Homegarden-based Indigenous Fruit Tree Production in Peninsular India - Indigenous Fruit Trees in the Tropics: Domestication, Utilization and Commercialization - page 91

5.4.2 Genetic diversity of indigenous fruit trees
Aside from floristic richness, several of the indigenous fruit trees exhibit
considerable intraspecific variations in tree growth, phenology of flowering, and
fruit characters (Table 5.2). This is consistent with the observations of Watson and
Eyzaguirre (2002), who reported that several landraces and cultivars, as well as
rare and endangered species, are preserved in homegardens. Contemporary
patterns of genetic variation in homegarden components, however, reflect the
historical processes associated with domestication, such as the geographical
origin(s) of the cultivated populations, interpopulation genetic exchange and
ancestry, which influence the genetic structuring of such populations (Schaal et al .,
1998). However, in view of the complex patterns of germplasm exchange
prevailing in many indigenous cultures and the multiple origins of cultivated plant
populations, it is difficult to make firm generalizations. Furthermore, only limited
research on population genetics and systematics, in order to characterize this
diversity and understand the mechanisms through which it arises, has been done
in Peninsular India. The high degree of genetic diversity observed in the Kerala
homegardens (Table 5.2), nevertheless, ensures compliance with the Convention
on Biological Diversity (CBD) on aspects such as ex situ biodiversity conservation.
5.4.3 Utilizing and conserving homegarden genetic resources
In certain cases, the rich genetic diversity of fruit trees has been utilized in clonal
selection programmes, which have led to the development of many commercial
varieties. For example, in mango about 30 varieties have been developed in India
(Ghosh, 1998). However, traditional mango varieties in the homegardens of
Kerala, which constitute an important segment of the genetic diversity of this crop
(Anila and Radha, 2003), have been largely ignored by organized research. Due
to commercialization, many of these cultivars are also disappearing (Kumar and
Nair, 2004), which calls for urgent steps to be taken to conserve the indigenous
germplasm. Jackfruit, another important product of Kerala homegardens, grows
wild in the forests of the Western and Eastern Ghats of India, besides being
cultivated as a horticultural crop (Ghosh, 1998). Being cross-pollinated and mostly
seed-propagated, it exhibits great variations in fruit characteristics such as density
of spikes on the rind, periodicity of bearing, size and shape, quality, and period of
maturity (Melantha, 1998). Here too, selections involving culinary/table types with
superior traits have been attempted (Ghosh, 1998), but no major conservation
efforts to preserve the native populations are in the pipeline.
5.5 Utilization of Homegarden Products
While a large proportion of the homegarden production is consumed domestically
(30-72%), products such as fruits, vegetables and medicinal/ornamental plants are
also generously shared within the local communities (Kumar and Nair, 2004). In
addition, there are many tree species producing edible fruits and other products,