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Abstract:
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S. album L. is the source of highly priced and fragrant heartwood which on steam
distillation yields on an average 57
per cent oil of high perfumery value. Global
demand for sandalwood is about 5000-6000
tons/year and that of oil is 100 tons/year.
Heartwood of sandal is estimated to fetch up to Rs. 3.7 million/ton and wood oil
Rs.70,000-100,000/
kg in the international market. Sandal heartwood prices have
increased from Rs. 365/ton in 1900 to Rs. 6.5 lakhs/ton in 1999-2000
and to Rs. 37
lakhs/ton in 2007. Substantial decline in sandalwood production has occurred from 3176
tons/year during 1960-‘
65 to 1500 tons/year in 1997-98,
and to 500 tons/year in 2007.Depletion of sandal resources is attributed to several factors, both natural and
anthropogenic. Low seed setting, poor seed germination, seedling mortality, lack of
haustorial connection with host plant roots, recurrent annual fires in natural sandal
forests, lopping of trees for fodder, excessive grazing, hacking, encroachments, seedling
diseases and spread of sandal spike disease are the major problems facing sandal. While
these factors hinder sandal regeneration in forest areas, the situation is accelerated by
human activities of chronic overexploitation
and illicit felling.Deterioration of natural sandal populations due to illicit felling, encroachments and
diseases has an adverse effect on genetic diversity of the species. The loss of genetic
diversity has aggravated during recent years due to extensive logging, changing landuse
patterns and poor natural regeneration. The consequent genetic erosion is of serious
concern affecting tree improvement programme in sandal. Conservation as well as mass
propagation are the two strategies to be given due importance. To initiate any
conservation programme, precise knowledge of the factors influencing regeneration and
survival of the species is essential. Hence, the present study was undertaken with the
objective of investigating the autotrophic and parasitic phase of sandal seedlings
growth, the effects of shade on morphology, chlorophyll concentration and chlorophyll
fluorescence of sandal seedlings, genetic diversity in sandal seed stands using ISSR
markers, and the diversity of fungal isolates causing sandal seedling wilt using RAPD
markers. All these factors directly influence regeneration and survival of sandal
seedlings in natural forests and plantations. |