Fusarium flocciferum, causing wilt disease of chili (Capsicum annuum L.) in Northern Himalayas: A first report.

In August 2020 chili (Capsicum annuum L.) showing wilt symptoms were collected from different districts of the Kashmir: Pulwama, Srinagar, Baramulla, and Anantnag. From each district one location was selected for sample collection and a total of 23 chili isolates were isolated. The tissue bit technique was used to isolate fungus from the infected samples on potato dextrose agar (PDA) medium, purified using the single spore technique, maintained at 25°±1℃ and then stored at 4° C (Ferniah et al. 2014) . Initially cultural characteristics appeared as white colonies which gradually turned to pale white colored and attained a growth of 90 mm in 18 days of incubation at 25 ± 1°C. Microscopic observations revealed that mycelium was branched and cylindrical, 3.53-4.98 µm in width. Microconidia were ellipsoidal, hyaline, 0-1 septa werepresent, and 6-7 x 3-4 µm in size. Macroconidia were cylindrical, hyaline, 2-6 septa, measuring 20-60 x 40-45 µm in size. Molecular identification of the pathogens with ITS, TEF, and RPB2 was successfully carried out and the fungi was confirmed as Fusarium flocciferum infecting chili. Amplified PCR products were sequenced and were successfully submitted and accessioned in GenBank with accession number OM189458, OM441199, OR484037 for ITS, TEF, and RPB2 gene. To confirm Koch's postulates pathogenicity test was carried out using rhizosphere inoculation technique (Najar et al. 2011, Parihar et al. 2022). In total 7 replications for sand maize meal medium (potting mixture) was prepared by autoclaving 90 g of sand and 10 g of maize meal in 250 ml of erlenmeyer flask comprising 40 ml of distilled water. The spore suspension at 100 µl per pot was inoculated and was mixed with the sterilized potting mixture in a ratio of (2:1) and up to seven days pathogen was allowed to infect the soil (Davey and Papavizas 1962; Hami et al. 2021). Then chili seeds (cv. Kashmir long-1) were sown in infected potting mixture and grown for three weeks to allow the pathogen to infect the host plants. F. flocciferum took six weeks for appearance of symptoms in the infected potted plants. Control mock inoculation of the potting mixture was carried out using water droplets instead of spore suspension at 100 µl per pot. Seven replications were kept for both inoculated and un-inoculated / control mock pots. The plants developed initial symptoms from light green to yellowish discoloration of leaves followed by the drooping, shriveling, and ultimately leading to death. The collar region of the plant was cut vertically and observed that vascular bundles showed brownish spots and discoloration, indicating wilt as the cause of death. The pathogens were re-isolated and inoculated from all infected plants, then compared with their original pure culture inoculated first, which completely resembled based on morphological, cultural, and pathogenic characteristics. No symptoms were observed on control plants. A phylogenetic analysis was also carried out using ClustalW software that grouped the species identified by different genes into different clades. F. flocciferum has been reported earlier in pea, faba bean and bamboo (Kainthola et al. 2022; Sisic et al. 2020) . In solanaceous crops, this species have been explored as wilt pathogens for the first time from India, indicating diversifying nature of Fusarium flocciferum across various hosts including solanaceous crops.

Fusarium chlamydosporum, causing wilt disease of chili (Capsicum annum L.) and brinjal (Solanum melongena L.) in Northern Himalayas: a first report.

Chili (Capsicum annuum L.) and brinjal (Solanum melongena L.) are the most widely grown solanaceous crops in the world. However, their production has reduced over several years due to the attack of various fungal and bacterial pathogens and various abiotic factors. Still, the major constrain in their production are pathogens with fungal etiology, especially the fungal wilt of solanaceous crops. Fusarium oxysporum and Fusarium solani have been previously identified as the pathogens causing wilt disease in chili and brinjal. Recently, a new fungal pathogen F. equiseti has been reported as the causal agent of wilt disease infecting chili. The current study focused on identifying fungal pathogens associated with the wilted plants of chili and brinjal, collected from different parts of the Himalayan region of Kashmir valley, through morpho-cultural and molecular characterization. DNA extraction, PCR amplification, and sequencing were performed on various isolates. DNA barcoding using the internal transcribed spacer region (ITS) was used to identify the pathogen followed by the pathogenicity test. Further confirmation of the pathogen was done by sequencing of transcription elongation factor (TEF) and Calmodulin (CAL2). In current study Fusarium chlamydosporum has been reported as the wilt causing pathogen of chili and brinjal for the first time in Kashmir Himalayas.

MYB-6 and LDOX-1 regulated accretion of anthocyanin response to cold stress in purple black carrot (Daucus carota L.).

AIM: Anthocyanin, an essential ingredient of functional foods, is present in a wide range of plants, including black carrots. The current investigation was carried out to analyse the effect of cold stress on the expression of major anthocyanins and anthocyanin biosynthetic pathway genes, MYB6 and LDOX-1. METHODS AND RESULTS: Five cultivated carrot genotypes belonging to the eastern group, having anthocyanin pigment, were used in the current study. The qRT-PCR analysis revealed that relative gene expression of transcription factor MYB-6 and LDOX1gene was highly expressed upon cold stress compared to non-stress samples. High-performance liquid chromatography-based quantification of Cyanidin 3-O-glucoside (Kuromanin chloride), Ferulic acid, 3,5-Dimethoxy-4-hydroxycinnamic acid (Sinapic acid), and Rutin revealed a significant increase in these major anthocyanins in response to cold stress when compared to control plants. CONCLUSION: We conclude that MYB6 and LDOX1 gene expression increases upon cold stress, which induces accumulation of major anthocyanins in purple black carrot and suggests a possible cross-link between cold stress and anthocyanin biosynthesis in purple black carrot.