Genomic models can reduce the time it takes to breed bananas

Scientists have shown that it is possible to speed up banana breeding through genomic prediction models, giving potential hope to banana breeders and smallholders in East Afrika.

Banana, according to Moses Nyine, a research scientist at the International Institute of Tropical Agriculture, Uganda, and a co-author of the study, is an important staple crop for millions of people in Sub-Saharan Afrika, especially those in East Afrika.

“Breeders will increase the breeding efficiency by reducing the cost and time required to deliver high-yielding and disease-resistant varieties to farmers.”Moses Nyine, The International Institute of Tropical Agriculture, Uganda

In a study published in The Plant Genome last month (2 March), researchers collected data on 15 key traits from 307 banana types that were grown in two fields in Uganda under low and high input field management conditions for two crop cycles from 2013 to 2016. The traits were grouped into five categories: plant stature, suckering behaviour, black leaf streak resistance, fruit bunch and fruit filling.

The DNA differences between the bananas were mapped. The researchers assessed the ability of six genomic prediction models to use cross-validation to identify the bananas with the best traits.

“The results demonstrate that genomic prediction is possible in banana breeding and the prediction accuracy can be improved by using models based on data from many different environments,” says Nyine.

Researchers found the accuracy of genomic prediction to be above 75 per cent.

“Breeders will increase the breeding efficiency by reducing the cost and time required to deliver high-yielding and disease-resistant varieties to farmers,” adds Nyine, who is also a doctoral student at Palacký University in the Czech Republic. “Banana breeding is a lengthy and costly process, taking up to 20 years to deliver improved varieties to farmers”.

Smallholders, he explains, will be assured of food security and income despite the numerous pests, diseases and environmental stresses affecting banana in Africa.

Paul Kimani, a professor of plant breeding and genetics from Kenya’s University of Nairobi, tells SciDev.Net that the study demonstrates simultaneous selection of multiple traits of importance not only to farmers but also to other actors along the value chain.

But much more needs to be done to assess performance of the new varieties on the farm and in the market place, according to Kimani. He tells SciDev.Net, “One point that molecular breeders often overlook is that shortening time to develop a new variety is somewhat exaggerated. For instance, this study suggests that it will take about three to five years to develop hybrids using integrated genomic selection compared with 11-14 years for conventional breeding.

“But in reality the period is likely to be about eight to 13 years with genomic selection because the new hybrids still need multi-location and on-farm evaluation: an additional three to four years, and probably another year of sensory evaluation and [consumer] acceptability studies.”


A man with a hoe stands in a banana plantation Copyright: Panos

This article was published by SciDev.Net’s Sub-Saharan Africa English desk.

Comments