Identification and characterization of GLOBE, a major gene controlling fruit shape and impacting fruit size and marketability in tomato

Within large-fruited germplasm,fruit size is influenced by flat and globe shapes.Whereas flat fruits are smaller and retain better marketability,globe fruits are larger and more prone to cuticle disorders.Commercial hybrids are often developed from crosses between flat and globe shaped parents because flat shape is thought to be dominant and fruit size intermediate.The objectives of this study were to determine the genetic basis of flat/globe fruit shape in large-fruited fresh-market tomato germplasm and to characterize its effects on several fruit traits.Twenty-three advanced single plant selections from the Fla.8000×Fla.8111B cross were selectively genotyped using a genome-wide SNP array,and inclusive composite interval mapping identified a single locus on the upper arm of chromosome 12 associated with shape,which we termed globe.A 238-plant F 2 population and 69 recombinant inbred lines for this region from the same parents delimited globe to approximately 392-kilobases.A germplasm survey representing materials from multiple breeding programs demonstrated that the locus explains the flat/globe shape broadly.A single base insertion in an exon of Solyc12g006860,a gene annotated as a brassinosteroid hydroxylase,segregated completely with shape in all populations tested.CRISPR/Cas9 knock out plants confirmed this gene as underlying the globe locus.In silico analysis of the mutant allele of GLOBE among 595 wild and domesticated accessions suggested that the allele arose very late in the domestication process.Fruit measurements in three genetic backgrounds evidenced that globe impacts fruit size and several fruit shape attributes,pedicel length/width,and susceptibility of fruit to weather check.The mutant allele of GLOBE appears mostly recessive for all traits except fruit size where it acts additively.

Long‑read DNA sequencing leads to the more complete sequence characterization of the fruit size reducing region flanking a Fusarium wilt resistance gene

Introduction Fruit size is an important trait for fruit crops including tomato(Solanum lycopersicum).It influences yield,which is the top priority for plant breeding and improvement programs.Studies have shown that introgression of disease resistance,often a necessity for successful cultivar development,impacts negatively on yield(Ning et al.,2017).Therefore,genetic resources,which do not compromise existing traits except for the new trait of interest,are always in high demand as such resources can be highly beneficial for rapidly incorporating new trait(s)into breeding backgrounds.Given this,exploiting knowledge of these negative impacts at the DNA sequence level has been of interest in the(applied)plant science society.