Genetic basis of temporal variation in phenology in a woody perennial plant
摘要
The form of phenotypic plasticity in traits that are repeatedly and potentially reversibly expressed multiple times throughout an individual’s lifetime is labile plasticity. Yet, little is known about selection on, and genetic variation and inheritance in, such plasticity. Herein I embedded dynamic growth phenology traits into empirical understanding of the variability, inheritance, and predictability of their labile plasticity using a Populus common-garden experiment. I found no single nucleotide polymorphisms (SNPs) peak associated at P < 1e−4 with labile plasticity in phenological traits, overlapping in its two populations and no such plasticity-associated SNPs identified across study traits in single populations. Higher plasticity and more plasticity SNPs were identified in the population from climatically harsher conditions. While 6% of phenology peak-associated SNPs underwent adaptive selection, 95% of the identified plasticity SNPs were also peak associated with a given phenology, but none of them were found under selection. Plasticity SNP-containing genes highlighted environmental responsiveness functions for phenology plasticity. Projections for labile plasticity in phenology consistently showed that plasticity or trait peak-associated SNPs generated a higher predictive accuracy than non-associative counterparts. Altogether, the study elucidates the idiosyncratic characteristics of labile plasticity in growth phenology and deepens our understanding of its genetic modulation and evolution.