The genome diversity of major crops tells the story of their evolution

A recent study published in Nature has successfully sequenced the complex genome of sugarcane, a significant advancement given its polyploid nature and size, which is 20 times larger than that of rice. This research highlights the importance of understanding crop genomes, as they reflect the evolutionary history shaped by human selection in diverse environments. For instance, rice has evolved through natural mutations and crosses in the Himalayas over 10,000 years, leading to a wide variety of cultivars. Sugarcane, originating from Southeast Asia, showcases extensive genetic mixing, enhancing its disease resistance and biomass production capabilities.

CIRAD has been at the forefront of tropical plant genome research since 1986, contributing to the genetic mapping of various crops, including cocoa, bananas, and coffee. The study of cocoa's genome diversity, for example, reveals its ancient dissemination and adaptation, while bananas and citrus fruits demonstrate the effects of hybridization on their genetic diversity. Arabica coffee, resulting from a unique hybridization event, underscores the need for ongoing genetic exploration to maintain diversity for future adaptations.

The research emphasizes the necessity of conserving genetic resources and developing new crop varieties to address challenges like climate change. By leveraging genomic data, scientists aim to enhance crop resilience and sustainability, ensuring food security while navigating societal and ethical considerations surrounding genetic modification and access to agricultural knowledge.