2015 journal article

Effects of Inbreeding on Growth and Quality Traits in Lob lolly Pine

FOREST SCIENCE, 61(3), 579–585.

By: G. Ford*, S. McKeand*, J. Jett* & F. Isik*

author keywords: inbreeding depression; Pinus taeda; tree improvement; genetic load; breeding strategy
UN Sustainable Development Goal Categories
14. Life Below Water (OpenAlex)
15. Life on Land (Web of Science)
Source: Web Of Science
Added: August 6, 2018

The effect of inbreeding in two provenances of loblolly pine (Pinus taeda L.) was investigated. Ten parent trees from each of the Coastal Plain and Piedmont provenances in the southern United States were mated to produce outcrossed (F = 0), half-sib mated (F = 0.125), full-sib mated (F = 0.25), and selfed (F = 0.5) progeny. Growth and quality traits were measured in the progeny of the four inbreeding levels at age 9. Inbreeding decreased height growth up to 21% and stem volume up to 33% but did not affect stem straightness or fusiform rust disease incidence. As expected from quantitative genetics theory, inbreeding depression was more pronounced in crosses between more closely related individuals. Responses to inbreeding varied within parental groups at each inbreeding level, especially depending on the pollen source. Most of the parent groups showed consistent decreases in vigor with increased inbreeding. However, one specific parent group actually had a positive growth response, demonstrating that such genotypes may be selected for advanced-generation breeding, especially when breeding strategies make use of crosses among related individuals. Variation among inbreeding levels and among parents within inbreeding levels presents opportunities as well as challenges for developing breeding strategies in forest trees.