This ppt is a part of the online lecture for the undergraduate botany students of Government First Grade College Yelahanka , Bangalore by Dr P B Mallikharjuna
1. Page | 1
PLANT INTRODUCTION
Plant introduction is one of the oldest and very basic method of plant breeding.
Plant introduction involves “taking a genotype or a group of genotypes into a
new place or environment where they were not grown previously”.
It means that the growing of a new variety, new species or a new genus that
received from other region /locality /country /continent in a particular area is Plant
Introduction.
1. These species may be a wild relative(s).
2. These species may be a new variety of the species.
3. These species may be a new species altogether.
The process of plant introduction dates back time immemorial and it is still a
continuous process.
The introduced species, varieties, genera are usually called “Exotic” species.
Some of these were un-intentionally introduced especially weeds like Parthenium
are called Invasive species (Harmful).
Several cultivated crops are introduced into India from the different parts of the
globe especially “the centres of origin of crop species”.(Vavilov,1960)
The agents of introduction are plenty in the beginning. They were travellers,
invaders, explorers, naturalists, pilgrims, traders, and even animals too
especially migratory birds etc.
Most of the introductions occurred very early in the history. For instance,
2. Page | 2
a) Muslim Invaders introduced cherries and grapes from Afghanistan into
India.
b) Portuguese introduced maize, groundnut, chillies, potato, sweet potato,
guava, pineapple, papaya and cashew nut into India from different parts of
the world, and
c) The British East India Company brought tea from China.
Later, the Botanic Gardens like NBG (Calcutta) and KBG (Kew) have involved in
the plant introduction process.
Now, there is an agency at national level called NBPGR (National Bureau of Plant
Genetic Resources), and IBPGR (International Board of Plant Genetic Resources,
Rome, Italy) at International level to look after plant introduction.
NBPGR is located in the IARI, New Delhi and established in 1976. Further, it has
five regional centres at Simla (HP), Jodhpur (Rajasthan), Kanyakumar (TN), Akola
( MH) and Shillong (Meghalaya)
The Bureau is responsible for introduction, maintenance and distribution of
germplasm of agricultural and horticultural plants.
Besides this, some other agencies also look after the introduction such as Forest
Research Institute; Dehradun looks after introduction, maintenance and testing
of germplasm of forest trees.
Three processes in the crop improvement programme will take place in a
sequential manner, 1. The process of domestication, 2. The process of
introduction and, 3. The process of acclimatization.
1. Domestication is the process of transforming the wild species into
cultivars/hybrid species through a process of selection and/or
hybridization.
2. Acclimatization is the ability of crop variety to become adapted to new
climatic and edaphic conditions.
3. There are two types of Introduction viz., a) Primary Introduction and b)
Secondary Introduction.
a) Primary Introduction:
When the introduced crop or variety is well suited to the new environment,
it is directly grown or cultivated without any alteration in the original
genotype. This is Primary Introduction.
Ex: IR 8, IR 20, IR 50 Rice varieties
3. Page | 3
Mashuri Rice from Malaysia
Palm oil varieties are introduced from Malaysia.
b) Secondary Introduction:
The introduced variety may subjected to selection to isolate a superior
variety or it may be used in hybridization programme to transfer some
useful traits. This is Secondary Introduction.
Ex: In Soybean, EC39821 introduced from Taiwan is subjected
to selection and variety Co1 was developed.
Objectives of Plant Introduction:
To introduce new species and thereby creating ways to build up new industries.
Ex: Oil Palm
To introduce high yielding varieties to increase food production.
Ex: Rice and Wheat
To enrich germplasm collection. Ex: Jowar and Groundnut
To get new sources of resistance against biotic and abiotic stresses.
Procedure of Plant Introduction:
The main function of plant introduction is to make available variation to be utilized in
breeding programmes. It consists of the following steps:
1. Procurement of plant material:
Receiving the material from a different country directly or indirectly (through
IBPGR) by the NBGPR, India for its direct usage or further breeding programmes.
2. Quarantine:
The received material is subject to inspection, treatment and validation by the
agencies of NBPGR.
3. Cataloguing:
After Quarantine, the particulars of the introduced variety is recorded and after
quarantine, its detailed report is maintained as a Catalogue.
4. Evaluation:
The received, quarantined plant material is further subjected to testing for its
efficacy and quality evaluation in the regional centres of NBPGR.
5. Multiplication and Distribution:
4. Page | 4
The evaluated and promising introduced crop variety is grown in the field and
thereby, released to the farmers for sowing purpose.
Plant Quarantine Method:
1. Plant Quarantine is the most important step in the Plant Introduction
programme.
2. “Quarantine” literally means, “to keep the introduced material in isolation”.
3. The process of Quarantine involves the inspection, treatment and testing of the
introduced plant material (germplasm) at a specific locality under the supervision
of NBPGR.
4. A stringent procedure must adopted in Quarantine process in order to prevent
the entry of weeds, pests and pathogens. Otherwise, the plant introduction will
be more harmful than beneficial. Some of the weeds and pests have entered into
India such as Parthenium, Prosopis and Lantana (Weeds).
Quarantine Rules:
Usually, during quarantine, the introduced material is kept in the isolation for
40 days to prevent the spread of diseases at its entry place.
Sometimes, the received material is screened and subjected to pesticide
treatment within a few hours, and then sent to the addressee.
Whereas, in some other cases, the introduced material is grown in isolation
and kept under observation for diseases, pests and weeds.
The agricultural scientists in the Plant Quarantine are involved under the
supervision of NBPGR. It is also done by the Mycology and Plant Pathology
Dept. IARI, New Delhi on the request of NBPGR.
The Quarantine procedure is carried out under the supervision of NBPGR at
the received ports such as Delhi, Calcutta, Bombay, Chennai etc.
The process of Quarantine involves:
a) Inspection: It will be checked by going through the Phytosanitory Certificate
issued by the sent country. Further, the material would be physically
examined for the good condition and for the weeds/pests/pathogen by
adopting standard procedures.
b) The material is, further subjected to either fumigation or pesticidal or
weedicide treatment to arrest the growth of pathogens/weeds/pests.
c) All the performed activities are maintained as catalogue/records.
5. Page | 5
d) In addition, issues authorized phytosanitory certificate and then sent to the
addressee.
e) If the introduced material does not meet the quarantine rules, it will be sent
back or destroyed by the NBPGR.
GERMPLASM MAINTENANCE:
Germplasm: Is the sum-total of hereditary material or genes present in a species.
Germplasm collection: Collection of a large number of genotypes of a species
and its relatives from all over the world is germplasm collections. There are two
types centres viz., 1. National germplasm collections and 2. World germplasm
collections.
For example, CRRI (Central Rice Research Institute), Cuttack, Orissa is a
World Rice germplasm collection centre with about 15,000 collections.
IRRI – International Rice Research Institute, Manila, Philippines, is also
World germplasm collection with about 22,000 collections.
Sugarcane Research Institute, Coimbatore, is a World Sugarcane
germplasm collection centre with ~2,800 entries.
Both IBPGR (at International level) and NBPGR (in India) will look after the
procurement and maintenance of germplasm collections.
Germplasm collections furnish the richest source of variability, which is a
prerequisite for the breeding programmes.
Maintenance of Germplasm:
There are two types of Germplasm maintenance / conservation in practice viz.,
1. In situ Conservation
2. Ex situ Conservation
1. In situ Conservation is the onsite maintenance of a plant species or
growing/conserving in their original habitats. Some of the in-situ conservations
are Gene Sanctuaries, allowing them to grow in their original habitat. These are
less expensive and involves little labour. Further, it allows the process of natural
selection, which brings more genetic variability.
2. Ex situ Conservation is the off-site maintenance especially other than its original
habitat. It is of two types viz., A) In vivo conservation and B) In vitro conservation.
A) in vivo Conservation shall carried out in greenhouses, fields, plots and
nurseries.
B) in vitro Conservation is the more effective and widely adopted method of
germplasm maintenance. Because it requires the less time and space, and
several germplasms can be maintained. In this type, the germplasm would
6. Page | 6
be stored in the form of seeds, bulbs, tubers, roots, buds, corns, cuttings
etc.
In in vitro conservation, plant tissue culture being used as an effective method of
germplasm conservation.
The methodology of this process includes the low temperature strategies such
as 1.) Cryopreservation and 2.) Cold Storage.
Cryopreservation is a technique, where the germplasm/seed is subjected to solid
Carbon dioxide (-79 ℃) along with some cryoprotectants (DMSO) and stored in
the deep freezers (-80℃)/ freezers of vapour nitrogen (-150℃) or the liquid
nitrogen (-196℃) in order to maintain their longevity.
Cold storage is another technique where the material is preserved under 1-9oC
temperature for short a short period
…………….
POLLEN BANK : is the in vitro preservation of pollen of the important, rare and
endangered plant species under low temperatures (-196
O
C ) for further use. They
are viable and can be used for research activites.
Gene Bank: The collection and its ex situ conservation of germplasm both under
in vivo and in vitro methods for further use is called Gene Bank
Note: Dr P B Mallikharjuna, Associate Professor and Head, Government First Grade
College, Yelahanka prepared this document as a part of online classes on 30th
April and 1st May 2020
References : 1. BD Singh : Plant Breeding
2. JR Sharma : Plant Breeding
3. RS Shukla & PS Chandel: Cytogenetics & Plant Breeding
4. S Bhatia et al: Modern Applications of Plant Biotechnology