ESTIMATION OF GENETIC DIVERSITY IN SOME COTTON (GOSSYPIUM HIRSUTUM L) GENOTYPES
ESTIMATION OF GENETIC DIVERSITY IN SOME COTTON (GOSSYPIUM HIRSUTUM L) GENOTYPES
No Thumbnail Available
Date
2015-08
Authors
ABDULLAH, MUHAMMAD IYAD
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Forty nine cotton genotypes were evaluated at Samaru, Northern Guinea Savanna Zone of
Nigeria during 2013 cropping season. The experimental design used was 7×7 lattice design
with three replications. Plant data recorded on twelve characters were subjected to analysis
of variance, Principal component analysis, Cluster analysis, Rank summation index and
Correlation analysis. Analysis of variance revealed highly significant differences (p<0.01)
for days to 50% flowering, fibre length and fibre fineness, while non-significant differences
(P>0.01) were observed in the remaining agronomic traits. The phenotypic coefficients of
variations were higher than the corresponding genotypic coefficients of variations for the
entire traits studied. Seed cotton yield had the highest genotypic coefficient of variation.
The first five axes of principal components analysis having eigen value >1 captured 63.60%
of the total variability and jointly identified number of sympodia, number of bolls, ginning
outturn, seed cotton yield, boll weight, seed index, days to 50% flowering, fiber length, and
lint index as characters contributing most to the total variability. Mean performance
revealed moderate variability in all the means of the agronomic traits studied. The
variability was highest for seed cotton yield, and by plant height. Means of the fiber quality
traits showed considerable variability among the genotypes especially for fiber length, and
fiber fineness. Correlation analysis revealed that days to 50% flowering, plant height,
sympodia per plant, boll weight, seed index, number of bolls and fiber fineness were highly
significant and positively correlated with seed cotton yield, while highly significant
negative correlations are observed between number of monopodia, ginning outturn, and
fiber length with seed cotton yield. From rank summation index genotypes PIMA S4, RSA
(79) 4A, ASA (78) 34A, SAMCOT 12 and SAMCOT 13 are the best genotypes for all the
viii
traits studied. Cluster analysis grouped 49 cotton genotypes into five major clusters with
each cluster having distinct features. The present investigation provided considerable
information useful in genetic improvement of cotton. Genotypes PIMA S4, RSA (79) 4A,
ASA (78) 34A, SAMCOT 12 and SAMCOT 13 obtained from the USA, Mexico and
Nigeria were the best materials for all the traits studied. These genotypes are therefore
considered the best potential parents use in for the hybridization programs for the
improvement of cotton in Nigeria. Important morphological and fiber quality traits like
greater seed cotton yield potential, plant height, fibre length, fibre fineness, number of
sympodia per plant and number of bolls per plant etc. served as selection criterion to
produce promising cotton genotypes. The low level of genetic diversity observed among
the genotypes studied indicate the need for breeders to search for novel and diverse material
in order to explore the unutilized genetic diversity for future cotton breeding program of
Nigeria.
Description
AHMADU BELLO UNIVERSITY, ZARIA IN PARTIAL FULFILMENT OF THE
REQUIREMENTS FOR THE AWARD OF A MASTER DEGREE OF SCIENCE IN
PLANT BREEDING
DEPARTMENT OF PLANT SCIENCE,
FACULTY OF AGRICULTURE
AHMADU BELLO UNIVERSITY, ZARIA
NIGERIA
AUGUST
Keywords
ESTIMATION,, GENETIC,, DIVERSITY,, COTTON,, GOSSYPIUM HIRSUTUM L,, GENOTYPES