Browsing by Subject "Pennycress"

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    Characterization of Field Pennycress (Thlaspi arvense L.) Germplasm for Use as a Cover Crop and Biofuel Feedstock
    (2017-01) Altendorf, Kayla
    Field pennycress (Thlaspi arvense L.) is a winter annual oilseed crop currently under investigation for use as a feedstock for domestic biofuel production. As an undomesticated species, pennycress has a variety of undesirable traits and the species has seen very limited formal selection or genetic improvement. This research seeks to characterize a collection of 42 wild, winter type accessions for morphological and yield component traits (Chapter 2) as well as seed chemistry traits (Chapter 3). This data will be used to guide the breeding and development of improved germplasm and eventual variety release. The germplasm collection was grown in five unique Minnesota environments in 2013/2014 and 2014/2015. Mixed effects models were used to estimate best linear unbiased estimates (BLUEs) for each of the accessions and traits, which were used in subsequent analyses. Within the morphological traits and yield component traits, relationships between traits were assessed using Pearson’s correlation coefficients and estimates of heritability were calculated for each trait. Hierarchical clustering was used to identify groups of accessions based on similarity of trait values. Significant variation for accession was detected in 13 of the 19 trait models for morphological and yield component traits at P < 0.05, and for 1 of 19 at P < 0.10 (Table 2.7). Pairwise differences after adjusting for multiple comparisons using Tukey’s Honest Significant Difference (HSD) resulted in more than one grouping in 9 of the 13 models in which accession was significant (P < 0.05). For seed chemistry traits, significant variation (P < 0.05) for accession was detected for nine of the ten fatty acids detected and oil percentage. Significant variation was observed for many of the traits evaluated, but to make sizable gains in selection for certain traits, additional genetic variation in the form of mutants and additional collections is required.
  • Thumbnail Image
    Item
    Four Cover Crops Dual-Cropped With Soybean: Agronomics, Income, And Nutrient Uptake Across Minnesota
    (2018-02) Ott, Matthew
    Many agricultural watersheds in Minnesota have toxic levels of phosphorus and nitrogen, much of which originates in agricultural fields that are fallowed from October through May. Autumn-sown winter cover crops can be used to retain these nutrients. Soil NO3-N levels and and quantities of N sequestered by winter rye (Secale cereale), Tillage Radish® (Raphanus sativus), and the oilseed crops, winter camelina (Camelina sativa), and pennycress (Thlaspi arvense) were evaluated in a relayed cover crop/soybean production system at three sites spanning the north-south climatic gradient of Minnesota. Tillage Radish® sequestered the most N in autumn, but winter-killed and had high soil NO3-N levels in spring. Winter rye was terminated chemically by early May at each site, whereas the oilseed crops were allowed to grow into June to full maturity and their seeds were harvested. In autumn through early May, winter camelina and pennycress sequestered about 25% less N than winter rye. However, they often sequestered ≥ 2.5 times more N than winter rye when compared at maximum seasonal biomass (up to 130 kg N ha-1), with some of this N coming from spring fertilizer application. The relative amount of applied N captured by oilseeds, defined here as applied N sequestration efficiency, was 95% and 68% for winter camelina and pennycress, respectively. Winter camelina yields ranged from 600 to 1100 kg ha-1, while pennycress yields ranged from 900 kg ha-1 to 1550 kg ha-1. When combined with yields of relay-cropped soybean, net income for relay-crop systems was generally equivalent to mono-cropped soybean.
  • Thumbnail Image
    Item
    Genomics and domestication of Field Pennycress (Thlaspi arvense)
    (2015-05) Dorn, Kevin
    Thlaspi arvense (field pennycress) is a cold tolerant oilseed species that is being domesticated as a new rapid cycling, winter annual cover crop and feedstock for biodiesel production. Pennycress is related to Arabidopsis thaliana, a model species that has provided an in-depth understanding of many basic developmental and physiological plant processes, which will provide vital information for the rapid domestication of a wild species into a new crop. By targeting key pennycress traits for improvement, such as reducing seed dormancy, increasing rates of spring flowering and maturity, increasing yield, and modifying seed oil composition, we are poised to develop a new winter cash crop that can fit within the corn/soybean rotation. To enable a mutation breeding approach that utilizes the massive amount of Arabidopsis-based knowledge, genomic resources are needed to identify target genes believed to influence key traits. In this dissertation, the first comprehensive annotated transcriptome assembly and comparative analyses are presented, along with the first draft genome sequence for pennycress. In these analyses, target assembled transcripts and corresponding DNA sequences are identified and compared to Arabidopsis homologs and enable the forward and reverse genetic screening of large scale mutant populations. An analysis of winter and spring annual pennycress accessions is also presented, which identified several wild alleles of the pennycress FLOWERING LOCUS C homolog which was found to be responsible for differentiating between spring and winter annual phenotypes. The resources presented herein will provide an unprecedented set of tools to enable the rapid domestication of a new crop species.
  • Thumbnail Image
    Item
    Understanding and engineering the molecular regulation of nectar production in field pennycress (Thlaspi arvense).
    (2020-09) Thomas, Jason
    Anthropogenic climate change and the growing world population are putting pressure on our agroecosystems. Sustainable farming efforts are needed when intensive agriculture systems are fallow and prone to erosion and nutrient leaching. We can mitigate these issues while increasing farmer income by planting field pennycress (Thlaspi arvense). Pennycress forms penny shaped pods containing oil-rich seeds with diverse uses from jet fuel to cooking oil. As an overwintering cover crop, pennycress grows from fall to late spring, avoiding land-use competition with summer annual cash crops. Pennycress provides an ecosystem service to pollinator populations, which are needed for fruit and vegetable production. Pollinators are suffering due partially to losses of habitat and floral resources. Fortunately, pennycress flowers provide nectar as a floral resource when most agricultural landscapes are barren. Additionally, pollinator visitation increases pennycress seed yield. Therefore, the purpose of the study was to understand the genetics behind nectar production and develop pennycress plants with altered floral traits. Microscopy was performed on pennycress flowers to characterize the structure of the nectar-producing glands called nectaries. Additionally, pennycress nectary transcriptomes were determined using transcriptomic sequencing which led to the identification of genes and metabolic pathways. In both cases, the strong similarity in nectar production was confirmed between pennycress and Arabidopsis thaliana, a model plant and close pennycress relative. Because of the close relationship, it was possible to characterize Arabidopsis genes that can later be used to find orthologs in pennycress. The Arabidopsis gene At5g60760 annotated as ‘a P-LOOP containing nucleoside triphosphate hydrolases superfamily protein’ (hereafter AT5G60760) is a putative inositol kinase highly expressed in nectaries. Through assaying mutant AT5G60760 gene expression and nectar production, it was determined that AT5G60760 negatively regulates nectar production. By using findings from nectary genetics, such as the function of AT5G60760 and the pennycress nectary transcriptome, 13 genes were mutated using CRISPR/Cas9 to alter traits relating to pollinator attraction in field pennycress. We have identified two homozygous mutant lines and conducted phenotyping. The auxin response factor 8 (arf8) mutant flowers and petals are larger and produce more nectar than wild type. The cell wall invertase 4 (cwinv4) mutants do not produce nectar and have greatly reduced invertase activity in nectaries. In the future, these plants can be grown in field settings to test pollinator attraction, assay pollinator health, and measure pennycress seed yield.