<i>In Vitro</i> Study of Callogenesis and Regeneration Potential of Elite Wheat (<i>Triticum aestivum</i> L.) Cultivars

Abstract

The potential for biotechnological applications in crop improvement programs requires identifying genotypes that allow cell/tissue culture with predictable plant regeneration. In the past, many genotypes of wheat ( Triticum aestivum L.) have been examined for potential use in tissue culture studies. The present research work has also been designed to study in vitro callogenesis expression and regeneration potential of wheat cultivars under controlled laboratory conditions. Seeds of four elite commercial high yielding cultivars of wheat namely: NARC-2011, AAS-2011, PAK-2013 and GAL-2013, were collected from the Crop Science Institute National Agricultural Research Center (CSI-NARC) Islamabad, as the source of plant material for in vitro studies. The seeds were surface sterilized in 10% sodium hypochlorite solutions for 10 minutes with continuous shaking under laminar air flow hood. After that seeds were placed on MS (Murashige & Skoog, 1962) based callus induction and regeneration medium with various concentrations of 2, 4-D and BAP in separate test tubes. Maximum callus induction frequency of 90% for Pak-13 and AAS-11, followed by 87% and 83% for Gla-13 and NARC-11, respectively, was recorded at 4 mg/l and 6 mg/l of 2, 4-D. Similarly, maximum regeneration of 90% for AAS-11 and Pak-13, followed by 80% and 87% for NARC-11 and Gla-13 respectively, was recorded on MS basal medium containing 1.5 mg/l of BAP. An increasing trend in regeneration from 0.5 to 1.5 mg/l of BAP was observed but it gradually decreased with increasing concentration of BAP from 1.5 mg/l for all wheat cultivars. The callus formed under light was golden brown, dry nodule and smooth compact and less embryogenic while under dark conditions, it was white to yellowish white, dry nodule and compact and more embryogenic. Best results for callus induction and regeneration were obtained at temperature (24°C ± 1°C) for all wheat cultivars.