Phytochemical diversity and genetics of purple corn

Chatham, Laura A.

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https://hdl.handle.net/2142/105919 Copy

Description

Title

Phytochemical diversity and genetics of purple corn

Author(s)

Chatham, Laura A.

Issue Date

2019-07-10

Director of Research (if dissertation) or Advisor (if thesis)

Juvik, John A.

Doctoral Committee Chair(s)

Juvik, John A.

Committee Member(s)

• Studer, Anthony
• Brown, Patrick J.
• Sacks, Erik
• West, Leslie

Department of Study

Crop Sciences

Discipline

Crop Sciences

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

Anthocyanins, Purple Corn

Abstract

Color strongly influences the perception of food and beverage quality and plays an important role in the marketing, desirability, and consumption of food and beverage products. Increasing demand for more natural products has spurred interest in natural colorants, especially from sources rich in anthocyanins, red to purple plant pigments. Anthocyanin-rich purple corn is being explored as a potential economical source of natural colorant. Our recent survey of colored corn maize germplasm identified a purple corn landrace, Apache Red (AR), with great pigment variability and intensity. Further breeding and investigation of this line resulted in the identification of AR lines with mostly pelargonidin-derived anthocyanins (orange-red) as opposed to the traditional cyanidin-dominant (red-pink) anthocyanin content of other available purple corn varieties. This unique anthocyanin profile may be attractive to the food and beverage industry looking for orange or red natural colorants. Examination of AR lines also resulted in the identification of new flavanol-anthocyanin condensed pigments not previously reported in maize. Further analysis of AR phytochemistry identified abundant apigenin-derived flavones that were found to copigment with anthocyanins, resulting in darker and bluer extracts and improved anthocyanin stability in a model beverage. Given the unique phytochemical diversity present in AR, a large-scale AR mapping population was created and genotyped using genotyping-by-sequencing, and phenotyped for flavonoid content using HPLC. GWAS (genome-wide association studies) revealed several candidate genes associated with anthocyanin concentration and type as well as flux through the flavonoid pathway. Of interest were candidates found for an O-methyltransferase involved in peonidin biosynthesis, an anthocyanidin reductase (ANR) associated with flavonol synthesis, and MATE transporters that may function in more efficient vacuolar sequestration of acylated anthocyanins. In addition to GWAS, GS was used to predict anthocyanin content in AR. Five-fold cross validation resulted in high prediction accuracies, suggesting GS will be useful in landrace development and may be useful for other purple corn breeding programs. Results from these studies have helped inform breeding goals and provide a foundation for future research into anthocyanin and flavonoid biosynthesis in maize pericarp.

Graduation Semester

2019-08

Type of Resource

text

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http://hdl.handle.net/2142/105919

Copyright and License Information

Copyright 2019 Laura Chatham

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