Genetic Variation Among and Within Populations in Swedish Species of Sorbus aucuparia L. and Prunus padus L. Assessed in a Nursery Trial

Abstract

Seedlings originating from open-pollinated offspring of six and four populations of Prunus padus and Sorbus aucuparia, respectively, were studied with respect to phenology and growth traits for 3-4 years in a nursery. There were no replications at the population levels since the experiments should be converted to seedling seed orchards. Therefore, a special statistical model for analysis of the population effect was developed making use of neighbour performances. This model was also used for derivation of heritabilities. The heritabilities for phenology traits were in many cases high in P. padus, > 0.40, while they varied in the range 0.07-0.62 in S. aucuparia. The population effect was significant for all growth rhythm traits in P. padus and for a majority of traits in S. aucuparia. In both species the heritability for height decreased over time. Only bud flushing in P. padus indicated a relationship with population latitudinal origin in some cases. The genetic correlations between bud flushing different years were relatively strong in both species while the corresponding correlations for leaf colouring were moderate in P. padus and weak in S. aucuparia. In conclusion, the observed structure suggests that the pattern of seed dispersal may have an influence on the among- and within-population variation.

Variation de la résistance au gel au printemps et en automne entre et dans les populations espagnoles sauvages de Castanea sativa

“…In general, data corresponding to the two highest temperatures (-7 and -10 • C) were used in the spring test, while data corresponding to the two intermediate temperatures (-10 and -12 • C) were used in the autumn test. For the field variables, we used score data recorded on a single day, selecting the date with the maximum coefficient of variation (Baliuckas et al, 1999;Jermstad et al, 2001).…”

Geographic differentiation in adaptive traits of wild chestnut Spanish populations (Castanea sativa Miller)

“…Differences between genetic entries for flushing time were studied using different types of variables, being the analysis of single date scores one of them. This is a cheap method that allows an efficient detection of differences between genetic entries if records are taken when 50% of the trees have flushed (Baliuckas et al, 1999;Jermstad et al, 2001). In this experiment, raw flushing scores were used for the analysis of each date data, while for the joint analysis of years and sites standardised data were used to remove the effect of different means and variances across years and sites.…”

Genecology of 20 paper birch (Betula papyrifera Marsh.) provenances from British Columbia and northern Idaho.

“…Such variations have also been observed between co-occurring species growing on the same site (Lechowicz 1984). The simplest explanation for the observed variation in these characteristics is that it evolved as a measure to avoid unfavourable conditions (Kramer 1995) and involves a trade-off between maximizing growing season length and protection against the potential damaging effects of early and late season frosts (Vaartaja 1959;Nienstaedt 1974;Lechowicz 1984;Cannell and Smith 1986;Hanninen 1991;Kramer 1995;Baliuckas et al 1999). Lechowicz (1984) suggests three other broad possible explanations for the observed variation in leaf phenology between species: phylogenetic, historical and adaptive.…”

“…Intraspecific variations in phenological characteristics, such as bud flush and leaf drop, are known to be under genetic control (Lechowicz 1984) and are highly adaptive (Vaartaja 1959;Lechowicz 1984;Kramer 1995;Baliuckas et al 1999). Such variations have also been observed between co-occurring species growing on the same site (Lechowicz 1984).…”