Effect of Plant Growth Regulators on Micro-Propagation of Selected Sri Lankan Traditional and Improved Rice Cultivars (Oryza sativa L.)

Abstract

In this study five selected Sri Lankan traditional rice varieties (Kaluheenati, Sulaai, Suwadhal, Dostara Heenati) (Oryza sativa L.) and five improved rice varieties (At362, Bg94/1, Bg358, Bg357, Bg379) were examined for callus induction, plant regeneration and rooting using in vitro techniques. Seeds were cultured in five different hormone concentrations; 1.0, 1.5, 2.0, 2.5, 3.0 mg/l 2, 4- Dichlorophenoxy acitic acid (2, 4-D) and 0.1 mg/l 6 – Benzyl adenine purine (BAP) on Murashige and Skoogs (MS) basal medium for callus induction. Proliferated calli were transferred to five different hormone concentrations; 1.0, 1.5, 2.0, 2.5, 3.0 mg/l BAP with 0.1 mg/l Indole acetic acid (IAA) to regenerate shoots. Regenerated shoots were transferred to three different hormone concentrations; 1.5, 2.0, 3.0 mg/l Indole butric acid (IBA) for rooting. Complete Randomized Design (CRD) was used with ten replicates and data was analyzed by SAS 9.1.3 version. The interaction between plant varieties and different hormone concentrations are highly significant for callus diameter, number of shoots per explants and root length. All tested rice cultivars (100%) were able to produce callus however only 40% of rice varieties were regenerate shoots. The regeneration ability of rice varieties varied from 0% to 100%. All shoots were able to produce 100% roots in tested IBA concentrations. Among all selected rice varieties 2.0 mg/l 2, 4-D+0.1 mg/l BAP is most successful for callus induction while 2.0 mg/l BAP+0.1 mg/l IAA and 2.0 mg/l IBA most effective for shoot regeneration and root induction respectively