Divergence in Relation to Geographical Origin in a World Collection of Linseed

In the present study, one hundred types of Linutn usitatissimum, drawn at random from the Institute collection and representing seven geographical regions, namely, Afghanistan, Europe, Russia, India, U.S.A. -Canada, Argentina and Australia were examined and the nature of genetic divergence estimated by multivariate analysis using Mahalanobis's D-² statistic.

Based on Mahalanobis's D-² statistic, the present study revealed that the Indian group is distinctly different from the rest of the seven groups. The European material is not very diverse from Russian, American and Australian material. Argentina and Afghanistan groups are close to each other. The maximum diversity is between Indian and Russian groups followed by Indian and European groups. The diversity of Indian material from rest of the world collection confirms that Indian linseed is of polyphyletic origin, which might have been introduced into India by the Aryans from Central Asia, Egypt and Abyssinian sources.

An examination of the contribution of individual characters to the divergence between pairs of varieties showed that the number of primary branches has contributed the maximum to divergence, followed by the level at which fruiting branches start. However, within the European and Russian groups, the level of first fruiting branches made the maximum contribution. These two characters are also potent factors of differentiation of oilseed from flax types. The potency of level of fruiting branches in the diversification in linseed has been recognised only recently, since this would substantially alter the plant type.