Genetic divergence of indigenous and exotic mandarin (Citrus reticulata Blanco) accessions based on fruit morphological and physiological traits

Abstract

Studies on genetic diversity based on IPGRI descriptors of 14 indigenous and five exotic mandarin genotypes introduced from different parts of India and USA were conducted. Quantitative data were analyzed using SAS (9.3 version) software and the data were also subjected to UPGMA analysis by using DARwin software. Statistically significant differences were observed in quantitative fruit morphological and physiological traits, whereas less variation was recorded in qualitative fruit traits. The cluster analysis divided mandarin genotypes into four major clusters. All the 19 mandarin genotypes were divided into three major clusters. Cluster-I was further consisted of two sub-clusters, namely, cluster IA and cluster IB. In cluster IA, 13 genotypes (mostly indigenous selections) viz., Nagpur, Nagpur Seedless, N-4, Clone-11, CRS-4, N-43, Khasi, Coorg, Mudhkhed Seedless, Darjeeling, N-51, Nova and N-28 were grouped. In cluster IB, two genotypes, namely, N-38 and Fremont were present. Cluster-II included W. Murcott, N-34 and Kinnow genotypes. However, highly distinct genotype, namely, Daisy was present in cluster-III. It was observed that all the hybrids except Nova were clearly differentiated from the indigenous selections because of their higher heterozygosity level. The genotypes from the different geographical regions were clustered across the sub-groups without clear evidence of separation into sub-groups by regions. The study revealed the existence of diverse accessions in mandarin germplasm in spite of accessions exhibiting similar fruit morphological qualitative characters.