Variation in seedling freezing response is associated with climate in Larrea.
Variation in seedling freezing response is associated with climate in Larrea.
复制标题
幼苗冷冻反应的变化与拉雷亚的气候有关。
DOI：
10.1007/s00442-011-2181-z
复制
发表时间：
2012
期刊：
影响因子：
2.7
通讯作者：
Pockman,WilliamT
中科院分区：
文献类型：
--
作者：
Medeiros,JulianaS;Marshall,DianeL;Maherali,Hafiz;Pockman,WilliamT
Variation in freezing severity is hypothesized to have influenced the distribution and evolution of the warm desert evergreen genusLarrea. If this hypothesis is correct, performance and survival of species and populations should vary predictably along gradients of freezing severity. If freezing environment changes in the future, the ability ofLarreato adapt will depend on the structure of variation for freezing resistance within populations. To test whether freezing responses vary among and withinLarreapopulations, we grew maternal families of seedlings from high and low latitudeL. divaricataand high latitudeL. tridentatapopulations in a common garden. We measured survival, projected plant area and dark-adapted chlorophyll fluorescence (Fv/Fm) before and after cold acclimation and for 2 weeks following a single freeze. We detected significant variation in freezing resistance among species and populations. Maternal family lines differed significantly in their responses to cold acclimation and/or freezing for two out of the three populations: amongL. tridentatamaternal families and among low latitudeL. divaricatamaternal families. There were no significant differences across maternal families of high latitudeL. divaricata. Our results indicate that increased freezing resistance in high latitude populations likely facilitated historical population expansion of both species into colder climates, but this may have occurred to a greater extent forL. tridentatathan forL. divaricata. Differences in the structure of variation for cold acclimation and freezing responses among populations suggest potential differences in their ability to evolve in response to future changes in freezing severity.
