2017 ASHS Annual Conference

Pumpkin seeds (Cucurbita pepo L.) are high in oil, protein, total unsaturated fatty acids (TUFA), and provide an important source of nutrition and income globally. In the U.S., the seeds are primarily used in trail mixes with various nuts, seeds, dried fruit and sweets, as well as a source of vegetable oil. The use of pumpkin seed in the snacking and vegetable oil industry in the U.S. is expected to rise as the market for healthy foods and vegetable oil increases. To improve the nutritive value of pumpkin seed through breeding, it is important to assess the phenotypic variation of key seed traits among pumpkin accessions. In the current study, protein, oil, fatty acid composition and seed size traits [weight (SWT), length (SL) and width (SWD)] of 35 C. pepo accessions were determined. Protein content among the accessions ranged from 19.47 to 31.34% with a mean of 24.62%, while as oil content ranged from 29.32 to 48.40% with a mean of 41.84%. Linoleic acid (x̅ = 51.19%) was the major fatty acid in the seed followed by oleic (x̅ = 30.77%), palmitic (x̅ = 9.84%), and stearic (x̅ = 5.63%) acid. Significant (P < 0.05) negative correlations were found between oil and protein content (-0.51), linoleic and oleic acid (-0.96), linoleic and stearic acid (-0.37), and SWT and protein content (-0.39). Conversely, significant positive correlations were found between seed size and oil content (0.56-0.69), seed size and palmitic acid (0.49-0.65), seed size and stearic acid (0.38-0.46), palmitic acid and oil content (0.50), and stearic acid and oil content (0.31). Collectively, this data suggests wide variation in seed nutrition within C. pepo and provides insight into the phenotypic relationship among important seed traits. Several accessions high in oil, protein and TUFA were identified and will be useful in breeding for enhanced pumpkin seed nutrition.