| 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. |
