World Journal of Agricultural Sciences 11 (3): 174-182, 2015
ISSN 1817-3047
© IDOSI Publications, 2015
DOI: 10.5829/idosi.wjas.2015.11.3.1854
Corresponding Author: S.C. Chukwu, Department of Crop Production and Landscape Management,
Ebonyi State University, Abakaliki, Nigeria.
174
Characterization of Maize Germplasm Collections Using Cluster Analysis
S.C. Chukwu, E.O. Okporie, G.C. Onyishi and I.U. Obi
1 1 2 3
Department of Crop Production and Landscape Management, Ebonyi State University, Abakaliki, Nigeria
1
Department of Crop Science and Technology, Federal University of Technology, Owerri, Nigeria
2
Department of Crop Science, University of Nigeria, Nsukka, Nigeria
3
Abstract: Conscious expedition was carried out to different parts of Nigeria to collect maize genotypes with
wide variability. The genotypes were coded Gt1 to Gt71 and were first planted in ear-to-row progeny fashion
according to their numbers on May 18, 2013 on a well pulverized flat plot.In order to have a well-organized and
streamlined maize research program, it became important that these genotypes be characterized according to
similarities in traits. Thus, the genotypes were subjected to cluster analysis (CA); a tool which has the
ability to analyze large amounts of genetic information and grouping genes that have similar functions.
The dendrogram constructed classified the 71 genotypes into eight clusters at 5.0 squared Euclidean distance
based on agronomic and chemical characteristics. Clusters VII and VIII had tall and high yielding plants with
low to medium protein, medium to high oil, low to medium amylose and also medium amylopectin, although late
maturing. Clusters V and VI were early maturing but had low yielding and short plants, low protein, high oil,
high amylose and low amylopectin.Clusters I and II were characterized by early maturing genotypes and also
high yielding. Result obtained from second year planting season of 2014 re-affirmed the agronomic
characteristics of these clusters. The 71 maize genotypes, with the help of cluster analysis, were successfully
characterized and accurately grouped into eight clusters with distinct promising features. This is useful for
further maize improvement researches. Clusters VII & VIII and V & VI were recommended for use in recurrent
selection while clusters I & II were recommended for developing inbred lines.
Key words: Cluster Zea mays Germplasm Collection Characterization
INTRODUCTION floury or flint dent.Although maize is increasingly being
Germplasm collection is very much a part of maize food for millions of Nigerians [4].
improvement activities in Nigeria [1]. A systematic luster analysis (CA) is a major technique for
collection and evaluation of locally available maize classifying a ‘mountain’ of information into manageable
germplasm was initiated in 1953. Staton [2] grew all the meaningful piles [5]. It is a data reduction tool that
collected germplasm at Moor Plantation, Ibadan and creates subgroups that are more manageable than
suggested a maize type distribution on the basis of bran individual datum. Like factor analysis, it examines the full
characteristics only.Alika and Aken’ova [3] embarked on complement of inter-relationships between variables.
a systematic collection of local maize in the then Bendel Unlike factor analysis, cluster analysis requires no prior
State to determine the degree of genetic relationship knowledge about which elements belong to which
among the different types and investigate the existence of clusters. The grouping or clusters are defined through an
valuable agronomic traits that could make them sources of analysis of the data. Subsequent multi-variate analyses
useful genes. An interesting observation made was that can be performed on the clusters as groups [6, 7].
the different color types tended to exist in specific areas Clustering occurs in almost every aspect of daily life.
of the state – creamy yellow accessions were found in the According to Banerjee et al. [8], CA provides no
South, while the white was found in the middle to the explanation as to why the clusters neither exist nor is any
more northerly derived Savanna regions. All the yellow interpretation made. Each cluster thus describes, in terms
types were flint while the white types were either flint, of the data collected, the class to which its members
utilized for livestock feed, it is still a very important staple