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Silicon (Si), the second most abundant element on earth, remains unavailable for plants’ uptake due to its poor solubility. Microbial interventions to convert it in soluble forms are well documented. However, studies on discrimination of Si and P solubilizing microbes due to common estimation method and sharing of solubilisation mechanism are still obscure. A defined differential media, i.e., silicon solubilizing media (NBRISSM) is developed to screen Si solubilizers. NBRISN13 (B. amyloliquefaciens), a Si solubilizer, exhibiting antagonistic property against Rhizoctonia solani, was further validated for disease resistance. The key finding of the work is that NBRISSM is a novel differential media for screening Si solubilizers, distinct from P solubilizers. Dominance of Pseudomonas and Bacillus spp. for the function of Si solubilization was observed during diversity analysis of Si solubilizers isolated from distinct rhizospheres. Sphingobacterium zeae, a different strain other than Pseudomonas and Bacillus sp, is identified as Si solubilizer along with a novel strain of Pseudomonas sp. Role of acidic phosphatase during Si solubilization has been firstly reported in our study in addition to other pH dependent phenomenon. Study also showed the combinatorial effect of feldspar and NBRISN13 on elicited immune response through (i) increased Si uptake, (ii) reduced disease incidences, (iii) modulation of cell wall degrading and antioxidative enzyme activities, and (iv) induced defense responsive gene expression.

The objective of this work was to evaluate the relationship among phenotypic and quality traits in a set of indigenous and exotic accessions of linseed (Linum usitatissimum). The experimental material consisted of 151 accessions of linseed belonging to landraces and cultivars collected from diverse agroecological zones. Five randomly chosen plants of each accession in each replicate were tagged, and data were recorded for the 12 following agronomic traits: days to flowering, days to maturity, plant weight, plant height, tillers per plant, secondary branches per plant, capsules per plant, seeds per capsule, 1,000 seed weight, harvest index, seed yield per plant, and oil content. Capsules per plant, harvest index, and plant weight played a direct and indirect major role on seed yield. High heritability, coupled with high genetic advance for plant weight, secondary branches per plant, capsules per plant, and seed yield per plant, suggests that selection based on these traits can be effective. Regarding per se performance, the following accessions can be exploited for commercial cultivation: Shweta (5.41 g), Gaurav (5.07 g), and EX-3-3 (4.77 g) for seed yield; and Shubhra (45.09%), Mukta (44.94%), Laxmi-27 (45.06%), and Shweta (44.25%) for oil content. The chemical profiling of fatty acids obtained in the present study can provide a platform for the selection of accessions for the genetic improvement of linseed.