Micropropagation of Citrus macroptera Montr. using explants from in vitro generated seedlings

  • Shabaree Y.A. Sangma Department of RDAP, North-Eastern Hill University, Tura Campus, Tura, West Garo Hills, Meghalaya, 794002
  • Lolly S. Pereira Department of RDAP, North-Eastern Hill University, Tura Campus, Tura, West Garo Hills, Meghalaya, 794002
  • J.C. Dang Department of Botany, Don Bosco College, Tura, West Garo Hills, Meghalaya, 794002.
Keywords: Chambil, endangered citrus, in vitro propagation, Garo Hills, Meghalaya, Nokrek Biosphere Reserve

Abstract

Citrus macroptera Montr. known as ‘Chambil’ in Garo language is an endangered species
which grows in wild and semi wild conditions in Meghalaya. It has great significance in the
life of the Garo tribe of Meghalaya for its culinary and medicinal uses, as well as for its use in
traditional rituals. The slow natural regeneration, recalcitrant seeds, lack of commercial
cultivation and clearing of forest area for various developmental activities are a threat to this
species and need attention for conservation. Considering these facts, in vitro trials were
conducted for standardization of protocol for mass multiplication of Citrus macroptera with
five explants from in vitro germinated seedlings. Among the treatments evaluated for nodal
segment, MS medium incorporated with 0.5 mg/l BAP showed highest response of 91.49%
with 6.04 shoots of 2.05 cm length in 6.16 days. Out of the treatments tried with shoot tip,
highest response (66.24%) was observed in MS medium supplemented with BAP 1.0 mg/l
producing 2.08 shoots of 1.04 cm length within 5.75 days. Among the treatments assessed for
cotyledon explants, MS medium with BAP 1.0 mg/l produced the highest number of 3.88
shoots of 2.10 cm length in 19.77 days showing 73.77 % response. With callus initiation rate
of 63.33%, leaf discs cultivated on full strength MS media with 0.5 mg/l of 2, 4-D produced
viable callus in 7.33 days. The highest shoot bud proliferation (73.33%) was seen in this
callus when grown on full strength MS medium with BAP 1.0 mg/l, which produced 11.13
shoots. Root tips of in vitro seedlings did not produce any shoots. The rooting percentage of
in vitro produced Citrus macroptera shoots cultured on full strength MS medium with IBA
1.0 mg/l + NAA 1.0 mg/l was 94.44% with 5.55 roots per shoot of 4.5 cm length in 11.94
days, the highest of the many treatments taken into consideration. Seventy per cent in vitro
rooted plantlets survived in open conditions. Results indicate that protocol developed for in
vitro plantlet regeneration from nodal segments of in vitro raised seedlings, can be used for
mass multiplication of Citrus macroptera .

Published
2022-12-24