Assessment of phenotypic variability in rice (Oryza sativa L.) cultivars using multivariate analysis

摘要

Sixty-eight commercial and primitive cultivars belonging to aromatic (basmati), non-aromatic (coarse) and japonica type were used during present investigation. A considerable level of polymorphism was observed among aromatic, non-aromatic and japonica cultivars for the majority of the morphological characters measured. Cluster and principal component analyses were used to classify rice cultivars on the basis of phenotypic traits. Dendrogram was generated for the Euclidean distance and phenotypically all the cultivars were classified into three major groups corresponding to the forms of indica rice cultivated in Pakistan, i.e., aromatic (Basmati) and non-aromatic (Non-basmati) with few exceptions. Clustering of the cultivars did not show any pattern of association between the morphological characters and the origin of the cultivars. Instead cultivar groups were associated with their morphological similarities and type of indica rice cultivated in various regions of Pakistan. Regardless of the limitation in estimating total genetic variation, the current study indicated that agro-morphological traits were helpful for preliminary characterization and can be used as a broad-spectrum approach to assess genetic diversity among morphologically distinguishable rice cultivars.