Thirteen isolates of Botryodiplodia theobromae collected from pear varieties grown in various regions of Punjab were studied for morphological, pathological and molecular characterization. The mycelial growth of B. theobromae isolates was classified as fluffy or depressed, uniform to irregular and cottony white turning to black. Colony growth rate varied from 19.1 to 24.9 mm per day. Pycnidia were produced either on the edge, centered or scattered on Petri dishes after 20 to 34 days of incubation. Pycnidia and pycnidiospores ranged in size from 118.0 to 240.0 microm and 14.5-35.5 x 6.5-14.5 microm, respectively. Lesion length produced by different isolates ranged from 1.9-7.2 x 0.8-3.3 cm with 49.4-90.9% infection. Using nine SSR and seven RAPD markers, amplified DNA bands ranged from 0.2 to 1.5 and 0.18 to 2.0 kb, respectively. Polymorphism information content values ranged from 0.44 to 0.71 and 0.63 to 0.93 for SSR and RAPD markers, respectively. A dendrogram based on molecular data, grouped the isolates into three major clusters with 65 to 79.5% genetic similarity; most of the isolates showed variety-specific grouping. The isolates prevalent on pear cultivars 'Patharnakh' and 'Baggugosha' in Ludhiana, Amritsar and Hoshiarpur districts were found to have a high degree of similarity; these isolates were also considerably distant from mango isolates and from other isolates on other pear cultivars. The isolates from cultivars Punjab Beauty, LeConte and Kieffer also had a high degree of similarity. Isolates from cultivar Smith were different from other pear isolates but showed more similarity with mango isolates.
The less phytopathogen susceptibility in Himalayan Brassica rapa L. has made it an exceptional crop eluding synthetic pesticide inputs, thereby guarantying economically well-founded and ecologically sustainable agriculture. The relevance of niche microflora of this crop has not been deliberated in this context, as endosymbiosiome is more stable than their rhizosphere counterparts on account of their restricted acquaintance with altering environment; therefore, the present investigation was carried out to study the endophytic microfloral dynamics across the B. rapa germplasm in context to their ability to produce chitinase and to characterize the screened microflora for functional and biochemical comportments in relevance to plant growth stimulation. A total of 200 colonies of bacterial endophytes were isolated from the roots of B. rapa across the J&K UT, comprising 66 locations. After morphological, ARDRA, and sequence analysis, eighty-one isolates were selected for the study, among the isolated microflora Pseudomonas sp. Bacillus sp. dominated. Likewise, class γ-proteobacteria dominated, followed by Firmicutes. The diversity studies have exposed changing fallouts on all the critical diversity indices, and while screening the isolated microflora for chitinase production, twenty-two strains pertaining to different genera produced chitinase. After carbon source supplementation to the chitinase production media, the average chitinase activity was significantly highest in glycerol supplementation. These 22 strains were further studied, and upon screening them for their fungistatic behavior against six fungal species, wide diversity was observed in this context. The antibiotic sensitivity pattern of the isolated strains against chloramphenicol, rifampicin, amikacin, erythromycin, and polymyxin-B showed that the strains were primarily sensitive to chloramphenicol and erythromycin. Among all the strains, only eleven produced indole acetic acid, ten were able to solubilize tricalcium phosphate and eight produced siderophores. The hydrocyanic acid and ammonia production was observed in seven strains each. Thus, the present investigation revealed that these strains could be used as potential plant growth promoters in sustainable agriculture systems besides putative biocontrol agents.