Genetically Marked Male Sterile Genes and Hybrid Seed Production. Final Report on Phase 2

摘要

The project was intended to make practical the use of nuclear male sterile (ms) genes in hybrid seed production by linking a marker gene to the male fertile allele of the ms gene and selecting for the segregating ms seed by discarding segregants showing the phenotype associated with the marker gene. Researchers devised a transformation protocol for melon using Agrobacterium tumefaciens, and obtained transformed plants containing a number of marker genes. The most useful marker, the luciferase gene, luc, from firefly, can be detected and sorted reliably at the seed stage. The transformation protocol was not efficient enough to produce linkage of the marker by random introductions, so a strategy based on isolation of an ms gene using Ac tagging was assessed. Transformants containing Ac constructs were obtained and excision of Ac using the polymerase chain reaction was demonstrated. It was concluded that, to produce marked ms in melon, a more efficient transformation system that does not produce chimeras must be devised.