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Sugarcane
is an industrial crop with acreage of about 4 million hectares
and production to the tune of 300 million tonnes in India. It
provides employment to over a million people directly or indirectly
besides contributing significantly to the national exchequer.
In commercial agriculture, cane is subjected to various weather
conditions and stresses. In the Indian subtropics erratic availability
of moisture and frequent occurrence of red rot disease severely
impair the productivity of cane. In addition to this, acute water
scarcity in many areas would need the development of drought tolerant
/ water use efficient cane genotypes to sustain the cane industry
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The commercial sugarcane is no longer pure Saccharum officinarum
but a species hybrid, complex polyploid with a large number of
chromosomes. This does not offer a clean system for genetic manipulation
through conventional means. As a result, inheritance of most of
the characters of interest for varietal breeding is not thoroughly
worked out, so much so that neither the number of genes nor the
nature of gene action governing the expression of these traits
is fully known. Thus sugarcane has remained geneticists' nightmare.
With
the advancement of molecular biology, newer techniques have become
available to unravel the sugarcane genome. Monitoring of differential
tissue-specific gene expression in genotypes of contrasting genetic
potential for traits under study by expressed sequence tagging
may be used as a technique to get an access to the complexity
of gene function in sugarcane. Development of ESTs in sugarcane
is already in progress in some cane growing countries (in fact
in a big way in Brazil) It is expected that the proposed work
would reinforce this international endeavour and provide specific
benefits to Indian sugarcane cultivation.
Identification
of genes in sugarcane against various stresses may help better
understanding of the underlying physiological mechanisms of resistance/tolerance
and facilitate genetic manipulation to tailor the sugarcane plant
to cope with these stresses. Sugarcane, owing to its vegetative
propagation and genetic complexity, is easily amenable to biotechnological
applications like the production of transgencis and the DNA analysis
of segregating population to effect early selection for the trait
of interest (marker assisted selection). The proposed EST approach
shall identify and make available genes for stress endurance and
allow their incorporation in the reigning sugarcane varieties
through genetic transformation. |
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