PHYTOGEOGRAPHICAL STUDIES IN THE GENUS MORUS L. I. GEOGRAPHICAL DISTRIBUTION AND NATURAL VARIATION OF MORUS SERRATA ROXB

Abstract

Morus L. is an important genus of the family Moraceae and is distributed
in temperature and subtropical regions of both the hemispheres. The genus
is beleived to be originated in the temperate mountain regions of South east
Asia. Vavilov has recognised 'China-Japan' gene centre as the centre of origin
of this genus. Of the 68 species recOgnised from different parts of the world,
38 species are found in Asia and 14 in continental America (Sanjappa, 1989).
The genus is also represented in middle east, Europe, and South Africa. Owing
to the fast spread of sericulture to more than 60 countries in the recent past,
numerous varieties belonging to different species have been introduced to all
these countries. In India, Morus is represented by four species namely M.alba,
M. indica, M. laevigata and M. serrata (Hooker, 1885), which are distributed in
north-west, central and north-east Himalayas. The importance of wild species
in mulberry improvement programmes has been realised in recent years. A
systematic approach to study and collect the mulberry germplasm from
Himalayas was taken on priority by C.S.R. &: T.I., Mysore.