2017 journal article

Variation among Loblolly Pine Seed Sources across Diverse Environments in the Southeastern United States

FOREST SCIENCE, 63(1), 39–48.

By: A. Farjat*, A. Chamblee, F. Isik*, R. Whetten* & S. McKeand*

author keywords: Pinus taeda; seed source; provenance test; genotype x environment interaction; multienvironmental trial analysis
Source: Web Of Science
Added: August 6, 2018

Seven seed sources of first-generation plantation selections of loblolly pine (Pinus taeda L.) were evaluated for six traits in test sites across most of its native range east of the Mississippi River in the southeastern United States. The traits evaluated were survival, height, volume, straightness, stem forking, and incidence of fusiform rust disease (caused by Cronartium quercuum [Berk.] Miyabe ex Shirai f. sp. fusiforme). At age 8 years, survival was high, with most seed sources having survival greater than 75% at all but two test sites. South Carolina Coastal and Georgia-Florida Coastal seed sources exhibited the fastest growth and most resistance to fusiform rust, whereas the Virginia seed source exhibited the slowest growth but had the best stem form. Test sites and seed source were significantly different for all traits. Seed source × site interactions (genotype × environment [G × E]) were also significant for all traits except stem forking. Low type B genetic correlation values (rB <0.67) for height, volume, and straightness suggest the presence of G × E interactions. The South Carolina Coastal and Virginia seed sources contributed disproportionally the most to G × E interactions for growth traits, but environmental contributions to G × E interactions were distributed relatively uniformly across most test sites. The results indicate that when seed sources are moved outside of their adaptive range, important G × E interactions should be expected and the difference among seed sources originating from a wide range of climates are expected to be more pronounced in older ages.