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 Subject "Germplasm"

Now showing 1 - 2 of 2
  • 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
    Development of a multiparent population for genetic mapping and allele discovery in six-row barley
    (2018-05) Ollhoff, Alexandrea
    Germplasm collections hold valuable allelic diversity for crop improvement and genetic mapping of complex traits. To gain access to the genetic diversity within the USDA National Small Grain Collection (NSGC), we developed the Barley Recombinant Inbred Diverse Germplasm Population (BRIDG6), a six-row spring barley multi-parent population (MPP) with 88 cultivated accessions ranging from landraces to cultivars crossed to a common parent (Rasmusson). The parents were randomly selected from a core subset of the NSGC that represents the genetic diversity of landrace and breeding accessions. In total, we generated 6,160 F5 recombinant inbred lines (RILs) with an average of 69 and a range of 37-168 RILs per family that were genotyped with 7,773 SNPs. The number of segregating SNPs per family range from 956 to 6,775, with an average of 3,889 SNPs per family. Using BRIDG6, we detected 23 QTL contributing to flowering time. Five QTL were within five megabase pairs of previously described flowering time genes. For the major QTL detected near HvPpd-H1, a flowering time gene that affects photoperiod, both positive and negative allele effects were observed ranging from +4 to –3 days relative to Rasmusson among the 79 families segregating for the SNP. Haplotype-based analysis of HvPpd-H1 identified private alleles to families of Asian origin conferring both positive and negative effects, providing the first observation of flowering time-related alleles private to Asian accessions. We evaluate several subsampling strategies to determine their effect on the power of QTL detection and found that for flowering time in barley, a sample size larger than 50 families or 3,000 individuals results in the highest power for QTL detection. This MPP will be useful for uncovering large and small effect QTL for traits of interest and identifying and utilizing valuable alleles from the NSGC for barley improvement.