RESUMEN
Large cardamom (Amomum subulatum Roxb.) is now affected by several diseases caused by both viruses and fungi. At present, leaf blight is considered a major threat to cardamom cultivation in Sikkim. During the past two decades, cultivation of the crop in this region has dropped by almost 60%. Hence, to quantify the severity of leaf blight damage and identification of the causal organism for the disease, a survey was conducted from May to August 2017 in different large cardamom growing regions of Sikkim. During this survey, a typical symptom of leaf blight was observed on cardamom leaves in many locations. The leaves with blights were collected, surface sterilized, and inoculated on potato dextrose agar (PDA). The pathogen was isolated as pure culture, and on the basis of morphological and microscopic characteristics, the fungus was identified species of Curvularia. Molecular characterization of the fungal isolate with ITS-rDNA partial gene amplification using universal primers (ITS4 and ITS5), showed 100% similarity with Curvularia eragrostidis (family: Pleosporaceae). The fungal isolate and nucleotide sequence was deposited in National Fungal Culture Collection of India (NFCCI), Pune and NCBI with accession numbers NFCCI 4541 and MN710527, respectively. This is the first report on the occurrence of C. eragrostidis pathogen causing leaf blight of large cardamom grown in Sikkim.
Asunto(s)
Amomum/microbiología , Curvularia/patogenicidad , Enfermedades de las Plantas/microbiología , Hojas de la Planta/microbiología , Amomum/genética , Amomum/crecimiento & desarrollo , Curvularia/genética , Humanos , India , Enfermedades de las Plantas/genética , Hojas de la Planta/genética , Hojas de la Planta/crecimiento & desarrollo , SikkimRESUMEN
OBJECTIVE: To analyze the potential risks of fungal contaminants on Panax notoginseng and Amomum tsaoko. METHOD: The primary investigation was conducted in the P. notoginseng and A. tsaoko major production areas in Yunnan. Samples of P. notoginseng and A. tsaoko were collected from drugstores and markets in 3 cities of Yunnan. Dilution-plate method was applied for the isolation of fungi, the obtained species were identified according to morphological and molecular approaches. RESULT: Paecilomyces lilacinus and Penicillium citrinum were dominant on samples of Panax notoginseng. P. lilacinus and Aspergillus flavus were dominant on samples of Amomum tsaoko. CONCLUSION: In Yunnan province, the major fungal contaminants on P. notoginseng are P. lilacinus and P. citrinum and the major fungal contaminants on A. tsaoko are P. lilacinus and Aspergillus flavus. There exists a potential contamination risk of citrinin on P. notoginseng and aflatoxin on A. tsaoko.
Asunto(s)
Amomum/microbiología , Contaminación de Medicamentos , Hongos Mitospóricos/aislamiento & purificación , Hongos Mitospóricos/fisiología , Panax notoginseng/microbiología , China , Contaminación de Medicamentos/prevención & control , Medicamentos Herbarios Chinos , RiesgoRESUMEN
In the present study, nitric oxide synthase/nitric oxide (NOS/NO) status was tested in the host plants infected with fungi, bacteria and virus. In each case cytosolic nitric oxide synthase (Cyt-NOS) of diseased plants was inhibited and inhibition was competitive in nature in respect to l-arginine, the substrate for the enzymic activity. Elevation of host nitric oxide (NO) level before infection using nitric oxide (NO) donor protected disease initiation significantly. The nature of enzyme kinetics and the manner of disease protection by nitric oxide donor (NO-donor) was similar in all the three cases of infection. It was concluded that nitric oxide was a common antipathogenic factor of plants.