Between Dec 19, 2024 and Jan 2, 2025, datasets can be submitted to DRUM but will not be processed until after the break. Staff will not be available to answer email during this period, and will not be able to provide DOIs until after Jan 2. If you are in need of a DOI during this period, consider Dryad or OpenICPSR. Submission responses to the UDC may also be delayed during this time.

Browsing by Author "Tandukar, Zenith"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Towards positional cloning and functional analysis of genes that control wax production in barley
    (2018-09) Tandukar, Zenith
    Epicuticular waxes are the first point of contact between plants and their external environment, and provide mechanical and physiological support to plants. The leaf sheath and spike waxes of barley are rich in beta-diketone and hydroxy-beta-diketones that gives barley waxes a pronounced thread-like and fibrous morphology. Two previously described mutants are the subjects of this study namely: glossy sheath 2 (gsh2) and Glossy spike (Cer-yy). Both mutants exhibit a glossy (lack of epicuticular waxes) phenotype on the spike, while the gsh2 mutant also exhibits a glossy phenotype on the leaf sheaths on upper leaves. In this study, the gsh2 and Cer-yy mutants were exploited (1) to gain an increased understanding of the developmental timing and tissue specificity of wax accumulation; (2) to determine if gsh2 and/or Cer-yy mutants impact water retention; and (3) to fine map and identify candidate genes for GSH2 and CER-YY. Compared to wildtype, both mutants exhibited an absence of thread-like and fibrous waxes in the upper leaf sheaths and spikes, but an increased presence of plate-like lobed waxes following the elongation of the third internode. No significant differences in whole plant transpiration rates were observed between Bowman-gsh2, Bowman-Cer-yy and cv. Bowman in either high and low vapor pressure deficit conditions. Fine mapping populations segregating for GSH2 and CER-YY reduced the regions containing GSH2 to ~600Kbp and CER-YY to ~1.2 Mbp. Each region contains multiple candidate genes based on their functional annotation that warrant further research to isolate the respective causative genes.
  • Thumbnail Image
    Item
    Understanding the genetic architecture of secondary domestication traits in Field Pennycress (Thlaspi arvense L.)
    (2022-12) Tandukar, Zenith
    Thlaspi arvense L. (Field Pennycress) is a newly domesticated winter annual oilseed capable of improving ecosystems and intensifying agricultural productivity without new land displacement. Pennycress is a winter hardy cover crop that provides ecosystem services such as reduced soil erosion and nutrient loss in between fall corn harvest and spring soybean planting. However, pennycress is currently limited by its small seed size and unimproved oil production. This dissertation builds on the limited research on pennycress breeding and genetics and aims to establish and characterize a global diversity panel of wild pennycress accessions, two biparental recombinant inbred populations, and three independent EMS-derived mutants to contribute knowledge and resources to understand important seed and agronomic characteristic traits in pennycress. Chapter 1 presents a literature review focused on the status of pennycress breeding and genetics, as well as factors that may shed light to understanding the genetic and physiological control of seed size and oil content. Chapter 2 presents a genetic dissection of seed size, oil content, and protein content via genome-wide association studies in a diversity panel. Chapter 3 explores and characterizes the phenotypic and genotypic diversity in two recombinant inbred populations developed for field pennycress, whereas chapter 4 reports the characterization of three independent wax mutants in pennycress and the implications of waxes on total seed oil content in pennycress.