PAPAYA - Tropical Fruits - page 306

governed by quantitative genes with additive ef ects, and hybrids are expected
to have intermediate values between the parents.
Papaya fl esh colour ranges from intense gold to deep red, with varying
intermediate shades (Table 11.2). In Malaysia and many South-east Asian
countries, the preference is the red-fl eshed varieties, while Hawaii and
Australia prefer the yellow-fl eshed types. Flesh colour is governed by a single
gene, with yellow (R) being dominant over red (r). Varying intermediate
shades of pink may be attributed to modifi er gene ef ects. All red-fl eshed (rr)
varieties, such as 'Sunrise Solo' and 'Eksotika', will breed true for fl esh colour,
but progenies of heterozygous (Rr) yellow F 1 hybrids, such as 'Rainbow', will
segregate in this trait.
The skin colour of papaya fruit is usually green when immature, changing
to yellow or reddish-orange when fully ripe. The 'Morib' is an interesting local
selection that has attractive yellow fruit skin even at an immature stage. The
tree is dwarfed and has yellowish-green foliage. Fruit skin colour is governed
by a single gene, with green (G) being dominant and yellow is expressed in a
double recessive (gg). It is dii cult to identify the appropriate harvest index of
this fruit.
The old dioecious cultivars, such as 'Hortus Gold' (South Africa),
'Sunnybank' (Australia), 'Betty' and 'Carifl ora' (Florida) are cross-pollinated,
yellow-fl eshed and typically round fruit. 'Carifl ora' fruits are smaller and
tolerant to the ringspot virus disease. There are also gynodioecious varieties
that are cross-pollinated, such as 'Sekaki', 'Khaek Dum', 'Maradol' and
'Cibinong'. 'Sekaki', also known as 'Hong Kong', is the second most popularly
cultivated cultivar in Malaysia after 'Eksotika'. 'Khaek Dum' is Thailand's best-
known variety and is a vigorous plant that bears red-fl eshed fruit weighing
about 1.2 kg with 10.6% total soluble solids content. 'Maradol' originates
from Cuba, is a short-stature variety that bears fruit very close to the ground.
The fruit weighs from 1 to 2 kg, attractive with fi rm red fl esh and 10-11%

Table 11.2. Preference of fruit characteristics in some countries.
Country Fruit size (g) Shape Flesh colour Race

Australia 800-1000 Cylindrical,

spherical

Yellow Dioecious

Cook Islands 500-1134 Pyriform Yellow Hermaphrodite

Fiji 397-510 Pyriform Red, yellow Hermaphrodite

Hawaii 397-510 Pyriform, oval Yellow, red Hermaphrodite

Mexico 1360-5443 Spherical,

elongate

Yellow, red Dioecious,

hermaphrodite

South Africa 1000-1500 Oval Yellow Dioecious

Caribbean
Islands

500-4000 Round, oval,

pyriform,
elongate

Red, yellow Dioecious,

hermaphrodite