Presentation on Recurrent Selection

1. COURSE TITLE: PRINCIPLES OF
PLANT BREEDING
COURSE NO: PBG-121(HO)

2. RECURRENT SELECTION
The initial idea of recurrent selection was
independently given by Hayes and Garber
in 1919 and East and Jones in 1920. But
the term recurrent selection was first
coined by Hull in 1945.

3. Definition:
 Recurrent selection is defined as reselection
generation after generation, with intermating
of selected plant to produce the population for
the next cycle of selection. The idea of this
method was to ensure the isolation of superior
inbreds from the population subjected to
recurrent selection. The isolation of an
outstanding inbred line depends on two
factors:
 1) The proportion of superior genotypes
present in the base population from which

4. MAIN FEATURES:
 Application : recurrent selection was originally
developed as a method of breeding of cross
pollinated species . Now it is also used in self
pollinated species.
 Base population: A heterozygous base population is
required to start recurrent selection. In cross
pollinated species, a base population may be either
of the five populations, viz.(a)an open pollinated
variety,(b)a synthetic variety,(c)progeny of
intercrosses among selected inbreds,(d)a double
cross,and (e)a single cross.

5. TYPES OF RECURRENT SELECTION
These are four types of recurrent selection.
1. Simple recurrent selection (SRS).
2. Recurrent selection for general combining
ability (RSGCA) .
3. Recurrent selection for specific combining
ability (RSSCA).
4. Reciprocal recurrent selection (RRS)

6. Simple Recurrent Selection (SRS) :
A type of recurrent selection that does not include tester is
referred as simple recurrent selection. It is also known as
phenotypic recurrent selection.
Procedure of Simple RecurrentSelection:
1) A number of plants with desirable phenotype are selected and self-
pollinated in the 1st year.2) In the second year separate progeny rows are grown from selfed
seed of the selected plants.3) The progenies are inter crossed in all possible
combination by hand.4) Equal amount of seed from each cross is composited to produce the
next generation. This complete the original selection cycle.

8. 5) In the third year, bulked seeds are grown and superior plants are
selected and selfed, like first year.
6) In the fourth year, progeny of selected plants are grown from selfed
seed and intermating is done like first year.
7) The crossed seed is composited in equal quantity for use in the next
cycle of selection. This complete first cycle of simple recurrent selection.
Thus selection cycles may be repeated till the desired improvement is
achieved.
Recurrent Selection for General Combining Ability (GCA):
A form of recurrent selection used to important the
general combining ability of a population for a character
and the heterozygous tester is referred as RSGCA. It is
also known as half sub recur selection.

9. Recurrent Selection for SCA:
It was originally proposed by Hull in 1945, a form
of recurrent selection that is used to improve the
SCA of a population for a character by using
homozygous tester is referred as (RSSCA)
recurrent selection for specific combining ability.
It is also known as half site recurrent selection
with homozygous tester.
Reciprocal Recurrent Selection (RRS):
A form of recurrent selection used to improve both
GCA and SCA of a population for a character using
two heterozygous testers is known as RRS. It is also
known as recurrent reciprocal half sib selection.
Comstock et al in 1949, proposed this method.

11. Merits:
1) Recurrent selection is an efficient breeding method for
increasing the frequency of superior genes for various
economic characters.2) It helps in breaking repulsion phase of
linkage.3) It helps in maintaining high genetic variability due to
repeated intermating of heterozygous population.
Demerits:
1) It is not directly used for the development of new
varieties.
2) This method involves lot of selection crossing and
selfing work.
3) It permits selfing , which leads to loss of genetic
variability.

12. CONCLUSION:
 Recurrent selection is a cyclic selection
that is used to improve the frequency of
desirable alleles for a character in a
breeding population.
 In other words it is an important
method of population improvement.

13. SUBMITTED TO: Dr KAUSHIK PANIGRAHI
SUBMITTED BY: SHUBHRANKSHI
PRIYADARSHINI
ADMISSION NO: 33HO/16