (0.1%) completely inhibited the growth and sporulation of A.alternata followed by significant effectiveness of difenoconazole (0.1%), propiconazole (0.1%), hexaconazole (0.1%), iprodione + carbendazim (0.1%), captan (0.1%) and mancozeb (0.1%) against the pathogen.

Fungal Biology, 2016

Alternaria spp. of ascomycete fungi are known as major plant pathogens causing 20–80 % agricultur... more Alternaria spp. of ascomycete fungi are known as major plant pathogens causing 20–80 % agricultural losses in field crops, horticultural crops, plantation crops, forest plants and also post harvest storage. Conventional methods of phyto-pathogenic Alternaria spp. identification is only based on their symptomatology of diseases, morphological, physiological and biochemical studies. However, identification based on formae specials, strains, or ecotypes within a species of Alternaria has limitations for accurate diagnostics, identification and detection. The species identification of these pathogenic groups of fungi is somewhat difficult because of their special growth conditions and morphological differences. The advancement of immunological assays and serological methods has shown more sensitivity and accuracy compared with earlier isolation techniques. Enzyme analysis, metabolic profiling and gel electrophoretic mobility of these pathogen proteins found to be useful for the detection of some strains and species. There are different rapid molecular diagnostics available for the detection of pathogenic Alternaria sp. including a range of pathogenic fungi like Fusarium and Macrophomina sp. Various methods based on detection and analysis of the internal transcribed spacer (ITS)-5.8S ribosomal DNA (rDNA) region are designated to be a powerful tool for precise and rapid laboratory diagnosis. However, the developments of polymerase chain reaction (PCR) variants which employ nucleic acid-based diagnostic techniques including reverse transcription (RT)-PCR, nested-PCR, multiplex-PCR, RT-PCR, RAPD and nucleic acid hybridizations are more rapid, sensitive, specific and reliable. Various commercial kits for in situ detections are available with reproducible results in a short time. Recently, with development of DNA micro-array technology and Fourier transform infrared spectroscopy (FTIR) has revolutionized the fungal phytopathogens identification and has become possible to detect different isolates of Alternaria. Nevertheless, the genomics and proteomics studies through bioinformatics tools are also supplementing with promising results. Though, the wide ranges of diagnostics techniques are available for detection, identification and quantification of Alternaria spp., the polyphasic approaches is best and more reliable than only molecular and serological methods. The sensitivity, specificity, rapidity, cost-effectiveness and their on-site suitability determines choice of the diagnostic methods. In management practices, integrated disease management (IDM) including physical, cultural, chemical and biological methods is the best strategy for Alternaria diseases. Judicious use of resistant germplasm and multi target fungicides provides sustainable advantage for management of diseases. However, development of bioinoculents and disease forecasting module will enable better strategies for eco-friendly disease management. Diversified group of fungi that have been reported as opportunistic pathogens, it is imperative that their specific identification be made correctly by an experienced microbiologist or mycologist. The species detection specific to Alternaria and development of diagnostics using molecular tools and technique is an upcoming challenge for the researchers and sustainable plant disease management.

Vegetos- An International Journal of Plant Research, 2013

ABSTRACT The classification and variability among Sclerotium species was studied by using ISSR an... more ABSTRACT The classification and variability among Sclerotium species was studied by using ISSR and RAPD markers. Based on the amplification pattern and reproducibility of eleven RAPD premiers and seven ISSR primers, the delineating variability among the 13 different crops isolates of Sclerotium rolfsii and 4 isolates of Sclerotium delphinii was analyzed. The primer OPB-16 was found to be the best primer for determination of variability among Sclerotium spp. This primer generated at least 17 bands of 230 -1554 base pairs size. Similar results were obtained with IS-8 primer in ISSR marker amplification studies. Though all the isolates of Sclerotium spp. were genetically variable, they share some common bands indicating phylogenetic relationship among them. The ability of primers to high-light the genetic polymorphism between the isolates varied greatly and on the basis of pooled RAPD and ISSR marker analysis these isolates were classified into five broad groups. RAPD-PCR and ISSR molecular marker anal-ysis were found to be efficient and informative technique for differentiating the genetic variability among Sclerotium species.

Efficacy of entomopathogenic fungus, Verticilium lecanii was evaluated against assorted populatio... more Efficacy of entomopathogenic fungus, Verticilium lecanii was evaluated against assorted populations of Bemicia tabaci nymphs in vitro. The nymphal population was subjected to various concentration of bioagent viz., 109 – 106 spores /ml alone and in combination with various oils viz., Neem oil, D-C-Tron plus oil and liquid paraffin oil at 1% concentration, respectively, replicated thrice. Dose mortality (LC50) and time mortality (LT50) response of Whitefly nymphs against various treatments formed the basis of comparison. Dimethoate @ 0.05 per cent, the application of standard check was the most effective treatment amongst the all. In case of bioagent application, V. lecanii @ 109 spores /ml in combination with Neem oil and D-C-Tron plus oil at 1 % concentration, respectively were the promising treatments in terms of lower time to registered 50 per cent mortality in test population and higher mortality inflicted. Higher spore load of fungus was more lethal in terms of mortality inflic...

Sclerotium rolfsii (teleomorph: Athelia rolfsii (curzi) Tu and Kimbrought) is a most devastating ... more Sclerotium rolfsii (teleomorph: Athelia rolfsii (curzi) Tu and Kimbrought) is a most devastating soil borne plant pathogenic fungus, prevalent in warm, temperate and subtropical regions of the world. The pathogen has wide host range of over 500 plant species throughout the world. The pathogen mostly causes collar rot and root rot disease and occasionally causes leaf spot diseases also. Studies on variability within the pathogen Sclerotium rolfsii in the geographical region is important because these form the basis to know the host range of the given species, so as to formulate the cropping systems to avoid the infection or in management of the crop. This helps to know the different subspecies of Sclerotium rolfsii present in this pathogen. Therefore, attempts were made to study the variation in Sclerotium rolfsii regarding morphological, cultural, physiological, pathological, biochemical and genetical variation among the isolates collected from different geographic location of Weste...