Inbreeding Depression in the Full-sib Offspring of Populus nigra L.

Abstract

Controlled pollination was carried out in the species Populus nigra L. in a greenhouse on isolated branches between sisters and a brother - inbreeding (S x B). Female trees (sisters) were also exposed to open pollination (OP) in the neighbourhood of a male tree (brother) and other Populus nigra trees in the vicinity. The analysis of 11 microsatellites was done in the offspring from the inbreeding (S x B) and from the OP. In OP offspring was found 20-76% of viable individuals that were coming from pollination with brother’s pollen (spontaneous inbreeding). These individuals were separated from the offspring. In a randomised field trial the offspring were evaluated for two years. Fitness decreased in S x B offspring, traits of plant height, trunk diameter, height increment and resistance to Melampsora larici-populina Kleb. were lower in comparison with those of OP offspring. A coefficient of inbreeding depression (δ) ranged from 0.373 to 0.034. The significance of differences between the offspring from S x B and OP of the particular sisters was proved. About 30% of homozygous microsatellite loci were identified in inbred S x B offspring, which was more than in OP offspring. This difference was significant in the offspring of three sisters; it was not significant in the offspring of one sister. This trend corresponded to the results of growth traits.

Sex expression and inbreeding depression in progeny derived from an extraordinary hermaphrodite of Salix subfragilis

“…According to a meta-analysis of inbreeding depression in various fitness components, the magnitude of inbreeding depression was highest in growth (plant biomass), lowest in fertility (pollen and ovule traits) and intermediate in survival (Angeloni et al, 2011 ), which is consistent with our results. Inbreeding depression in progeny of Populus nigra derived from full-sib crosses, which is expected to be lower than that in selfed progeny of S. subfragilis , was measured in the height and diameter of stems of 2- and 3-year-old progeny (Benetka et al, 2008 ). The magnitudes of inbreeding depression were from 0.046 to 0.112 in the stem height and from 0.209 to 0.395 in the stem cross-sectional area in P. nigra , nearly half δ m in S. subfragilis (Table 4 ).…”

Aspects of sexual reproduction in rare monoecious Populus nigra var. nigra trees

“…nigra trees was determined in the stand that is located in the grounds of the Silva Tarouca Research Institute for Landscape and Ornamental Gardening, in Central Bohemia (50°00'N, 14°33'E and 306 a.s.l) ( Table 1). The stand was established using 1-yearold seedlings, derived from both controlled and open pollination of relatives of three female trees (BENETKA et al, 2008), in the spring of 2003. Plant spacing was 0.45 ϫ 2 m.…”