New Plantain Hybrids Resistant to Black Sigatoka
Using techniques involving basic, strategic, and applied research, the International Institute of Tropical Agriculture (IITA) in Nigeria has developed hybrid plantains
resistant to black sigatoka, a leaf spot disease that is generally considered to be
the most serious constraint to banana and plantain production (Musa spp) in Sub-Saharan Africa. The region produces about
75% of the world's plantain. The gross value of Musa production in Sub-Saharan Africa is said to exceed that of several other main food crops, including maize,
rice, and cassava. Musa also provide an important source of income for rural smallholders.
Symptoms of black Sigatoka on plaintains
Caused by the fungus Mycosphaerella fijiensis, black sigatoka is particularly devastating for plantain production, causing yield reductions of 30-50% in Sub-Saharan Africa. Previous research to remove biotic and abiotic stresses in Musa was limited, in part due to indications that the crop was intractable to genetic improvement by classical methods, since most cultivated Musa are triploids and, therefore, are almost completely sterile.
The breeding methodology adopted by IITA involves the production of tetraploid hybrids by triploid x diploid crosses. The susceptible triploid parent produces unreduced triploid eggs, while the diploid male-fertile parent, producing normal haploid pollen, serves as the source of genes for black sigatoka resistance. Since 1987, IITA has developed parthenocarpic plantain germplasm resistant to black sigatoka through a combination of conventional and new approaches, including interspecific hybridization, ploidy manipulations, in vitro culture, field testing, and selection. In the process, more insight has been gained into Musa genetics, resulting in the emergence of new breeding strategies for the improvement of bananas and plantains.
In its research to develop black sigatoka resistant plantain hybrids, IITAcollaborated with twelve national agricultural research systems in Sub-Saharan Africa and Latin America as well as with the International Network for the Improvement of Banana and Plantain (INIBAP) in France and a number of advanced laboratories in Belgium and the USA. The resistant hybrids are expected to increase household revenue for smallholders and reduce dependence on chemical control strategies. The higher yields may also reduce the need to expand cultivation to larger land areas. These developments will contribute to food security in Sub-Saharan Africa, increase income generation for smallholders, and enhance the sustainability of Musa production.
(IITA/Technical Advisory Committee)