Abstract
Characterisation of germplasm resources is vital for efficient management of breeding programs. Commonly used methods include biochemical, morpho-agronomic, molecular and to some extent cytological characterisation. With an effort to rescuscitate an ailing national sunflower breeding program after a series of major droughts, 16 female (A) lines and 10 male (R) lines were morphologically characterised. Ten morphological variables namely days to 50% flowering, head diameter, leaf length, leaf width, petiole length, nodding, lodging, number of leaves, plant height, stem diameter and uniformity were used for characterisation. Data was collected and analysed using Genstat software. After an ANOVA, principal components analysis (PCA) and hierarchical cluster analysis were used to examine distribution patterns in the germplasm. Significant differences were observed for the variables (p˂0.001). Hierarchical clustering on morphological data indicated an overall similarity index of 91%, that is, 9% dissimilarity was observed. For PCA, it can be observed that the cytoplasmic male sterile (CMS) lines are more spatially distributed as compared to the R-lines. The genetic base of the collection was observed as narrow and would need more diversification otherwise inter-crosses will not produce much gain.
Key words: Morphological variables, compositae family, principal components analysis, cluster analysis.
