title: Influence of low- and high-elevation plant genomes on the regulation of autumn cold acclimation in Abies sachalinensis.
abstract: Boreal coniferous species with wide geographic distributions show substantial variation in autumn cold acclimation among populations. To determine how this variation is inherited across generations, we conducted a progeny test and examined the development of cold hardening in open-pollinated second-generation (F2) progeny of Abies sachalinensis. The F1 parents had different genetic backgrounds resulting from reciprocal interpopulational crosses between low-elevation (L) and high-elevation (H) populations: L × L, L × H, H × L, and H × H. Paternity analysis of the F2 progeny using molecular genetic markers showed that 91.3% of the fathers were located in surrounding stands of the F1 planting site (i.e., not in the F1 test population). The remaining fathers were assigned to F1 parents of the L × L cross-type. This indicates that the high-elevation genome in the F1 parents was not inherited by the F2 population via pollen flow. The timing of autumn cold acclimation in the F2 progeny depended on the cross-type of the F1 mother. The progeny of H × H mothers showed less damage in freezing tests than the progeny of other cross-types. Statistical modeling supported a linear effect of genome origin. In the best model, variation in freezing damage was explained by the proportion of maternally inherited high-elevation genome. These results suggest that autumn cold acclimation was partly explained by the additive effect of the responsible maternal genome. Thus, the offspring that inherited a greater proportion of the high-elevation genome developed cold hardiness earlier. Genome-based variation in the regulation of autumn cold acclimation matched the local climatic conditions, which may be a key factor in elevation-dependent adaptation.
authors.affiliation: Forestry Research Institute, Hokkaido Research Organization Bibai, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Ishizuka
authors.affiliation: Institute of Low Temperature Science, Hokkaido University Sapporo, Japan.
authors.forename: Kiyomi
authors.initials: K
authors.lastname: Ono
authors.affiliation: Institute of Low Temperature Science, Hokkaido University Sapporo, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Hara
authors.affiliation: Graduate School of Agricultural and Life Sciences, The University of Tokyo Tokyo, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Goto
keywords: Abies sachalinensis; cold acclimation; elavational cline; interpopulation variation; modeling; paternity analysis; phenology