Comparison of Mahalanobis's method and metroglyph technique in the study of genetic divergence in Linum usitatissimum L. germ plasm collection

Abstract

A group of fifty-seven varieties of Linum usitatissimum L. collected from different geographics sources was studied to understand the nature of genetic divergence using Mahalanobis's statistical distance (D2). Varieties having genetic similarity were grouped into fifteen clusters. Most of the clusters at individual level included varieties of different geographical regions. However, Argentine and Indian types formed separate and distinct constellations. The Indian group was situated at a maximum distance from Argentine and US groups, and was nearest to the Australian group. For improvement of Indian linseed, hybridization of indigenous types with Argentine and US types might result in superior recombinants. 84.64% of the total divergence was attributable to plant height and seed size, which are based characteristics used in classifying the species into oil and flax types. Since it is difficult to compute D2 values among large numbers of germplasm collections, another relatively simple and easy method, the metroglyph technique, was tried upon the same set of fifty-seven varieties. Comparisons between the results of the two analyses revealed the striking similarity as regards to group arrangement. It has been suggested that the metroglyph technique would be suitable for preliminary grouping prior to undertaking D2 analysis.