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NISCAIR ONLINE PERIODICALS REPOSITORY (NOPR) >
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Research Journals >
Indian Journal of Biotechnology (IJBT) >
IJBT Vol.03 [2004] >
IJBT Vol.03(2) [April 2004] >
| Title: | In vitro germplasm preservation through regenerative excised root culture for conservation of phytodiversity |
| Authors: | Chaturvedi, H C
Sharma, M
Sharma, A K
Jain, M
Agha, B Q
Gupta, P |
| Keywords: | Caulogenesis
conservation
embryogenesis
excised root culture
germplasm preservation
phytodiversity
regenerants from pericycle
root-regenerated plants |
| Issue Date: | Apr-2004 |
| Publisher: | CSIR |
| IPC Code: | Int. Cl.7 A01 H 4/00, 5/00 |
| Abstract: | In vitro preservation of germplasm becomes imperative for those
plant species in which application of conventional methods is infructuous. Of
the 4 methods of in vitro preservation
of germplasm, viz., cryopreservation, slow growth shoot culture, normal growth
culture and regenerative excised root culture, the last method has some
advantages over the others in case of certain plant species, particularly the
palms. Its main advantages are: Practicability and low cost because of no requirement
of agar-agar, of light as well as of strict maintenance of temperature besides
easy exchange of germplasm across the International boundaries without damage
in transit. However, all these 4 methods have certain shortcomings, which necessitate
adoption of a composite approach involving all of them to achieve the main goal
of conservation of phytodiversity. In general, durations of germplasm
preservation in vitro through
cryopreservation and slow growth shoot culture have ranged from a few weeks to
about 2 yrs depending on the plant species concerned. In certain plant species,
the normal growth culture had afforded germplasm preservation for considerably
long periods of time, viz., more than 27 yrs in Dioscorea floribunda and D.
deltoidea and 32 yrs in Citrus grandis,
albeit with a danger of cultures getting infected during frequent subcultures.
In contrast, the duration of germplasm preservation through regenerative
excised root culture ranged from 6 to 24 yrs. The method of regenerative
excised root culture had been demonstrated to preserve germplasm of a number of
plant species, including herbaceous annuals and perennials and trees, viz., Solanum khasianum (spiny and spineless),
S. torvum, S. surattense, Atropa
belladonna, Kalanchöe fedtschenkoi, Rauvolfia serpentina, Populus deltoides
and Dalbergia latifolia. A similar
possibility existed in case of Shorea
robusta, Cocos nucifera and Elaeis
guineensis, roots of which though established in long-term culture, the
regenerant differentiation in their explants was most sporadic. For
establishing excised root cultures of different plant species, modifications of
various nutrient media, viz., Murashige and Skoog (1962), Street (1954), Street
and McGregor (1952) and White (1943) were used in liquid state, while for
inducing regenerant differentiation, some other modifications of the same media
except of White as well as of Schenk and Hildebrandt (1972) medium were
employed, using different cytokinins, viz., BAP, 2iP, Z and TDZ with auxins,
viz., IAA, NAA and 2, 4-D and also certain growth inhibitors/retardants, viz.,
ABA, CCC and ancymidol as also a polyamine, putrescine. In all cases, agarified
media were used except in R. serpentina, which
required the liquid state of medium for regenerant differentiation, while in S. khasianum and A. belladonna, caulogenesis took place in agarified morphogenic
medium and embryogenesis in the liquid state of medium. Further, whilst in R. serpentina and A. belladonna plantlets were produced via embryogenesis, in rest of
the plant species through caulogenesis. Plants regenerated through long-term
excised root culture were true-to-type, which was substantiated by tracing
their origin from the pericycle tissue of root explants. The root-regenerated
plants fared well under field conditions save A. belladonna, plants of which could be grown in potted soil only
in controlled physical
conditions. |
| Page(s): | 305-315 |
| ISSN: | 0975-0967 (Online); 0972-5849 (Print) |
| Source: | IJBT Vol.03(2) [April 2004]
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