Trichoderma is the most commonly used fungal biocontrol agent throughout the world. In the present study, various Trichoderma isolates were isolated from different vegetable fields. In the isolated microflora, the colony edges varied from wavy to smooth. The mycelial forms were predominantly floccose with hyaline color and conidiophores among all the strains were highly branched. Based on morphological attributes, all the isolates were identified as Trichoderma harzianum. The molecular identification using multilocus sequencing ITS, rpb2 and tef1α, genes further confirmed the morphological identification. The average chitinase activity varied from 1.13 units/mL to 3.38 units/mL among the various isolates, which increased linearly with temperature from 15 to 30 °C. There was an amplified production in the chitinase production in the presence of Mg⁺ and Ca²⁺ and Na⁺ metal ions, but the presence of certain ions was found to cause the down-regulated chitinase activity, i.e., Zn²⁺, Hg²⁺, Fe²⁺, Ag⁺ and K⁺. All the chitinase producing Trichoderma isolates inhibited the growth of tested pathogens viz., Dematophora necatrix, Fusarium solani, Fusarium oxysporum and Pythium aphanidermatum at 25% culture-free filtrate concentration under in vitro conditions. Also, under in vivo conditions, the lowest wilt incidence and highest disease control on Fusarium oxysporum was observed in isolate BT4 with mean wilt incidence and disease control of 21% and 48%, respectively. The Trichoderma harzianum identified in this study will be further used in formulation development for the management of diseases under field conditions.

Dar GH, Sofi S, Padder SA, Aisha Kabli A. 2018. Molecular characterization of rhizobacteria isolated from walnut (Juglans regia) rhizosphere in Western Himalayas and assessment of their plant growth promoting activities. Biodiversitas 19: 712-719. The present study was aimed to isolate and characterize effective bacteria from the rhizosphere of walnut (Juglans regia) grown in North Western Himalayas and assess their growth promoting potential so that they may, in future, be exploited as biofertilizers. Based on preliminary screening of 98 bacterial isolates obtained from four walnut growing districts of Kashmir valley during survey in 2015, 12 isolates were characterized morpho-biochemically and molecularly basis. On the basis of 16S rDNA sequencing they were identified as Bacillus licheniformis WI 90, B. tequilensis WI 62, B. cereus WI 36, B. subtilis strains WI 63 and WI 65, Micrococcus luteus strains WI 12, WI 41 and WI 80; M. yunnanensis strains WI 60 and WI 30 and Micrococcus sp. strains WI 11 and WI 91. The assessment of these rhizobacteria for plant growth promoting attributes revealed that B. licheniformis WI 90 possessed higher phosphorus solubilization activity (312 mg/L), followed by Micrococcus sp. WI 91 (267 mg/L) while high siderophore was produced by M. luteus WI 12 (27.2% siderophore units), followed by B. licheniformis WI 90. B. cereus strains WI 36. High IAA contents (30 µg/mL) was yielded by WI 41, followed by M. yunnanensis WI 60 (28 µg IAA/mL) while higher and statistically at par gibberellic acid was produced by B. licheniformis WI 90, Micrococcus sp. WI 91 and M. luteus WI 80. Higher chitinase enzyme activity was observed in B. subtilis WI 63 (30.5 units/mL), followed by B. tequilensis WI 62 (25.3 units/mL) and B. subtilis WI 65 (25.1 units/mL). The study revealed high plant growth promoting potential in these rhizobacteria.

The large genetic evolution due to the sexual reproduction-mediated gene assortments and propensities has made Venturia inaequalis (causing apple scab) unique with respect to its management strategies. The resistance in apple germplasm against the scab, being controlled for by more than fifteen genes, has limited gene alteration-based investigations. Therefore, a biological approach of bacterial endophyte community dynamics was envisioned across the apple germplasm in context to the fungistatic behavior against V. inaequalis. A total of 155 colonies of bacterial endophytes were isolated from various plant parts of the apple, comprising 19 varieties, and after screening for antifungal behavior followed by morphological, ARDRA, and sequence analysis, a total of 71 isolates were selected for this study. The alpha diversity indices were seen to fluctuate greatly among the isolation samples in context to microflora with antifungal behavior. As all the isolates were screened for the presence of various metabolites and some relevant genes that directly or indirectly influence the fungistatic behavior of the isolated microflora, a huge variation among the isolated microflora was observed. The outstanding isolates showing highest percentage growth inhibition of V. inaequalis were exploited to raise a bio-formulation, which was tested against the scab prevalence in eight apple varieties under controlled growth conditions. The formulation at all the concentrations caused considerable reductions in both the disease severity and disease incidence in all the tested apple varieties. Red Delicious being most important cultivar of the northwestern Himalayas was further investigated for its biochemical behavior in formulation and the investigation revealed different levels of enzyme production, chlorophyll, and sugars against the non-inoculated control.

Colchicum luteum L. is an economically important and endangered medicinal plant of the Kashmir Himalaya. The corm extract is used for the treatment of rheumatism, gout, Behcet’s syndrome, and Alzheimer disease. It is also used extensively in plant breeding programs for the doubling of chromosomes. The present study was carried out for two years (2017–2019) to study the genetic diversity of C. luteum, an economically important and endangered medicinal plant of Kashmir Himalaya. The mapping of genetic diversity of C. luteum was estimated using Mahalanobis D² analysis in the Aharbal (Kulgam), Dhara (Theed), and Baera Baal Hills (Harwan) of Kashmir Valley. The results showed the presence of 5 clusters for 30 populations. There were 17 populations in cluster-1, 1 in cluster-2, 2 in cluster-3, 3 in cluster-4, and 7 in cluster-5. The majority of the population was a group in cluster-1 followed by cluster-5. The maximum intracluster distance (D² values) was observed in cluster-5 (46.55588) followed by cluster-3 (41.61871), and the maximum inter-cluster distance (D² values) was observed in cluster-3 (46.55588) followed by cluster-5 (41.61871). Our study revealed that plant species possessed sufficient genetic diversity among the populations. Cluster-5 showed superiority in plant⁻¹ respect of the maximum mean plant height (28.46 cm), leaf area (47.0 cm²), number of seeds plant⁻¹ (26.85), corm length (5.15 cm), corm width (3.17 cm), fresh weight of corm plant (6.87 g), and dry weight of corm plant (4.81 g) as compared to other clusters. Out of five clusters, cluster-5 is a promising one for better yield and yield attributing traits. The present study revealed that plant species possessed sufficient genetic diversity among the populations as 30 populations were arranged into 5 clusters. Therefore, cluster-5, consisting of seven populations from the undisturbed area of Harwan, and consequently the populations from the same cluster can be multiplied for initiating a conservation and breeding program and can serve as a tool for the scientific community to evolve better contemporary varieties of C. luteum with profitable characters such as more yield of corms, etc. This will assist farmers, particularly the marginal farmers, to alleviate their income.