Establishment of an efficient callus induction method from leaf and stem in kinnow mandarin (<i>Citrus reticulata Blanco</i>.) and citron (<i>Citrus medica L.</i>)

Abstract

Kinnow mandarin (Citrus reticulata Blanco.) is a highly adaptable variety among citrus cultivars in the climate of the region of Panjab, Pakistan and citron (Citrus medica L.) was the first of the citrus fruits known to become visible in the Mediterranean Basin. In Sylhet region of Bangladesh, it is commonly known as Zara lemon. The establishment of in vitro technique for seed germination and callus induction has been done for kinnow and citron in this experiment. In case of seed germination, ½ MS media supplemented with 6-benzylaminopurine (BAP) (0.5 mg/L)+ 1-naphthaleneacetic acid (NAA) (2.0 mg/L)+KIN (1.0 mg/L) shows best seed germination response (90%) for kinnow and BAP (1.0 mg/L)+NAA (0.5 mg/L) shows best (92%) for citron. For callus induction, 5 weeks old plantlets were used as a source of leaf and stem explants for both. For callus induction from leaf and stem of kinnow mandarin, 2,4-D (1.0 mg/L) shows best result (90%) for leaf while 2,4-dichlorophenoxyacetic acid (2,4-D) (1.0 mg/L)+BAP (0.5 mg/L)+NAA (0.25 mg/L) shows best callus response (95%) for stem explants. In case of citron, 2,4-D (1.0 mg/L) shows best callus response (80%) for both leaf and stem explants.

 Key words:  In vitro, kinnow mandarin, citron, seed germination, callus induction.