Effect of the Seedlessness (Fs) Gene in Fruit Quality Traits in Mandarin Segregating Populations

Abstract

Xenia and metaxenia effects can be responsible for variation in fruit size, fruit shape, and sugar content in fruit. In the process of developing new mandarin citrus hybrids, the University of Florida Fruit Tree Breeding Program produced four populations segregating for the seedlessness gene Fs.The objective of this research was to determine if the presence or absence of seed had xenia-like effects on the mandarin hybrids. The four populations contained a total of 213 trees. The fruit produced by these trees were evaluated by sampling three random fruit and measuring the soluble solids concentration (SSC) of each fruit. Additionally, the fruit were scored for the presence or absence of a fruit neck at the stem end. There were no statistically significant differences between seedless and seeded offspring in the four hybrid populations for fruit weight (g) or SSC (% w/w). The "neck" phenotype also appears to be controlled by a single locus and follows a Mendelian segregation ratio of 3:1 (neck: flush). These results support the use of the seedless gene Fswithout negative effects on fruit size and sugar concentration in the resulting progeny.