The use of digital morphometrics and spring phenology for clone recognition in trembling aspen (populus tremuloides michx.) and its comparison to microsatellite markers
- 239 Downloads
Aspen clones were traditionally identified based on similarities in several phenotypic traits including leaf shape. This required several visits of the stands, laborious measurements and subjective visual assessments. In this study, we investigated a novel approach to clone identification using digital morphometrics of leaf shape complemented with bark characteristics and spring phenology. Aspen clones were delineated based on molecular (microsatellite loci), morphological (leaf shape, bark colour and type) and phenological (when first fully expanded leaves appeared) characteristics. Leaves were scanned and images were analyzed using normalized elliptic Fourier descriptors and principal component analysis. Using microsatellite loci, 18 clones were identified among 60 aspen trees in three sites investigated in this study. When employing digital morphometrics, foliar types in two out of the three sites matched the clones defined by microsatellite markers. Many ramets from the third site were clustered erroneously into incorrect clones. The reclassification test indicated that leaf shape contains features according to which very similar clones can be differentiated with low error rates. However, because it was not possible to set a threshold for maximum distances within clones, application of digital morphometrics of complex leaf shape for clone identification in natural aspen stands with a high number of multi-ramet clones and many singletons is unfeasible. We judged spring phenology as the least reliable trait for clone recognition and suggested possible causes of heterogeneous leaf flushing among ramets of the same genotype.
KeywordsPopulus tremuloides Clone identification Leaf flush Environmental effect Morphometrics Ramet Foliar diversity Spring phenology Microsatellite markers Clonal integration
We thank to everybody who has participated in this project namely M. Baret, E. Whitfield, and C. Pack. This work was supported by the Centre for Forest Research, National Science and Engineering Research Council, Industrial Chair NSERC-UQAT-UQAM in Sustainable Forest Management, Fonds de recherche sur la nature et les technologies, and the government of Quebec.
- Barnes BV (1969) Natural variation and delineation of clonesof Populus tremuloides and P. grandidentata in northern lower Michigan. Silvae Genetica 18:130–142Google Scholar
- Furuta N, Ninomiya S, Takahashi N, Ohmori H, Ukai Y (1995) Quantitative-evaluation of soybean (Glycine-max L MERR) leaflet shape by principal component scores based on elliptic Fourier descriptor. Breed Sci 45:315–320Google Scholar
- Gom LA, Rood SB (1999) The discrimination of cottonwood clones in a mature grove along the Oldman River in southern Alberta. Can J Bot 77:1084–1094Google Scholar
- Jensen RJ, Schwoyer M, Crawford DJ, Stuessy TF, Anderson GJ, Baeza CM, Ruiz O, Ruiz E (2002b) Patterns of morphological and genetic variation among populations of Myrceugenia fernandeziana (Myrtaceae) on Masatierra island: implications for conservation. Syst Bot 27:534–547Google Scholar
- Kemperman J, Barnes B. (1976) Clone size in American aspens. Can J Bot. 2603–2607Google Scholar
- Lexer C, Joseph J, van Loo M, Prenner G, Heinze B, Chase W, Kirkup D (2009) The use of digital image-based morphometrics to study the phenotypic mosaic in taxa with porous genomes. Taxon 58:349–364Google Scholar
- Lopez-de-Heredia U, Sierra-de-Grado R, Cristobal MD, Martinez-Zurimendi P, Pando V, Martin MT (2004) A comparison of isozyme and morphological markers to assess the within population variation in small populations of European aspen (Populus tremula L.) in Spain. Silvae Genetica 53:227–233Google Scholar
- Mancuso S (1999) Elliptic Fourier Analysis (EFA) and Artificial Neural Networks (ANNs) for the identification of grapevine (Vitis vinifera L.) genotypes. Vitis 38:73–77Google Scholar
- Torres MAJ, Demayo CG, Siar SV (2008) Elliptic Fourier analysis of leaf outline differences between and among sixteen species of Hoya. Philipp Agric Sci 91:18–28Google Scholar