Abstract:
Sorghum (Sorghum bicolor (L.)) ranks fifth among cereals in terms of production and area planted
worldwide. It is well adapted to the range of environmental conditions. This study was performed to
evaluate the morphological diversity of some sorghum germplasm accessions based on qualitative
traits. Twenty six sorghum germplasm accessions including sixteen local and ten foreign accessions
(Italian and French) conserved at the seed gene bank of Plant Genetic Resource Center, Gannoruwa,
Sri Lanka were characterized using morphological descriptors outlined by the International Plant
Genetic Resources Institute (IPGRI). The evaluation of these germplasm accessions was based on 4
binary and 10 multicategorical traits. Cluster analysis was performed using SAS software by
following Ward minimum variance clustering method with the dissimilarity measure of Gower and
Legendre. According to the pseudo-F and pseudo-t2 criteria obtained from the cluster analysis based
on qualitative data, the optimal number of clusters required to represent the genetic diversity among
the studied sorghum germplasm accessions was seven. ‘Cluster I’ comprised of two foreign
accessions with unknown origins. Three Italian and two French accessions were clustered in ‘Cluster
III’ while the remaining three Italian accessions were grouped into ‘Cluster IV’. Sri Lankan
accessions were observed in ‘Cluster II’, ‘Cluster V’, ‘Cluster VI’ and ‘Cluster VII’. Clustering
pattern based on the qualitative traits depicts the geographical origin of the studied accessions. This
can be explained by the fact that qualitative traits are less influenced by the environment. In
principle, qualitative data are expected to provide additional information on hierarchical units.
Observation of a considerably high number of clusters consolidates that principle. This study
reveals sufficient genetic relatedness of studied sorghum germplasm accessions which will
meaningful in the conservation and breeding programs of the crops.
