Training manual - The Vetiver Network International

The RAPD technique is based on the amplification of genomic DNA with single primer of
arbitrary nucleotide sequences. These primers detect polymorphism in the absence of specific
nucleotide sequence information, and the polymorphism which functions as genetic markers, can be
used to construct genetic maps. RAPD provide a simple, quick and reliable alternative to identify
genetic variation whereas SSCP originally used as a quick technique to screen for nucleotide
sequence polymorphism of the DNA mutation, has been developed to screen for genetic variants
especially in nucleotide substitution at any position along a region of DNA. The SSCP is a simple
method for detection sequence variations as small as single-base point mutations.
Kresovich et al. (1994) reported that genome of vetivers within the same clones generated
stable RAPD patterns but were able to distinguish between various vetiver accessions. Srifah et al.
(1996) investigated RAPD markers for detection among Vetiveria nemoralis A. Camus and V.
zizanioides Nash. In Thailand. Adams and Dafforn (1999) found that 86% of 121 accessions of
vetiver were appeared to be from a single clone (‘Sunshine’). The genomic relationships of 35
ecotypes of Thai vetivers and related taxa have been intensively studied by Srifah et al (2000)
employing two different techniques of RAPD and SSCP methods. RAPD provided a simple, quick
and reliable alternative to identify genetic variation whereas SSCP was used as to screen for
nucleotide sequence polymorphism of DNA mutation. Although the ecotypic and phenotypic
characterizations have been routinely used to identify vetivers in Thailand, the minor nucleotide
variations may give rise to morphological, physiological and biological differences. The results
showed that both SSCP and RAPD analysis of their DNA polymorphism are sufficient to
distinguish each ecotype of Vetiveria zizanioides Nash and V. nemoralis A Camus.
2.4 The Vetiver System
2.4.1 Uses and Utilization of Vetiver: The main components of the vetiver system are the
uses of live vetiver plant in agricultural (details in Chapter 6) and non-agricultural applications
(details in Chapter 7), and utilization of dry vetiver plant which are by-products of vetiver grown
for soil and water conservation in handicrafts, root thatch, mushroom growing, animal fodder and
feed stuff, industrial products, herbals, etc. (details in Chapter 8). (See also Chart 1)
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