%0 Journal Article
%T Prospective Zinc Solubilising Bacteria for Enhanced Nutrient Uptake and Growth Promotion in Maize (Zea mays L.)
%A Praveen Kumar Goteti
%A Leo Daniel Amalraj Emmanuel
%A Suseelendra Desai
%A Mir Hassan Ahmed Shaik
%J International Journal of Microbiology
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/869697
%X Zinc (Zn) is one of the essential micronutrients required for optimum plant growth. Substantial quantity of applied inorganic zinc in soil is converted into unavailable form. Zinc solubilising bacteria are potential alternates for zinc supplement. Among 10 strains screened for Zn solubilisation, P29, P33, and B40 produced 22.0£¿mm clear haloes on solid medium amended with ZnCO3. Similarly, P17 and B40 showed 31.0£¿mm zone in ZnO incorporated medium. P29 and B40 showed significant release of Zn in broth amended with ZnCO3 (17 and 16.8£¿ppm) and ZnO (18 and 17£¿ppm), respectively. The pH of the broth was almost acidic in all the cases ranging from 3.9 to 6.1 in ZnCO3 and from 4.1 to 6.4 in ZnO added medium. Short term pot culture experiment with maize revealed that seed bacterization with P29 @ 10£¿g¡¤kg£¿1 significantly enhanced total dry mass (12.96£¿g) and uptake of N (2.268%), K (2.0%), Mn (60£¿ppm), and Zn (278.8£¿ppm). 1. Introduction Zinc is one of the imperative micronutrients required relatively in small concentrations (5¨C100£¿mg£¿kg£¿1) in tissues for healthy growth and reproduction of plants. Zinc deficiency in plants leads to reduced membrane integrity and synthesis of carbohydrates, auxins, nucleotides, cytochromes, and chlorophyll and develops susceptibility to heat stress [1]. Excessive use of zinc fertilizers also poses problems to humans causing the impaired absorption of iron and copper. It is also known to repress male sexuality [2]. The solubility of Zn is highly dependent upon soil pH and moisture and hence arid and semiarid areas of Indian agroecosystems are often zinc-deficient. In India, maize is grown in a wide range of environments, extending from extreme semiarid to subhumid and humid regions. It is grown in about 8.26£¿Mha with yield being 19.3£¿Mt (Ministry of Agriculture, Government of India). Voluminous literature indicates that Zn concentration in the grain is inherently very low, particularly when grown on Zn-deficient soils. The major reason for the widespread occurrence of Zn deficiency problems in crop plants is attributed to low solubility of Zn in soils rather than a low total amount of Zn [3]. Customary application of inorganic zinc partially caters the plant need as 96¨C99% of applied Zn is converted into different insoluble forms depending upon the soil types and physicochemical reactions within 7 days of application [4]. Microbes are potential alternate that could cater plant zinc requirement by solubilising the complex zinc in soil. Several genera of rhizobacteria belonging to Pseudomonas spp. and Bacillus spp. are reported to
%U http://www.hindawi.com/journals/ijmicro/2013/869697/