Molecular and cytogenetic techniques (FISH and GISH) for rapid hybrid confirmation to hasten the breeding pace of ornamental geophytes

Abstract

Ornamental geophytes, also called ornamental bulbous plants, are botanically classified as true bulbous, rhizomatous, corm, or tuberous and are some of the most economically important floricultural crops. In addition to the physico-chemical hindrances in reproductive parts, a prolonged juvenile and vegetative period in ornamental geophytes is a hurdle to their breeding process, making it painstaking and costly efforts to introduce a new variety into the market. The molecular cytogenetic breeding techniques, fluorescence in situ hybridization (FISH) and genomic in situ hybridization (GISH) provide avenues for fast and precise hybrid verification, introgression breeding, localization and discrimination of genes to analyse the recombination patterns, ploidy levels, evolution of the genome and parental identification of these species and to establish their relationships. These techniques have been widely and successfully used for the breeding and hybrid development of numerous ornamental geophytes. Despite significant improvements and shifts in plant breeding and genetics with the advent of new and sophisticated technologies, FISH and GISH are still used for hybrid verification and confirmation of genomic constitution and ploidy levels in hybrids. However, their application has been limited to only a few ornamental geophytes, viz., tulips, lilium, narcissus and hippeastrum. Their applicability has not been explored or exploited in other ornamental geophytes. This review provides insight into the application of FISH and GISH techniques in breeding ornamental geophytes and related achievements.