Agriculture Reference
In-Depth Information
fi elds can revert to conditions of an unselected fi eld population. In Hawaii,
advanced hybrid clones were derived from many years of breeding (Chan
et al.
, 2003). In Australia, sources of germplasm consist of selections from
Queensland 'Cayenne' clones, hybrid populations, meristem-cultured plants
from known clones and introductions from other countries. Hybrid selections
were derived from 'Cayenne' crosses with rough leaf types such as 'Queen',
'Ripley Queen', 'MacGregor', 'Alexandra' and 'Collard'. 'Singapore Spanish', a
spineless plant with good fruit quality, has been widely used in their breeding
programme. Malaysia has similarly used 'Smooth Cayenne' and 'Singapore
Spanish' in their hybrid breeding programme. Breeding programmes in Puerto
Rico, Brazil, Taiwan, the Philippines and South Africa maintain the major
cultivars in their germplasm collections.
'Smooth Cayenne' is highly susceptible to mealy bug wilt (Table 12.1),
though a few clones have shown variable resistance, which is transmitted to
seedling progenies. Other cultivars and species have shown some resistance:
'Red Spanish', 'Pernambuco', 'Queen',
Ananas
ananasoides
,
Ananas bracteatus
,
Pseudananas sagenarius
and some hybrids involving 'Cayenne' and resistant
cultivars (Collins, 1960). In Hawaii, hybrid No. 59-656 is resistant to
P. cinnamoni
and
Phytophthora parastica
root and heartrot diseases.
Concomitant with breeding for disease and insect resistance has been the
attempt to develop cultivars suitable for fresh fruit export. A suitable clone
should have high yield, high sugar, a good balance of sugars to acids, high
ascorbic acid and appealing fl avour. These must be incorporated in a clone
having the desired disease resistance, fruit shape and weight.
Cultivars
Collins (1960) developed a botanical key to the genera and species and the
major characteristics of fi ve 'Cayenne' clones for selection of appropriate
parents. A later taxonomic key identifi ed 18 commercial clones with
vernacular names and descriptions (Antoni and Leal, 1980); this included a
new group, 'Maipure', composed of smooth-leaved clones (Table 12.1). Clones
in this group are primarily grown in South America. The major fruit and leaf
characteristics of the principal clones can be placed in fi ve phenotypic groups
(Table 12.1). 'Monte Lirio' and 'Perolera', formerly unclassifi ed, are placed
in the 'Maipure' group. 'Cayenne' and 'Maipure' smooth-leaved groups dif er
in that leaves of the former group exhibit a few spines near the leaf tip, while
the latter group shows leaf piping (leaf margins) with a greyish streak, due
to folding over of the lower epidermis on to the upper leaf surface (Collins,
1960). Pineapple isozyme variation indicates fi ve genetically diverse groups
that do not perfectly match these phenotypic groupings (Loison-Cabot, 1992;
Aradhya
et al.
, 1994). A brief discussion of the fi ve horticultural groups
follows.
Cayenne
group: 'Smooth Cayenne' is the standard for processing and
for the fresh fruit trade because of its cylindrical shape, shallow eyes, yellow
