An Efficient Regeneration System for Native Orange (<i>Citrus reticulata</i>) through <i>In-Vitro</i> Culture Technique

Abstract

Citrus reticulata (Mandarin Orange), commonly known as “Sweet Orange”, is one of the most difficult plants to improve through traditional breeding approaches as it poses various biological limitations that greatly hinder the cultivar improvement. In the present study, using the fresh seed of native orange as explant, an efficient, reproducible, regeneration method was developed through in vitro organogenesis. Mature, healthy and dehusked seeds were treated with Murashige and Skoog, (MS) media containing 3% sucrose, 0.7% agar supplemented with different concentrations and combinations of phytohormones. The highest calli initiation (93.3% ± 0.5%) responses were observed on MS medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) at 3.0 mg/L followed by 2,4-D at 3.5 mg/L (86.7% ± 1.75%) in this experiment. Maximum shoot regeneration (86.7% ± 3.35%) responses were reported using MS medium supplemented with the combination of 6-benzylaminopurine (BAP) at 3.0 mg/L and 1-naphthaleneacetic acid (NAA) at 2.0 mg/L. MS medium supplemented with NAA at 1.0 mg/L showed the best rooting (80% ± 2.89%) response in comparison to (70% ± 5.20%) indole-3-butyric acid (IBA) at 1.0 mg/L. The regenerated plantlets were acclimatized in pots containing sterile garden soil mixture to examine their response in natural conditions.