Genetic Basis of Control in Fruit Mass Via Pedicel Characteristics in Apple Populations
Pedicels are the slender stalks that attach the fruit to the plant. They play a crucial role in fruit development. The characteristics of the pedicel comprise complex traits that are controlled by multiple genes. To study whether genetic control of fruit mass was via control of pedicel characteristics, we used two unique hybrid apple populations: ‘20 Ounce’ x ‘Prairie Fire’ and ‘Edward VII’ x ‘Prairie Fire’. Both ‘20 Ounce’ and ‘Edward VII’ x ‘Prairie Fire’ produce large fruit over 200 g, whereas ‘Prairie Fire’ is a small-fruited crabapple with fruit size less than 2 g. These populations offer the potential to investigate how pedicel attributes relate to apple fruit size. Previous work established a correlation between pedicel characteristics and apple fruit mass. Specifically, pedicel length showed an inverse relationship, while pedicel diameter was directly related to fruit mass. Shorter and broader pedicels were expected to offer the least resistance to water and nutrient flows. We hypothesize that among the genes that control fruit mass, some govern pedicel length and diameter. Quantitative Trait Loci (QTLs) analysis (Linkage mapping) was performed, and 5 QTLs were associated with characteristics such as fruit mass, pedicel length and pedicel diameter with LOD scores of 4 and above. That being said, no common region was associated with both the fruit mass and pedicel characteristics. This does not support our hypothesis and suggests that different regions may be controlling all these traits. Knowledge of QTLs and subsequently genes that affect fruit mass and pedicel characteristics in apple have potential applications in apple breeding and fruit production. The identification and manipulation of these genes holds the promise of developing new apple cultivars with improved pedicel traits and ultimately fruit mass and enhanced fruit quality.
History
Degree Type
- Master of Science
Department
- Horticulture
Campus location
- West Lafayette