Banana is one of the most popular fruit in the world and it is believed that 100 billion bananas are consumed over the year. About 159 nations in the world grow bananas producing 105 million tones of fruit each year. Banana is known for its mineral-rich traits, and globally it is traded more than any other fruit.
The history of bananas begins in South-East Asia. It was brought to the west by Arabs during the 327 B.C while it moved from Asia Minor to Africa before it finally spread to the New World to the Caribbean.
Bananas were cultivated since ancient times. Sailors carried the banana to the Canary Islands and the West Indies and finally found its way to North America by the Spanish missionary Friar Tomas de Berlanga.
At present, banana cultivation takes place in most tropical regions and is also widely consumed in these regions. Banana is recognized for its flavorful taste and is popular due to its availability throughout the year. Among many varieties in banana, cavendish or dessert bananas are mostly consumed around the world.
This fruit is rich in dietary fiber and has a high carbohydrate content (22 percent). It is also rich in manganese, vitamins B6 and C, and potassium. Due to its high nutritional traits, banana is majorly exported from Ecuador, Honduras, Panama, and Costa Rica to rest of the world. North America remains the major consumer of banana fruit. It is widely grown in Asia including India and Sri Lanka.
Besides all the benefits of this delicious superfood, banana is prone to various diseases as well.
- Fusarium or the Panama Disease
Fusarium or the Panama Disease hits the banana crop at large and it was carried through the soil. Fusarium soil fungus enters the banana plant through the roots and uses water to travel into the leaves and the trunk. It restricts the flow of water and nutrients to cause wilting.
- Tropical race 4 or TR4
Discovered in 1993, TR4 is a reinvigorated strain of Panama disease that destroyed Cavendish banana in Southeast Asian countries including India and Australia. This banana variety is highly sensitive towards TR4. Building genetic resistance can only save this variety by developing the appropriate defense mechanism using technological innovations.
- Black Sigatoka
The 1920’s banana crop was hit by Sigatosa- an air-borne fungus that ruined the banana crop at large. Black Sigatoka was first discovered in 1964 around Fiji. It is a fungal leaf spot disease that affects all major banana cultivars. Intensive spraying was used to keep the disease at bay but now the fungus has developed resistance to spray treatment. In this scenario, scientists are considering gene editing to overcome this disease.
- Banana bunchy top virus
Banana bunchy top virus (BBTD) disease affects the leaves by making them shorter and stunted in the form of a bunch at the apex of the plant. It makes a plant infertile and stops producing any fruit. This virus hails transmission from aphid Pentalonia nigronervosa and is widespread in the Philippines, South-East Asia, Asian Taiwan, and parts of Africa.
- Banana bacterial wilt
This is a bacterial disease caused by Xanthomonas campestris pv. Musacearum and it was first observed in Uganda in 2001, affecting all banana cultivars. Banana crop cultivated in Central and East African regions is highly affected by this bacterial disease.
Africa has taken keen steps for managing banana diseases and protecting the banana crop through various ongoing research in the region. A recent study by the scientists from the International Institute of Tropical Agriculture (IITA) in Nairobi validates that advances in the gene-editing application CRISPR can improve banana cultivars. The new CRISPR/Cas9- editing system developed by the IITA enables disease resistance in the banana crop.
This study aims to fill the yield gap in staple crops for improving food production. Agricultural productivity can get an optimum boost through the CRISPR application. IITA researchers are focusing on developing disease resistance variety through the new CRISPR/Cas9- editing system to combat the banana Xanthomonas wilt (BXW) disease. It is affecting banana production in East and Central Africa. IITA researchers claim that knocking down MusaDMR6 in bananas enhances resistance to BXW.
This is certainly a major advancement and a laudable effort from the researchers at IITA that has put gene editing as a promising technology to breed sustainable varieties.