Morphological characterization of pummelo germplasm collected from different parts of India

Pummelo is a natural non hybrid mono-embryonic and sub-tropical fruit species with vast morphological variability. Morphological characterization of 46 accessions collected from different parts of India on the basis of 42 phenotypic characters including leaf, fruit and seed characters is presented in the paper. Pair-wise similarity analysis revealed moderate to significant variation in the 46 accessions of pummel accessions. Pairwise similarity among the pummelo accessions ranged from 0.31 to 0.66 with an average of 0.48 based on morphometric data. Maximum similarity (0.66) was observed between accessions number of PS-1 and PS-3. Based on Euclidean distance divided these accessions into five main clusters out of which, Cluster I proved the largest cluster comprising of 14 accessions while cluster II consisted of seven accessions and cluster III with ten accessions. Cluster IV was smallest one with only two accessions, while cluster V consisted of 13 accessions. Principal component analysis based on 42 morphological characters showed significant variation among all the accessions. The least variation was observed in qualitative characters, while the quantitative characters significantly differed. The two dimensional (2-D) plot generated from PCA showed three groups which were found to be more or less similar to the clustering pattern of the UPGMA dendrogram. The PCA identified traits were most significant that were responsible for grouping of certain genotypes into specific cluster and hence, revealed some aspects of interrelation among genotypes that were not discernable by the UPGMA analysis. The analysis gave 36 principal components out of which first ten principal components contributed 69.52% of the total variability. The results derived from this study indicated significant level of variability present within the pummelo group in India, which can be used as important source of genetic diversity and for future breeding programmes.