By ROSA KAMBUOU
BANANA is the most important staple food crop of PNG, ranking second to sweet potato (kaukau) in production and consumption.
It is grown throughout the country, especially the “cooking types”, which comprise mostly of the edible diploids, the triploids and some tetraploids.
The edible diploid, AAs and the ASs, are grown mainly in high rainfall areas of the country while the triploid, AABs, are mostly cultivated in the highlands and a certain group of triploid, ABBs, commonly known as kalapuas, is quite common in gardens in dry lowland areas of PNG.
The world focus on bananas is on the “dessert types”, which are consumed raw when ripened and are usually distinguished by the sweet flavour of the fresh fruits when ripe.
The most popular international dessert banana variety is cavendish, which is grown by most banana-growing countries of the world.
There are three varieties of cavendish recorded in PNG and are identified by their status and heights; the dwarf type (1.0-1.5m high), the medium variety (2m high) and the tall variety (over 2m high).
Two common farmer cultivars of dessert bananas of PNG are yawa and Sogeri biku. Most of the dessert varieties (cultivars) have white to light yellow fruit flesh when ripened.
PNG is an important centre of diversity for musa species, especially the “cooking types” from all three genomic groupings of diploids, triploids and the tetraploids.
The national banana germplasm gene-bank housed at NARI’s Southern regional centre, Laloki, has 217 accessions of bananas. At one stage, around 500 accessions were collected and recorded.
It is believed that there are more than 217 accessions of bananas grown and consumed in the country.
PNG is one of the very few countries in the world that is still consuming the primitive diploid AA and AS cultivars. Some of these cultivars still have sterile black seeds which are seen when cooked.
This genomic group of bananas contributes some very important cultivars in terms of their “nutritive values”.
The NARI plant genetic resources and the banana research and development team at Laloki is currently engaged in a study, looking at the carotenoid (pVACs) contents of PNG banana diversity.
The study so far revealed that most diploid cultivars contain very high levels of pVACs.
So far, 10 banana cultivars were analysed for their carotenoid contents and another 10 are being analysed.
A total of 40 cultivars will be analysed through this study.
Preliminary findings so far revealed some PNG diploid AA cultivars having high levels of pVACs contents, ranging from 1,276-3,428 µg/100g samples.
Carotene is rich in Vitamin A, a nutrient in the food that is responsible for reducing or controlling night blindness, diabetes, heart and kidney problems and also improves the human immune system.
The list of PNG banana accessions sent to Fiji laboratory, with their genomic groupings and the results of a-carotene, the ß-carotene and the total carotene levels, are presented in the table above.
Cultivar manameg red (PNG 161) has the highest level of both a and ß carotenes with the total carotene level at 3,428µg per 100g of samples tested.
Other cultivars with total carotene levels of over 1,000µg per 100g of samples were iriwa, dagere, suruh (PNG 306) and gunih (PNG 168). All these cultivars, with high carotene levels, are from the diploid AA genomic grouping and are commonly grown in areas where rainfall is high throughout the year.
The cultivar that featured poorly in the total carotene level with 271µg per 100g of samples is kurisa, a very popular fast-cooking banana in the drier areas of Central.
Most banana cultivars selected for this study are from the AA genome because of their yellow/orange fruit flesh colour.
For comparison purposes, few triploid AAB cultivars were selected for analyses.
The preliminary results suggested that A gene in these cultivars is responsible for the high levels of carotenoids (pVACs) in the bananas.
We now know that A gene is contributed by the wild species musa acuminate which grows abundantly in the rainforest habitats where rainfall is high throughout the year.
These habitats are also home to some of PNG’s priced timber species, so do we continue to destroy these habitats for short-term income-earning opportunities from timber or we need to protect these habitats because they contain valuable “wild crop relatives” that may provide answers to the food and nutritional security for future generations.
The common lifestyle diseases affecting our urban population, especially the working class citizens of our country, are diabetes, heartaches and kidney failure due to high consumption of fast and oily foods as well as processed foods.
Our own locally grown food crop species like bananas are very rich in nutrition and also provides protection against diseases and improves the body’s immune system.