Essentially Derived varieties In Plant Breeding

EDVs stands for Essentially Derived Varieties, a legal and technical concept in plant breeding and plant variety rights. EDVs are new plant varieties that are predominantly derived from an initial variety but differ in one or more essential characteristics, often through genetic mutation, selection, or other breeding methods. The concept is used to regulate and protect breeders' rights by recognizing varieties that are essentially derived from a protected initial variety, ensuring that the original breeder's rights extend to such new varieties as well. Registration and recognition of EDVs follow specific legal provisions, for instance, under the Community Plant Variety Rights system, with requirements such as demonstrating the derivation from the initial variety, distinctness, and a suitable denomination for the EDV. EDVs that are not protected themselves or for which no application is pending can also be registered in the CPVO (Community Plant Variety Office) register under certain conditions.

1. EDV’s: Essentially derived variety
Def : "essentially derived variety" (EDV) is a plant variety that is
predominantly derived from an initial protected variety, while retaining most
of its essential characteristics and incorporating at least one distinguishable
trait. It essentially means a new plant variety that is created using a
protected initial variety as the primary source. 
Derivation of EDVs:
There are various methods through which EDVs can be derived, including:
(i) mutation, either natural or induced;
(ii) somacolonal variation;
(iii) conventional backcross breeding;
(iv) molecular marker-assisted selection (MAS) during backcrossing; and
(v) genetic transformation.
1. Mutations:
The occurrence and utilization of mutants (both spontaneous and induced) is common
among many plant species, especially the ornamental crops. Inducing mutations in the initial
variety using chemicals or radiation to develop new traits while retaining the original
characteristics.
2. Somaclonal variation:
Somaclonal variation is the genetic variability present among the plants derived from cultured
cells. Some of the prominent examples of somaclonal variants utilized in India, are ‘Pusa
Jaikisan’ which is a somaclonal variant of Brassica juncea variety Varuna, and ‘Ratan’, a
somaclone of Lathyrus sativus (Khesar) with a low neurotoxin (BOAA). Both these varieties
have been released for commercial cultivation.
3.Conventional Breeding:
Backcrossing is the most conservative breeding method as it improves current cultivars only
at few genes at a time. This method has been mostly used for transfer of simply inherited
characters such as disease resistance, which may be governed by oligogenes, or characters
which are monogenic with high heritability.

2. Backcrossing can lead to ‘essential derivation’ as the derived variety is usually highly similar
to the recurrent parent, except for specific trait(s).
4. Molecular marker aided backcrossing:
Marker-assisted selection (MAS) utilizes molecular markers for selection of plants carrying
genomic regions which are involved in the trait of interest. This method can be successfully
utilized for both quantitative and qualitative traits.
Molecular markers can be effectively used for selection in backcrossing in three ways:
(i)If phenotype of the target gene is difficult to observe or highly influenced by
environmental effects;
(ii)Selection of rare progeny with minimum amount of donor parent germplasm or
maximum recovery of recurrent parent genome; and
(iii)Identification of genetic similarity between the progeny with the recurrent parent.
5.Transgenic technology:
▪Genetic transformation employs transferring of specific gene(s) from one organism to
another organism using recombinant DNA technology. The gene used for transformation is
called as a ‘transgene’that confers a particular characteristic, such as insect-pest resistance,
disease resistance, herbicide resistance, quality improvement etc.
Assessment of Essential Derivation:
A variety is clearly distinguishable from all varieties, which are a matter of common
knowledge. Requirements:
➢Conformity to the initial variety in the expression of the essential characteristics.
➢Predominant derivation from the initial variety.
➢Phenotypic characteristics.
➢Breeding records. They are two aspects of essentially derived:
i)The technical aspect
➢Clear distinctness in the sense of the UPOV convention.
➢Conformity to the initial variety in the expression of the essential characteristics.
➢Predominant derivation from an initial variety(IV).
ii)The legal aspect
➢The initial variety must be a protected one.
➢Dependance can exist for protected variety alone.
➢The Variety must not be itself an essentially derived variety.
Registration of an EDV: The Indian Perspective:

3. With respect to EDV, the Act clearly mentions the following:
On receipt of an application, the Authority shall get examined such EDV to determine as to
whether the EDV is a variety derived from the initial variety by conducting such tests and
following such procedures as may as prescribed.
The rights of breeder of an initial variety shall apply to the breeder of EDV.
The authorization by the breeder of the initial variety to the breeder of the EDV is a must,
for entertaining an application for registration of an EDV.

4. If Initial Variety is protected:
If initial variety is not protected:
Protocols for determining EDVs:
Determine the genetic conformity between initial variety and putative essentially
derived variety.
Determine the distinctiveness, uniformity and stability (DUS) of the EDVs.

5. Expression of characteristics that result from the genotypes or combination of
genotypes.
Important information required is genotypic information and genetic distance (GD).
The breeders should maintain the details of pedigree information across years and
seasons.
Genetic distance:
It is important to recognize the fact that the concept of essential derivation is based on
genotype, rather than solely on phenotype; hence, the genetic distance (GD) is required to
be estimated.
The most important and crucial aspect in determination of EDV is the accuracy and
reproducibility of genetic distance. ‘Genetic distance’ can be defined as that difference
between two entities (i.e., plant varieties) that can be described by allelic variation
(Nei,1973).
Molecular markers for EDV determination:
Molecular markers are regarded as suitable tools to distinguish an EDV from an initial
variety as these markers allow tracing of chromosomal segments from the parent to their
progeny and empirical evaluation of genetic relatedness. Molecular markers proved to be
important tools for identification of EDVs in crops like maize (Heckenberger et al., 2002,
2003).
AFLPs, SSRs and RFLPs (Powell et al., 1996) and more recently, SNPs (Single
Nucleotide Polymorphisms) have been successfully used for identification of EDVs in
various crops.