Project description:The genes induced by mechanical stimuli may be also involved in disease resistance and wood formation and development in Acacia koa. If so, mechanically stressed A. koa may be used as a model to study disease resistance and wood formation and development. Microarray analysis was performed to determine expression levels of 4,000 genes related to disease resistance and wood development in Acacia koa in response to mechanical stimuli (touch). RNA was extracted from two groups of A. koa seedlings, (1) mechanically stressed and (2) unstressed koa seedlings. Each group had two biological replicates (n=2), where n represents pools of approcimately 20 individuals.
Project description:The genes induced by mechanical stimuli may be also involved in disease resistance and wood formation and development in Acacia koa. If so, mechanically stressed A. koa may be used as a model to study disease resistance and wood formation and development. Microarray analysis was performed to determine expression levels of 4,000 genes related to disease resistance and wood development in Acacia koa in response to mechanical stimuli (touch).
Project description:Identifying and quantifying the importance of environmental variables in structuring population genetic variation can help inform management decisions for conservation, restoration, or reforestation purposes, in both current and future environmental conditions. Landscape genomics offers a powerful approach for understanding the environmental factors that currently associate with genetic variation, and given those associations, where populations may be most vulnerable under future environmental change. Here, we applied genotyping by sequencing to generate over 11,000 single nucleotide polymorphisms from 311 trees and then used nonlinear, multivariate environmental association methods to examine spatial genetic structure and its association with environmental variation in an ecologically and economically important tree species endemic to Hawaii, Acacia koa. Admixture and principal components analyses showed that trees from different islands are genetically distinct in general, with the exception of some genotypes that match other islands, likely as the result of recent translocations. Gradient forest and generalized dissimilarity models both revealed a strong association between genetic structure and mean annual rainfall. Utilizing a model for projected future climate on the island of Hawaii, we show that predicted changes in rainfall patterns may result in genetic offset, such that trees no longer may be genetically matched to their environment. These findings indicate that knowledge of current and future rainfall gradients can provide valuable information for the conservation of existing populations and also help refine seed transfer guidelines for reforestation or replanting of koa throughout the state.