Characterization of Field Pennycress (Thlaspi arvense L.) Germplasm.

Field Pennycress (Thlaspi arvense L.) is a self-pollinating, winter annual oilseed crop that has potential to serve as a winter cover and biofuel feedstock in conventional agricultural systems. As part of a multifaceted breeding initiative, 42 pennycress accessions of diverse origin were grown in five Minnesota environments in 2014 and 2015 to assess their phenotypic variation. Morphological and yield component traits were measured as well as seed characteristics including oil percentage and fatty acid profile. Mixed effects models were used to estimate best linear unbiased estimates (BLUEs) of the trait values for each of the accessions and were used in subsequent analyses. Significant variation for accession (P < 0.05) was observed in 20 of 24 of the fitted trait models and after adjusting for multiple comparisons using Tukey’s Honest Significant Difference, pairwise differences among accessions were detected in 14 of 24. Averaged over 5 environments, seed yield ranged from 511 – 2013 kg ha^-1, oil content from 28.4 – 35.1 % (dry weight basis) and erucic fatty acid from 31.8 – 39.2 %. Yield component traits including one hundred seed weight and seed yield per stem are positively correlated with total seed yield (Pearson’s correlations of r = 0.37, P < 0.05 and r = 0.73, P < 0.05, respectively). Estimates for broad sense heritability ranged from a minimum of 0.19 for peduncle length and ≥ 0.82 for oil and fatty acid content. The phenotypic variation observed in this germplasm and the superior accessions that were identified will inform our breeding efforts and aid in improving pennycress as a viable crop.