Efficacy of various extractants—AB-DTPA, 0.5 m Na2CO3, 0.25 m KCl, 0.1 m KH2PO4, hot water, and isotopically exchangeable selenium (Se)—was studied for estimating bioavailable Se in 15 naturally occurring alkaline seleniferous soils in north-western India. Total Se concentration in these soils varied from 0.6 to 3.1 µg/g. Amount of Se extracted as isotopically exchangeable was the greatest, and that extracted with 0.5 m Na2CO3 was the smallest. When grown in the seleniferous soils, raya (Brassica juncea) accumulated (μg Se/g dry matter) 1.5–86.6, wheat (Triticum aestivum L.) 0.7–58.3, maize (Zea mays L.) 1.7–8.6, and rice (Oryza sativa L.) 1.5–4.6. Raya, wheat, and maize plants absorbed Se more than the maximum permissible level for animal consumption (5 μg Se/g dry matter) in 9, 8, and 4 experimental soils, respectively. Selenium concentration of maize was significantly correlated with the amount of Se extracted by 0.25 m KCl (r = 0.646,P < 0.01), 0.1 m KH2PO4 (r = 0.498,P < 0.10), and with total Se concentration (r = 0.628,P < 0.05) of the soils; Se concentration in rice was correlated with AB-DTPA extractable Se (r = 0.443,P < 0.10). Highly significant relationships between hot water soluble Se and concentration of Se in raya (r = 0.705,P < 0.01), wheat (r = 0.696,P < 0.01), maize (r = 0.698,P < 0.01), and rice (r = 0.559,P < 0.05) suggest that it can reliably quantify bioavailable Se in seleniferous soils of north-western India. Hot water soluble Se was positively correlated with electrical conductivity (r = 0.514,P < 0.05), total Se concentration (r = 0.710,P < 0.01), and KCl-extractable Se (r = 0.712,P < 0.01) of the soils.
Genetic Diversity and Population Structure of Basmati Rice (Oryza sativa L.) Germplasm Collected from North Western Himalayas Using Trait Linked SSR Markers