Numerical Taxonomy of South Indian Piper L. II. Principal Component Analysis of the major taxa

Abstract

A principal component analysis study was carried out on the major Piper species occuring in South India, using 17 OTUs and 30 characters. Seven PCs were extracted by the analysis. The first PC consisting of leaf length, leaf breadth, leaf size index, petiole length, distance from the base to the second pair of ribs, plant type, fruit colour, fruit taste and thrips infestation. The second PC consists of spike length, peduncle length, spike orientation and fruit shape. The third PC consists of leaf length/leaf breadth index, rib number, growth habit, and distribution. The fourth PC consists of bract type. The fifth PC consists of leaf length/spike length index and spike shape. The sixth PC consists of guard cell length, guard cell breadth and leaf texture. The seventh PC consists of spike texture. The PC scores were plotted against the principal components and the nature of divergence of various Piper species could be deduced from these scatter plots. P. nigrum showed closest affinity with P. wightii. The results arc discussed.