Predominant paternal inheritance pattern of light-energy processing adaptive traits in red and black spruce hybrids

• Published in: Canadian journal of forest research Vol. 37; no. 2; pp. 293 - 305
• Main Authors: Major, J.E, Barsi, D.C, Mosseler, A, Rajora, O.P, Campbell, M
• Format: Journal Article
• Language: English
• Published: Ottawa, ON National Research Council of Canada 01.02.2007; NRC Research Press; Canadian Science Publishing NRC Research Press
• Subjects: adaptation; Adaptation (Physiology); Biological and medical sciences; cold tolerance; crossing; dry matter accumulation; Efficiency; Females; Fluorescence; forest trees; Forestry; Forests; Freezing; Fundamental and applied biological sciences. Psychology; Genetic aspects; Genetic engineering; heritability; Hybridization; Hybridization, Vegetable; Hybrids; light; paternally inherited traits; Photochemicals; Physiological aspects; Picea mariana; Picea rubens; plant growth; radiation use efficiency; Spruce; Studies; traits; Canada; Forestry
• ISSN: 0045-5067; 1208-6037
• DOI: 10.1139/x06-228

Ecophysiological traits related to light-energy processing and freezing tolerance are important adaptive traits in plants. Our goal was to investigate the pattern of inheritance of these traits in hybrids using controlled intra- and inter-specific crosses of red spruce (Picea rubens Sarg.) (RS) and black spruce (Picea mariana (Mill.) BSP) (BS). Our initial working hypothesis was that expected hybrid index categories could be a predictor of adaptive traits. Species results of dark-adapted photochemical efficiency (F(v)/F(m)) and light-adapted light-energy processing traits, quantum yield (YLD), thermal dissipation efficiency (qN), and chlorophyll fluorescence (F(pc)), were consistent with previously published open-pollinated, species provenance results. Initially, YLD, qN, and F(pc), showed an additive inheritance pattern, evident by average hybrid index 50 having a mid-parent value. Because of various crosstypes of the hybrid families, parental analysis, testing male, female, and interaction effects, and having three categories (pure RS, pure BS, and hybrid spruce), revealed significant male and nonsignificant female and interactive effects. Underlying the averaged additive results was a significant species-specific paternal inheritance pattern. Crosses with BS males had 13.7% higher YLD (P = 0.001), 15.4% lower qN (P = 0.008), and 43.0% higher F(pc) (P = 0.096) than crosses with either RS or hybrid males. F(v)/F(m) showed a nonadditive or parental species pattern. Parental analysis of F(v)/F(m) showed significant male, female, and male x female interaction effects, and further analysis supports a largely species-specific and paternally inherited trait. Freezing tolerance revealed a mixed model of inheritance dominated by species effects. Total dry mass was positively correlated with YLD, and negatively correlated with F(v)/F(m) and qN, suggesting a biological tradeoff. We know of no other studies in trees demonstrating paternal inheritance of ecophysiological processes that affect adaptation and fitness.