Tamarind monograph.pdf - Crops for the Future

Divakara, 2002; Shanthi, 2003). A maximum heritability of 0.5 and the
highest genetic advance percentage were recorded over a mean of 42.5 for
pulp weight (Table 7.2). The highest genetic advance was observed for pulp
weight. Pod length showed highest positive phenotypic correlation with
pulp weight. Hence, selection based on pulp weight and pod length is useful
in tamarind improvement programmes. Further, because of the presence of
significant positive correlation coefficients between pod length and pod
width, they are suggested as selection criteria for the identification of
superior trees.
Table 7.2 Heritability and genetic advance of tamarind
Character Heritability Genetic advance percentage
over mean
Pod length 0.30 16.3
Pod width 0.40 10.0
Pulp weight 0.50 42.5
Number of seeds/pod 0.20 13.6
Single seed weight 0.05 2.2
Source: Shanthi (2003).
7.3 Genetic improvement
Genetic improvement through the use of superior clones has been described
by Kulkarni et al. (1993). Tamarind has a relatively long generation time and
is primarily outcrossing, thus any conventional breeding approaches would
require considerable investment in time and money. There are trees with
very high yielding potential exceeding 800 kg/tree/year and such trees could
be selected for vegetative propagation by air layering or grafting methods to
produce fast growing trees for local (home garden) and commercial
(orchard) use. Such trees can be grown with comparative ease and minimum
management and should prove to be profitable due to their commercial value
for small-scale farmers in African and Asian countries.
Provenance trials need to be conducted in many parts of the tropics to select
the best germplasm for further improvement. Germplasm needs to be
rigorously characterised and evaluated to select desirable traits. If quick
growing and high yielding strains are selected for different uses, tamarind
would rapidly become a desirable tree for small scale plantations in a short
period, particularly since it continues to bear fruit for many years. More
trait specific research and combining desirable characters together is needed
to develop cultivars. An emphasis should be to select for agroforestry
systems and small scale plantations. The desirable ideotypes should be
developed to fit into various niches of these systems as well as for more
intensive commercial production. This will require more attention to tissue
culture since it offers a way of cleaning stocks from diseases. Then planting
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