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theses

Amaranth (Amaranthus spp.) is cultivated in over 80 countries as a preferred leafy green vegetable crop and is often cited as having unrealized potential to reduce multiple micronutrient deficiencies occurring at high rates in the countries where it is cultivated. Despite widespread cultivation and a wealth of genetic resources held by USDA GRIN and international germplasms, amaranth remains designated as an orphan crop due to a lack of development; producers are not often provided with options of cultivars as a leafy green vegetable. The goal of this dissertation research was to narrow the information gap preventing an effective cultivar development platform which serves goals of both farmers and organizations which promote Amaranthus among other indigenous vegetables to reduce prevalence of micronutrient deficiencies. Specific objectives were to: 1) establish breeding priorities to develop breeding lines and cultivars which can meet the needs of farmers and goals of international development goals focusing on orphan crops, 2) screen genetic diversity for traits of interest in entries which can either be utilized as breeding lines or fast-tracked for cultivar development 3) confirm consistency of genotype effect for prioritized traits and observe whether effect of genotype by environment interaction is sufficiently low to successfully select for these traits. Genotype effect on accumulation of Fe content was found to be substantial and consistently significant, with one entry identified which accumulated high-source quantities of Fe across multiple environments including environments in which the mean Fe content across entries to fall well below high-source thresholds. A screening method to verify successful outcrossing events using SSRs was developed to facilitate breeding efforts with this crop which historically has relied on visible markers given the high rate of self-pollination, small, and highly numerous flowers on inflorescences of Amaranthus. The culmination of this study presents a case study of the first characterization of a crop to reliably provide high-source levels of three essential micronutrients which is aligned with the cultural preferences of populations often deficient in those micronutrients where it is cultivated, providing a platform for development of similar commodities toward alleviation of hidden hunger and wide-spread micronutrient deficiencies.

ETD_9337

doi:10.7282/T3QJ7MXB

Ph.D.

Includes bibliographical references

by David Rohan Byrnes

ETD doctoral

The author owns the copyright to this work.