Protocols for Micropropagation of Woody Trees and Fruits

2.1. Explant Preparation
MICROPROPAGATION OF PINEAPPLE
2. EXPERIMENTAL PROTOCOL
2.1.1. Pineapple Varieties That Can Be Micropropagated
Cultivated types of pineapple are called clones because they are vegetatively
propagated and are self sterile but cross easily with plants outside their varietal
group (Evans et al., 2002). There are many commercial clones (Table 1) classed in
4–5 groups including ‘Cayenne’, Spanish’, ‘Queen’ and ‘Pernambuco’ which may
represent botanical varieties. The most popular variety for micropropagation in
many parts of the world is cv. Smooth Cayenne Serrana (Daquinta and Benegas,
1997) but some others such as, cvs. Queen, Kew, Giant Kew and Mauritius are also
widely cultivated in other regions.
Table 1. Commercially sold pineapple varieties.
Leading type (cv) Countries involved in
cultivation
Remarks
Smooth Cayenne Thailand, Philippines,
Hawaiian Islands
Most commonly available
Queen South America, Smaller, little drier and less sweet
Australia, India than Smooth Cayenne
Red Spanish Caribbean
Medium sized, purple-hued skin,
light yellow flesh
Pernambuco Medium sized
Sugarloaf Large and heavy
Baby
MD2 (‘Extra
Sweet’ or ‘Golden
Ripe’)
Very sweet
Europe Sold as fresh fruit
2.1.2. Supply of Plant Material
Explant – Dormant Axillary Buds from Crowns. Crowns from harvested ripe pineapple
fruits can be used as source of dormant axillary buds for culture initiation.
Conventionally, after removal of all the leaves the base of the crown is sectioned
and each quarter is then planted to yield a single plant. Beneath each leaf of the
crown is a 1–2 mm sized dormant bud (nearly 12–15 buds per crown) which remains
dormant in this cultivation method. However, under in vitro conditions it is possible
to scoop out this bud and culture it on defined medium so that it can be made to
sprout and yield numerous tiny shoots. Each shoot can be subsequently rooted to
obtain a complete plant. However of the 12 to 15 buds present in each crown, only
the larger 8–10 buds in the middle portion of the crown have the potential to sprout
in culture (Soneji et al., 2002a).
501