2018 ASHS Annual Conference

Plant architecture, which is the result of both the plant organization and the interaction between the plant and the environment, affects the ornamental value and flower productivity of roses. Thus, it is helpful to understand the genetic basis of plant architecture so that breeding efforts can be directed towards improved architecture. To this end, six rose architectural traits (plant height, number and length of primary shoots, number of nodes on primary shoot, number of secondary/tertiary shoots per primary shoot) were evaluated in May and December of 2015 in College Station, TX in 13 interrelated diploid rose populations segregating for plant architecture types. Number of primary shoots, length of primary shoots, and number of nodes on primary shoots were found to have low to moderate narrow sense heritability and moderately high to high broad sense heritability, making them of particular interest for breeding. These populations were also genotyped for single nucleotide polymorphisms (SNPs) by digital genotyping, a genotyping by sequencing technique and a consensus map was developed using JoinMap 4.1. The software FlexQTL, a pedigree-based approach which uses a Bayesian analysis, was used to detect quantitative trait loci (QTLs) for these plant architecture traits. Future work will involve identifying specific markers for these traits to enable efficient breeding for superior rose architecture.