FASCICULATE regulates plant architecture including cluster flower and plant height in pepper (Capsicum annuum)

Abstract

The overall plant shape is determined by genetic program. Regulation of plant architecture is an important agronomic trait for agricultural plants. Capsicum annuum MicroPep shows cluster flowers and short height. By contrast, C. annuum Jeju shows typical pepper architecture. In this study, we crossed C. annuum MicroPep and C. annuum Jeju to identify the genetic loci controlling plant architecture. A total of 117 F2 plants were genotyped using genotyping-by-sequencing (GBS) method and 2,612 single nucleotide polymorphisms (SNPs) were detected. Linked SNPs with same genotype were called as bin, and 1,731 cM bin map with 983 bins were constructed. Using bin map and the phenotype of F2 population, one locus determining MicroPep and Jeju plant shape was mapped on chromosome 6. This locus was also identified to control the plant height from quantitative trait locus (QTL) analysis, while there were 5 additional QTLs on chromosome 1 and 11 for plant height. At this locus of chromosome 6, FASCICUATE (FA) was colocalized indicating that this gene is a strong candidate for the gene controlling the cluster flower phenotype and plant height. This locus can explain 24% of total phenotypic variations. The successfully identification and characterization of FA gene can provide a chance for study of architecture in pepper.