American Journal of Plant Sciences, 2013, 4, 2001-2005
http://dx.doi.org/10.4236/ajps.2013.410249 Published Online October 2013 (http://www.scirp.org/journal/ajps)
2001
In Vitro Plant Regeneration of Morus indica L. cv. V1
Using Leaf Explant
Melur Kodandaram Raghunath
1
, Karaba N. Nataraja
2*
, Jyothi Sainath Meghana
1
,
Radha Sivarajan Sajeevan
2
, Mala V. Rajan
1
, Syed Mashayak Hussaine Qadri
1
1
Central Sericultural Research and Training Institute, Srirampura, Mysore, India;
2
Department of Crop Physiology, University of
Agricultural Sciences, GKVK, Bangalore, India.
Email:
*
nataraja_karaba@yahoo.com
Received March 26
th
, 2013; revised April 27
th
, 2013; accepted May 19
th
, 2013
Copyright © 2013 Melur Kodandaram Raghunath et al. This is an open access article distributed under the Creative Commons Attribu-
tion License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
ABSTRACT
Adventitious bud induction and plantlet regeneration were studied in a popular mulberry variety, V1 using leaf as an
explant. Fully expanded leaf explants were cultured on Murashige and Skoog’s (MS) medium supplemented with thidi-
azuron (TDZ) (0.5 - 4.0 mg/l), 6-benzylaminopurine (BAP) (0.5 - 2.0 mg/l), indole acetic acid (IAA) (2.0 mg/l), gibber-
lic acid (GA
3
) (1.0 - 2.0 mg/l) silver nitrate (AgNO
3
) (2.0 mg/l) and different carbon sources such as sucrose, fructose
and glucose (10% - 30%) either individually or in combination to induce adventitious buds and regeneration. The high-
est percentage (63%) of adventitious bud formation and regeneration (68%) was achieved in the medium containing MS
with TDZ (1.0 mg/l), IAA (2.0 mg/l) and AgNO
3
(2.0 mg/l). For subsequent regeneration and shoot elongation the MS
medium having BAP (1.0 mg/l), GA3 (2.0 mg/l) and AgNO
3
(2.0 mg/l) was found to be suitable. Amongst the carbon
sources tested, the most suitable carbon source was found to be sucrose (3%) followed by fructose (2%) for adventitious
bud formation. Excised in vitro shoots were rooted (60% - 80%) in half strength MS medium supplemented with in-
dole-3-butyric acid (1.0 mg/l). The well rooted plantlets were hardened in soil + sand + farm yard manure (FYM) mix-
ture with a success rate of 70% - 90%. Since in vitro regeneration is highly genotype-dependent in mulberry, the stan-
dardized protocol can be effectively used for further improvement of this leading genotype using biotechnological ap-
proaches.
Keywords: In Vitro Regeneration; Adventitious Bud; Thidiazuron; Mulberry cv. V1; Carbon Source
1. Introduction
Mulberry (Morus spp.) is a woody perennial tree of im-
portance to the sericulture industry as mulberry leaf is the
sole food for the silkworm (Bombyx mori L.) larvae. Ow-
ing to its long juvenile period and heterozygosity [1], im-
provement of specific characters through conventional
breeding is cumbersome and time consuming. Therefore
targeted manipulation of elite genotypes through incor-
poration of specific genes encoding desired traits using
modern biotechnological methods offers a new opportu-
nity for crop improvement. An efficient in vitro regenera-
tion procedure is pre-requisite for transgenic approach in
any crops. Information on development and standardiza-
tion of in vitro regeneration protocols in promising mul-
berry genotypes is limited, although there are reports
in a few genotypes. Studies have been made in mulberry
to examine the impact of various growth regulators on in
vitro organogenesis and plant regeneration by using dif-
ferent explants viz. leaf, internodal segment, hypocotyls
and cotyledons [2-12]. However, the shoot differentiation
from callus is confined only to a few genotypes and re-
peatability of protocols developed was not assured due to
the recalcitrant nature of the plant. In this study, we made
an attempt to develop and standardize in vitro regenera-
tion protocol in a widely cultivated mulberry variety, V1
using leaf explants. The variety is highly popular due to
its economic characters under irrigated conditions and
the foliage is suitable for both young and late age bivol-
tine silkworm rearing. The major emphasis was given to
investigate the effect of Thidiazuron (TDZ), a substituted
phenyl urea and different carbon sources in inducing ad-
ventitious buds and efficient regeneration in V1.
*
Corresponding author.
Copyright © 2013 SciRes. AJPS