Conventional and modern breeding technologies for improving dwarf coconut cultivars: A review

Coconut (Cocos nuciferaL.) is a multipurpose plantation crop with versatile uses, including as a refreshing drink, edible oil, and, nutraceuticals. Its nutraceutical properties have increased demand in global markets. However, coconut productivity remains low owing to inadequate improved planting materials. This challenge has created a high demand and low supply gap in the coconut industry, which needs to be addressed through breeding methods that can increase productive cultivars in a shorter time. Breeding methods, such as mass selection and hybridization between dwarf and tall cultivars, are the main coconut improvement methods because of their simplicity and ease of use. The hybrids produced, however, take a long time (4-6 years) to bear fruits due to genes inherited from tall parents. Dwarf hybrids that bear fruits in a shorter time (3 years) are less exploited. Developing these coconut types through efficient breeding methods can fill the supply and demand gaps created in the coconut industry. Marker-assisted selection and multi-omics, have been used to identify quantitative traits of agronomic importance to increase genetic gains in dwarf coconut cultivars. This review article summarizes the advances in coconut improvement through conventional breeding, marker-assisted selection, and multi-omics approaches, focusing on dwarf coconut cultivars.