CoGent Network

FAQ

Variety, Cultivar, Population and Accession?

 

              old plate coco
 

Figure 1.
Cocos nucifera as pictured in the book
“The Natural History of Barbados”
by Ehret & Hughes, London, 1750.
This type of tall palm is easily recognizable by specialists. It proves to be typical from the varieties of the region: quite thin stem (trunk) curved at the base and elongated fruits. In comparison, most of Tall varieties from Asia have a thicker stem widening at its base and rounder fruits
.

   
   spicata
 

 Figure 2.
Variant for inflorescences:
o
n top, the variant Spicata photographed on a Red Dwarf in the Genebank of the Coconut Industry Board, Jamaica.
On the bottom, normal inflorescence from the cultivar
Malayan Red Dwarf photographed in the International Genebank for Africa and Indian Ocean, Côte d'Ivoire.

   















Variety

The botanical name of the coconut palm is Cocos nucifera Linn. This name designates the only species from the genus cocos of the Arecaceae (Palm) family. In the botanical nomenclature, a “variety” sensus stricto is a taxonomic rank below that of species. At the sub-species level, the botanical nomenclature of the coconut palm will need to be refined in order to integrate the recent advances in science, and especially molecular biology.

Anyway, in the common sense, a variety can be defined as a group of individuals or plants having similar traits that can be reproduced "true to type" from generation to generation. The term variety also applies for coconut hybrids and from any kind of crosses created by breeders for farmers.

Cultivar

The name “Cultivar” comes from a combination of words: Cultivated and Variety. It has the same meaning than “Variety” in the common sense, except that it designates specifically plants selected by mankind.

A cultivar is an assemblage of plant that (a) have been selected for a particular character or a combination of characters; (b) is distinct, uniform and stable in these characters and (c) when propagated with appropriate means, retains those characters.

In 2012, all the coconut varieties conserved by COGENT countries members can be called Cultivars. Almost all the coconut palms are selected and planted by mankind. Even coconuts palms growing naturally along the beaches mostly come from coconut previously selected by mankind. Very few wild coconut palms are remaining except - may be - in the Cocos (Keeling) Islands of the Indian Ocean and along the Northern Coast of Australia. These varieties are not yet conserved in COGENT genebanks.

The experience shows that most non-scientific observers and stakeholders do not know or do not appreciate the term “Cultivar”. They much more frequently use the term “variety” instead of “Cultivar”. Even in many scientific papers, “variety” remains used. So let’s say that the terms of “cultivar” and “variety” are mostly synonyms.

Population and variant

Indeed, these terms have a special meaning for the actual coconut nomenclature. Population and variant refer to a group of individuals obtained from a cultivar. Population designate any subgroup located in a restricted location. Variant could be preferred for special morphological types which may be found in different cultivars; for example it exist a special shape of the inflorescence called Spicata, where the number of spikelets and male flowers are much reduced. This variant can be encountered in many cultivars originating from countries as distant as Philippines, India, and Samoa.

 
For practical example of naming coconut palms, see the FAQ: How an international name is given to a new coconut variety?

Accession

Accession refers to the basic working unit of conservation in the genebanks. For instance, in the case of the coconut palm:

  • The accession numbered ‘SMD NJM R2’ designates a set of 221 coconut palms from the cultivar “Malayan Yellow Dwarf «planted in 1981 on the field number 132 at the Marc Delorme Research Station in Côte d’Ivoire.
  • The accession numbered ‘IND044” designates the only 9 coconut palms from the cultivar East African Tall population Gujarat planted in 1960 at the Central Plantation Crop Research Institute in Kerala, India.

The accession number must be unique. A complete list of coconut accessions conserved in the genebanks of COGENT countries members was made available in 2012 in the framework of a project funded by the Global Crop Diversity Trust and leaded by Bioversity International.

The term accession is widely used. It is also used by molecular biologists when studying and conserving DNA of the coconut palm. In this case, the DNA of each palm is conserving separately; what is called “accession” in DNA genebank is generally the DNA of one palm only. An example of such accessions can be seen on the TROPGEN Database managed by CIRAD.

Ecotype

The term “ecotype” designates individual plants or populations which survive as a distinct group through environmental selection and isolation. It seems to be difficult to qualify most of coconut cultivars as true “ecotype”, so this term is scarcely used by coconut researchers. Some possible exceptions are cultivars found in atolls and other environmentally specific conditions. Vanuatu Tall, for instance, is the only cultivar resistant to the Foliar Decay virus that kills coconuts only in Vanuatu; so Vanuatu Tall can be considered as a true ecotype.

This text was inspired from the work of a COGENT task force wich was constituted in 1999 by Drs Roland Bourdeix, Gerry Santos, Jean Pierre Labouisse and Luc Baudouin. The text was then updated in 2012 to fit with the FAQ format by Dr Roland Bourdeix and Dorine Martinez. For those who want more complete scientific information about names of the plants, please refer to the International Code of Nomenclature for Cultivated Plants and to the  International Code of Nomenclature for algae, fungi, and plant.

 

The Coconut Genetic Resources Network (COGENT) aims to promote national, regional and global collaboration among coconut-producing countries and
partner institutions in the conservation and use of coconut genetic resources for enhanced livelihoods.

The COGENT website is maintained by Bioversity International - Montpellier office.

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