Abstract Detail

Genetics

Mickley, James [1], Schlichting, Carl [1].

Variation, heritability, and correlated selection in Phlox petal number.

A majority of Eudicot species, especially within the superclade Pentapetalae are predominantly five-petaled, encompassing a large portion of angiosperm diversity. Many of these species are considered to have fixed for the five-petaled phenotype, yet in some cases low levels of natural variation in petal number have been documented, particularly in the Polemoniaceae. In addition, many floral traits show patterns of phenotypic integration and floral part numbers are known to be correlated, suggesting common genetic controls. Together, these two aspects provide tools for examining the genetic basis of the five-petaled phenotype and may help answer questions as to why or how this phenotype became so common. Phlox drummondii is one such species within the Polemoniaceae that has natural within-individual variation in petal number. Here, I test for a genetic basis underlying this variation by performing artificial selection experiments to increase petal number, decrease petal number, and to decrease variation in petal number, all while simultaneously examining the correlated selection response in sepals, stamens, and carpels. My results show that the direction of petal number variation has a strong genetic component, though variation itself cannot be reduced. Furthermore, several differences exist in the results between selection for 4- and 6-petaled flowers which suggest that gains and losses of petals may not be equivalent and may be under separate control. This work provides insight into the genetics and development of floral petal number, providing a starting point for closer examinations of what factors cause flowers to become five-petaled.

Related Links:
My Website

1 - University of Connecticut, Department of Ecology and Evolutionary Biology, 75 N. Eagleville Road, Unit 3043, Storrs, CT, 06269-3043, United States

Keywords:
merosity
pentamery
floral selection
floral evolution
correlated selection
Phlox
subindividual variation
pentapetalous
Polemoniaceae
petal number
flower petals.

Presentation Type: Oral Paper
Session: 11, Genetics
Location: 105/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 2:30 PM
Number: 11005
Abstract ID:887
Candidate for Awards:Margaret Menzel Award