How tissue culture is used to conserve rare and endangered plants?

Answer 1

TISSUE CULTURE-

Introduction

Plant tissue culture is the culture and maintenance of plant cells or organs in sterile, nutritionally and environmentally supportive conditions (in vitro). Plant cell and tissue culture include the cultural techniques for regeneration of functional plants from embryonic tissues, tissue fragments, calli, isolated cells, or protoplasts. It has applications in research and commerce. In commercial settings, tissue culture is often referred to as micro-propagation, which is in fact one of the techniques in tissue culture. Micro-propagation refers to the production of whole plants from cell cultures derived from explants (the initial piece of tissue put into culture) or meristem cells.

The success for plant tissue culture is based on the principle called totipotency - the ability of undifferentiated plant tissues to differentiate into functional plants when cultured in vitro.

Plant tissue culture is used widely in plant science; it also has a number of commercial applications. Applications include:

Micro-propagation is widely used in forestry and in floriculture. Micro-propagation can also be used to conserve rare or endangered plant species.

Micropropagation and cryopreservation are tools with multiple applications and benefits

within an integrated plant conservation research program. CREW's Endangered Plant

Propagation Program has adapted and applied these methods to a broad range of

endangered U.S. species, in collaboration with a number of U.S. botanical gardens within

the Center for Plant Conservation network. In vitro methods are developed for species

for which traditional methods of propagation are not adequate. In addition to standard

tissue culture propagation, techniques for in vitro germination and in vitro collecting can

be used to initiate shoot forming cultures, while in vitro rooting may overcome specific

problems encountered with traditional rooting methods. Micropropagation can also

alleviate stress on the in situ population by providing plants for lab/greenhouse research,

education, reintroduction, augmentation or the establishment of new populations for field

research. Horticultural expertise is important for the successful acclimation of

micropropagated plants for these uses. Cryopreservation banking for long-term

germplasm storage can be applied to a variety of propagules, including seeds, embryos,

spores, pollen, gametophytes, shoot tips, and embryogenic callus cultures. No one

technique will be applicable to every endangered plant, and examples of all of these are

in CREW's liquid nitrogen storage facility, or 'Frozen Garden'. In addition to long-term

storage of rare germplasm, cryopreservation can also help overcome specific problems:

species with seeds or embryos that are short-lived or which have recalcitrant seeds;

species that are not producing many viable seeds; species for which in vitro propagation

protocols have been developed, but for which no habitat is presently suited for

reintroduction. Each species presents a unique opportunity to draw from the variety of

micropropagation and cryopreservation methods in order to develop techniques to

address its specific conservation challenges.