Abstract Detail

Crops and Wild Relatives

Mason, Chase [1], Bahmani, Keivan [1], Giguere, Madlyn [1], Dowell, Jordan [1].

Examining volatile terpenoid diversity in cultivated sunflower vegetative and reproductive tissues.

Domestication has often been reported to reduce crop plant genetic and phenotypic diversity in relation to wild progenitors. Here we estimate the degree of phytochemical diversity present in the breeding germplasm of cultivated sunflower (Helianthus annuus), with a focus on volatile terpenoids. Terpenoids are known to mediate a wide range of biotic interactions, from serving as chemical defenses against herbivory to pollinator attractants in flowers. Using twelve inbred lines previously reported to represent roughly half of the allelic diversity present in the American USDA and French INRA germplasm repositories, solid-phase microextraction gas chromatography-mass spectrometry was performed on leaf, bract, petal, and disc floret samples of each genotype grown under common high-resource conditions. Several hundred volatile compounds were detected, with a small subset of compounds detected in all samples of a given tissue type. Variation in total terpenoid abundance was large, and the balance between monoterpenes and sesquiterpenes varied from nearly entirely monoterpenes to a substantial portion of sesquiterpenes. This terpenoid diversity is comparable to that detected in wild Helianthus annuus among populations across its large native range, though far smaller than the diversity of terpenoid profiles present across the genus Helianthus as a whole. This indicates that while the cultivated sunflower primary and secondary germplasm likely has genetic variation that can be mined for the improvement of biotic interactions in crop varieties, the tertiary germplasm represents a far more diverse pool of genetic resources. Leveraging variation in terpenoid production to improve herbivore and pathogen defense, microbial mutualisms, and pollinator visitation are potential routes to cultivar improvement for more sustainable oilseed production.

Related Links:
Mason Lab website

1 -
2 - University Of Central Florida, Biological Sciences, 4110 Libra Dr, Orlando, FL, 32816, United States
3 - University of Central Florida, Department of Biology, 4110 Libra Drive, Orlando, FL, 32816, USA
4 - University of California, Davis, Department of Plant Sciences, One Shields Ave, Davis, CA, 95616, USA

Keywords:
sunflower
terpenoid
phytochemistry
domestication
Diversity
biosynthesis
chemical defense
monoterpene
sesquiterpene
phenotypic integration
leaf
flower
GC-MS.

Presentation Type: Oral Paper
Number: CWR1013
Abstract ID:292
Candidate for Awards:None