Annona Species Monograph.pdf - Crops for the Future

Chapter 8. Genetic Resources
There is an urgent need to survey and collect wild materials, primitively
cultivated forms and varieties of Annona species. However, primary
emphasis needs to be on improving the agronomic and economic yields of
each species in the range of habitats where they are grown.
A total of 1,741 germplasm accessions of eleven identified species, one
interspecific hybrid and various Annona spp. are documented (IPGRI, 2000),
with a surprisingly low percentage of duplication across the 67 institutional
collections in 34 countries (Table 8.2). Due to their commercial importance,
the three species with the largest number of accessions are A. cherimola, A.
muricata and A. squamosa.
Considering that almost all conserved Annona germplasm is maintained in
field collections, which are subject to abiotic and biotic stress conditions,
such as flooding, drought, pathogen or insect infestations, the low percentage
of duplication is a matter of considerable concern. The first step to remedy
this has been taken by the Spanish government, in co-operation with IPGRI,
through the establishment of a cherimoya genebank in Peru (Coppens
d'Eeckembrugge et al., 1998). Besides this cherimoya genebank, Ecuador is
establishing an Annona collection on the same basis as the Peru genebank (G.
Coppens d'Eeckembrugge, Cali, 2001, personal communication). Other
actions are needed, since these two actions only target cherimoya.
A global strategy for collecting, evaluating and conserving germplasm needs
to be thought out and implemented. This is particularly important since
Annona collections are scarce in most of the major areas of diversity, such as
Honduras, Mexico and the Antilles. In addition, the need of long-term
financial commitment for germplasm banks, especially field genebanks of
fruits in their centres of diversity, is important. It was observed in Amazonia,
for example, that various collections were in advanced stages of
deterioration. In part, this is due to a lack of breeders using the collections,
although these collections are valuable as sources of genetic materials for
testing in different areas or for exchanging among countries even if breeders
are not locally available (Arkcoll and Clement, 1989).
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