Extensive development of canal irrigation system led to formation of unproductive sodic lands, which limited the cultivation of flower crop gladiolus in the basins of major rivers. The purpose of this study was to isolate native rhizospheric and endophytic bacteria from sodic environment and evaluate their growth enhancement and bio-ameloirant properties in gladiolus under sodic soils. Sixteen isolates of plant-growth-promoting rhizospheric and endophytic bacteria were isolated and screened for growth promotion potential. The promising strains were identified and evaluated for growth and production in gladiolus. The plants treated with strains CSR-G-1, CSR-B-2, and CSR-B-3 significantly produced marketable spikes and higher number of florets/spike. Also, the treated plants showed an increased activity of superoxide dismutase, phenyl alanine lyase, catalase, peroxidase, phenols, and proline than control. Further, the soil pH, total carbonates, and sodium adsorption ratio were lower in treated soils. The Na + /K + ratio in leaves of treated plants was observed to be lower than control. In conclusion, these bio-inoculums can be used as growth enhancer and bioameliorant in sodic soils as an eco-friendly management strategy.

Genetic diversity among four wild mango species and 29 genotypes/cultivars of polyembryonic and monoembryonic mangoes of the Andaman Islands were analysed using inter simple sequence repeat (ISSR) markers. A total of 335 ISSR markers were scored, of which 213 markers were polymorphic. These markers were used to estimate the genetic similarity among accessions using a Dice similarity coefficient. Similarity values ranged between 2Á70% with an average of 34%. A similarity matrix was used to construct a dendrogram and principle coordinator plot to show genetic relationships among accessions. The sampled genotypes/accessions were divided into three prominent groups of 4, 16 and 13, differentiating the polyembryonic genotypes from monoembryonic genotypes and wild mango species. The study provides further information on the evolution and diversity of the mango accessions of the island ecosystem. The analysis also separates the differentially flowering polyembryonic genotypes from the early flowering monoembryonic types for their exploitation in genetic improvement programmes or selection in the regions of tropical island ecosystems where the attribute of early flowering can be effectively utilised.

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