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Mulberry which belongs to the genus Morus is an economically
important plant that is used as the sole food for rearing
silkworms. Existing conventional methods of identification
of different cultivars are difficult due to close similarities.
Here we have described the use of polymerase chain reaction-based
Random Amplified Polymorphic DNA (RAPD) for developing cultivar
specific markers that can be employed in the identification
of some popular mulberry cultivars of Karnataka. Twenty-five
decamer oligonucleotide primers were screened for five different
mulberry cultivars, among which three primers scored 47
bands ranging from 500-5000 bp. PCR amplification with these
primers yielded 1-10 bands per primer. Genetic tree was
constructed based on the band score following Ward's method.
In the present study, we have also identified few putative
cultivar specific RAPD markers that could be useful in developing
SCAR markers for further studies in germplasm conservation
and identification of mulberry cultivars.
Mulberry (Morus alba) is an important plant that acts as
the food for the silkworm Bombyx mori L. The genus Morus
belonging to the family Moraceae is widely distributed in
Africa, Europe, Asia, South and North America. Mulberry
is cultivated extensively in Asia for silk production. Mulberry
species are known to be used as timber and also for its
edible parts. Although more than 150 species have been documented,
a majority of them are treated as synonyms or varieties.
One of the major criteria followed for identification of
mulberry species is based on the reproductive characters
such as style length and nature of stigma in female flowers.
In Morus alba, the presence of extremely short and almost
insignificant style in female flower hinders the identification
process of Morus cultivars (Kichisaburominamizawa, 1997).
In addition, fertile hybrids are produced due to its dioecious
feature and cross-pollination among themselves in nature
suggesting that they have a close genetic relationship (Das
et al., 1994). These rare features have created considerable
apprehension about identification of mulberry. Characterization
of mulberry DNA by molecular technique, like Randomly Amplified
Polymorphic DNA (RAPD), and Amplified Fragment Length Polymorphism
(AFLP), is the basis for evaluation of mulberry genotypes.
The genetic identities and relationship of mulberry can
be evaluated with RAPD technology (Zang et al., 1998). The
available information about intra species genetic variation
is meager among mulberry diversity in India.
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