ABSTRACT
Naturally occurring genetic variation in the universal florigen flowering pathway has produced major advancements in crop domestication. However, variants that can maximize crop yields may not exist in natural populations. Here we show that tomato productivity can be fine-tuned and optimized by exploiting combinations of selected mutations in multiple florigen pathway components. By screening for chemically induced mutations that suppress the bushy, determinate growth habit of field tomatoes, we isolated a new weak allele of the florigen gene SINGLE FLOWER TRUSS (SFT) and two mutations affecting a bZIP transcription factor component of the 'florigen activation complex' (ref. 11). By combining heterozygous mutations, we pinpointed an optimal balance of flowering signals, resulting in a new partially determinate architecture that translated to maximum yields. We propose that harnessing mutations in the florigen pathway to customize plant architecture and flower production offers a broad toolkit to boost crop productivity.
Subject(s)
Florigen/chemistry , Flowers/genetics , Mutation , Solanum lycopersicum/genetics , Alleles , Amino Acid Motifs , Chromosome Mapping , Crops, Agricultural/genetics , Genotype , Heterozygote , In Situ Hybridization , Meristem/genetics , Phenotype , Plant Leaves/genetics , Plant Proteins/genetics , Plant Shoots , RNA, Messenger/metabolism , Transcriptome , Two-Hybrid System TechniquesABSTRACT
Polyploidy is a pivotal process in plant evolution as it increase gene redundancy and morphological intricacy but due to the complexity of polysomic inheritance we have only few genetic maps of autopolyploid organisms. A robust mapping framework is particularly important in polyploid crop species, rose included (2nâ=â4xâ=â28), where the objective is to study multiallelic interactions that control traits of value for plant breeding. From a cross between the garden, peach red and fragrant cultivar Fragrant Cloud (FC) and a cut-rose yellow cultivar Golden Gate (GG), we generated an autotetraploid GGFC mapping population consisting of 132 individuals. For the map we used 128 sequence-based markers, 141 AFLP, 86 SSR and three morphological markers. Seven linkage groups were resolved for FC (Total 632 cM) and GG (616 cM) which were validated by markers that segregated in both parents as well as the diploid integrated consensus map.The release of the Fragaria vesca genome, which also belongs to the Rosoideae, allowed us to place 70 rose sequenced markers on the seven strawberry pseudo-chromosomes. Synteny between Rosa and Fragaria was high with an estimated four major translocations and six inversions required to place the 17 non-collinear markers in the same order. Based on a verified linear order of the rose markers, we could further partition each of the parents into its four homologous groups, thus providing an essential framework to aid the sequencing of an autotetraploid genome.
