Induction, rapid fixation and retention of mutations in vegetatively propagated banana

Abstract

Mutation discovery technologies have enabled the development of reverse genetics for many plant species and allowed sophisticated evaluation of the consequences of mutagenesis. Such methods are relatively straightforward for seed-propagated plants. To develop a platform suitable for vegetatively propagated species, we treated isolated banana shoot apical meristems with the chemical mutagen ethyl methanesulphonate, recovered plantlets and screened for induced mutations. A high density of GC-AT transition mutations were recovered, similar to that reported in seed-propagated polyploids. Through analysis of the inheritance of mutations, we observed that genotypically heterogeneous stem cells resulting from mutagenic treatment are rapidly sorted to fix a single genotype in the meristem. Further, mutant genotypes are stably inherited in subsequent generations. Evaluation of natural nucleotide variation showed the accumulation of potentially deleterious heterozygous alleles, suggesting that mutation induction may uncover recessive traits. This work therefore provides genotypic insights into the fate of totipotent cells after mutagenesis and suggests rapid approaches for mutation-based functional genomics and improvement of vegetatively propagated crops.

Plant defense response against Fusarium oxysporum and strategies to develop tolerant genotypes in banana

“…However, it is a complex process to employ in vegetatively propagated plants. Jankowicz-Cieslak et al (2012) group has developed a method by treating banana shoot apical meristems with the chemical mutagen ethyl methanesulphonate and recovered high density of GC-AT transition mutations showing that mutant genotypes are stably inherited in subsequent generations. They suggest that it therefore provides genotypic insights into the fate of totipotent cells after mutagenesis and suggests rapid approaches for mutation-based functional genomics and improvement of vegetatively propagated crops.…”

Mutation Induction Using Gamma Irradiation and Embryogenic Cell Suspensions in Plantain (Musa spp.)

“…The regenerated mutant plants will be potentially unstable in regard to cellular genotypes and expressed phenotypes due to segregation in subsequent vegetative propagated generations. Interestingly, data from chemical mutagenesis of triploid bananas suggests that chimaerism can be quickly resolved and may not be an issue in some cases (Jankowicz-Cieslak et al 2012). Similar data is not available for gamma irradiation, and therefore several rounds of subculturing are advised to remove chimaeras (see Chap.…”

Introduction

“…TILLING has been applied to over 20 plant and animal species, and similar approaches have been used to characterize naturally occurring nucleotide variation, known as Ecotilling Jankowicz-Cieslak et al 2011). While TILLING and Ecotilling have been primarily used in seed crops, the methods work well in vegetatively (clonally) propagated and polyploid species such as banana and cassava (Jankowicz-Cieslak et al 2012;Till et al 2010). The PBGL has developed low-cost methods for the extraction of enzymes from a variety of plant materials, including easily obtainable weedy plants.…”