Genetic parameters of growth and adaptive traits in aspen (Populus tremuloides): Implications for tree breeding in a warming world

Abstract

Aspen (Populus tremuloides Michx) is a widespread commercial forest tree of high economic importance in western Canada and has been subject to tree improvement efforts over the past two decades. Such improvement programs rely on accurate estimates of the genetic gain in growth traits and correlated response in adaptive traits that are important for forest health. Here, we estimated genetic parameters in 10 progeny trials containing >30,000 trees with pedigree structures based on a partial factorial mating design that includes 60 half-sibs, 100 full-sib families and 1,400 clonally replicated genotypes. Estimated narrow-sense and broad-sense heritabilities were low for height and diameter (~0.2), but moderate for the dates of budbreak and leaf senescence (~0.4). Furthermore, estimated genetic correlations between growth and phenology were moderate to strong with tall trees being associated with early budbreak (r = -0.3) and late leaf senescence (r = -0.7). Survival was not compromised, but was positively associated with early budbreak or late leaf senescence, indicating that utilizing the growing season was more important for survival and growth than avoiding early fall or late spring frosts. These result suggests that populations are adapted to colder climate conditions and lag behind environmental conditions to which they are optimally adapted due to substantial climate warming observed over the last several decades for the study area. OPEN ACCESSCitation: Ding C, Hamann A, Yang R-C, Brouard JS (2020) Genetic parameters of growth and adaptive traits in aspen (Populus tremuloides): Implications for tree breeding in a warming world. PLoS ONE 15 (3): e0229225. https://doi.org/10.

Variation and Genetic Parameters of Leaf Morphological Traits of Eight Families from Populus simonii × P. nigra

“…The Best Linear Unbiased Prediction (BLUP) method [55,56] can predict the value of random effects, effectively reduce the error variance of prediction breeding value, improve the accuracy of selection and make it possible to predict the breeding value of different generations of individuals. An accurate BLUP prediction value and forward selection based on an individual breeding value will improve the selection efficiency and genetic gain in the process of genetic improvement [57,58]. With the rapid development of genomics in recent years, the combination of genomics and quantitative genetics has a significant impact on the genetic gain of traits.…”

Achievements and Challenges of Genomics-Assisted Breeding in Forest Trees: From Marker-Assisted Selection to Genome Editing

“…The genetic merit is predicted according to the degree of kinship between the trees of a breeding population under the assumption that individuals with a common ancestor are phenotypically similar and share loci of interest. However, conventional breeding has allowed significant genetic gains in different forest species [ 4 , 49 , 64 ], even when it presents clear disadvantages, such as the long generation time required to complete a breeding cycle [ 10 , 65 ]. The advent of molecular marker technology, in combination with traditional phenotypic selection, has led to the development of marker-assisted selection (MAS) [ 10 ].…”

“…Therefore, a QTL that is not in complete LD with an individual marker may be in complete LD with a specific haplotype. Moreover, haplotype-based approaches can include epistatic effects, in addition to additive effects [ 208 , 209 ], which is of interest in forest tree breeding (for example, in clonal selection and in the dissection of adaptive traits [ 4 , 210 ]. Additionally, the use of haplotypes, instead of individual markers, reduces the degrees of freedom in the prediction or genomic-association models, which contributes to greater accuracy in the detection of QTLs [ 192 ].…”

“…In this sense, important efforts in forest tree breeding have been carried out to improve traits of economic interest, to select trees (or hybrids) adapted to new habitats, or to generate trees that are more tolerant to various biotic and abiotic stresses. From the point of view of wood productivity, conventional breeding programs have continuously been improving traits related to throughput, such as wood volume, tree height, diameter at breast height, stem straightness, survival and wood quality, under various environmental conditions [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ].…”

Variation in Seed Germination and Seedling Growth in Five Populations of <i>Vitellaria paradoxa</i> C.F. Gaertn. Subsp. <i>Nilotica</i> in Uganda

“…The genetic effects on the seedlings could have been inherited due to the narrow sense heredity which is important for shea tree breeding (improvement). Related studies [14] recommended selection of Populus tremuloides genotypes with taller heights and larger diameter growth for the species improvement. Meanwhile it can also be noted that environment can greatly affect growth performance in species, however this is not additive and therefore can change with changing environment.…”