Draft Genome of <i>Fusarium oxysporum</i> f. sp. <i>cubense</i> Strain Tropical Race-4 Infecting Cavendish (AAA) Group of Banana in India

Fusarium wilt, caused by the fungus Fusarium oxysporum f. sp. cubense, is the most serious pandemic disease of banana. In this study, we report the draft genome of F. oxysporum f. sp. cubense vegetative compatibility group (VCG) 01213/16 of strain tropical race 4 (TR4) that infects the Cavendish (AAA) group of banana collected from the subtropical region in India. The genome assembly of SFoc TR4 comprises 47,384,463 bp with 4,034 contigs and 15,508 protein-coding regions. Based on VCG analysis, the fungal isolate belongs to F. oxysporum f. sp. cubense TR4 but the genome sequence of SFoc TR4 shows differences in secreted-in-xylem (SIX) protein gene clusters (specifically, SIX8) in comparison with the reference genome of F. oxysporum f. sp. lycopersici and F. oxysporum f. sp. cubense TR4. </jats:p

Not Available

Not AvailableFusarium wilt, caused by the fungus Fusarium oxysporum f. sp. cubense, is the most serious pandemic disease of banana. In this study, we report the draft genome of F. oxysporum f. sp. cubense vegetative compatibility group (VCG) 01213/16 of strain tropical race 4 (TR4) that infects the Cavendish (AAA) group of banana collected from the subtropical region in India. The genome assembly of SFoc TR4 comprises 47,384,463 bp with 4,034 contigs and 15,508 protein-coding regions. Based on VCG analysis, the fungal isolate belongs to F. oxysporum f. sp. cubense TR4 but the genome sequence of SFoc TR4 shows differences in secreted-in-xylem (SIX) protein gene clusters (specifically, SIX8) in comparison with the reference genome of F. oxysporum f. sp. lycopersici and F. oxysporum f. sp. cubense TR4.Not Availabl

Isolation and Characterization of Rhizobium from Green Gram (Vigna radiata)

Nitrogen is a crucial component that acts as building blocks for nucleic acids and proteins. It is abundantly present in atmosphere of the earth but plants are not able to easily utilize it. Diazotrophic microorganisms such as Rhizobium convert N2 and make it available to pulse crops. In the present study, a total of thirty-four Rhizobium isolates were recovered, from that twenty-two with gram-negative-rods were biochemically characterized. Most of the isolates were negative for congo red (CR) absorption, glucose-peptone, lactose, and hofer’s alkaline assays. These isolates have PGP (plant growth promoting) properties such as solubilisation of mineral, growth hormone, and hydrogen cyanide (HCN) productions along with antagonistic activity. Plant study revealed that SBGR25 treatment has highest germination per cent (98.0 %), shoot (10.3 cm) and total-height (16.6 cm), and dry weight (5.60 g). Hence, the present study suggests that SBGR25 strains could be used as promising bioinoculants for the pulse crop.</jats:p

Not Available

Rhizome rot or soft rot disease is one of the major problems in banana (Musa spp.) cultivation, because it causes germination failure and death of early-stage plants. A roving survey conducted during 2017 to 2019 in the major banana growing states of India indicated a 5 to 30% incidence of rhizome rot in commercial cultivars. The symptoms observed were yellowing of leaves, necrotic drying with or without heart rot, and yellow or brown watersoaked spots with dark brown margins in the rhizomes. Decay of tissues, cavity formation, brown ooze with foul smell, and toppling were also observed. To isolate bacteria, dissected diseased tissues were surface sterilized and plated on crystal violet pectate (CVP) medium. Of 60 samples plated on CVP medium, three samples collected from cultivars NeyPoovan-AB (Karur, Tamil Nadu, 10 56936.899N; 78 24912.599E), Grand Naine-AAA (Tiruchirappalli, Tamil Nadu, 10 47926.199N; 78 34914.899E), and Thellachakkarakeli-AAA (East-Godavari, Andhra Pradesh, 16 51932.199N; 81 46908.499E) did not yield any bacteria; however, when plated on nutrient agar, they produced whitish to dull white, mucoid, raised, round, and translucent colonies, and three isolates were named as NPK-3-48, GTC-5, and 1-1B-3, respectively. Because these colonies were distinct from colonies obtained on CVP medium (which were analyzed and confirmed separately as Pectobacterium sp.) (Gokul et al. 2019), they were further characterized. Amplification of 16S rDNA genes of NPK-3-48, GTC-5, and 1-1B-3 isolates using universal primers (27F, 59-AGAGTTTGATCCTGGCTCAG-39; 1492 R, 59- GGTTACCTTGTTACGACTT-39) and rpoB gene (Rosenblueth et al. 2004) was carried out; the amplicons were sequenced and deposited in NCBI (accessions MW036529 to MW036531; MW497572 to MW497574). Phylogenetic analysis of rpoB clearly showed that the isolates NPK-3-48, GTC-5, and 1-1B-3 are Klebsiella variicola (Rosenblueth et al. 2004). Additionally, biochemical tests also indicated that all three isolates were gram negative, catalase positive, oxidase negative, and able to utilize glucose, maltose, and citrate (Ajayasree and Borkar 2018). Therefore, the above morphological, molecular, and biochemical analyses carried out indicated that NPK-3-48, GTC-5, and 1-1B-3 are K. variicola. Earlier, K. variicola causing soft rot has been reported on banana in China (Fan et al. 2016), plantain soft rot in Haiti (Fulton et al. 2020), and carrot soft rot in India (Chandrashekar et al. 2018). For pathogenicity tests, these three isolates were grown in nutrient broth for 48 h at 37 6 1 C, and the cells were harvested by centrifugation. Five milliliters of the culture suspension (2 3 108 CFU/ml) taken in a syringe was injected into rhizomes of 3-month-old tissue-cultured Grand Naine plants. Each bacterial isolate was injected into eight banana plants at soil level. Appropriate controls were maintained. Inoculated plants were maintained in a glasshouse at 32 6 2 C, and after 30 to 35 days rhizome rot symptoms appeared in all three bacterial isolates inoculated plants but in none of the control plants. Koch’s postulates were proved by reisolation and identification. To the best of our knowledge, this is the first report of K. variicola causing rhizome rot disease of banana in India.Not AvailableNot Availabl