Root Rot Resistance Locus <i>PaLAR3</i> Is Delivered by Somatic Embryogenesis (SE) Pipeline in Norway Spruce (<i>Picea abies</i> (L.) Karst.)

oleh: Jaanika Edesi, Mikko Tikkinen, Malin Elfstrand, Åke Olson, Saila Varis, Ulrika Egertsdotter, Tuija Aronen

Format: Article
Diterbitkan: MDPI AG 2021-02-01

Deskripsi

Research Highlights: The Norway spruce somatic embryogenesis (SE) pipeline is suitable for multiplication of material with root rot resistance traits. Background and Objectives: <i>Heterobasidion</i> root rot is the economically most severe forest pathogen in Europe, reducing the benefit of planting elite forest material. In this study, the SE-propagation ability of elite Norway spruce material carrying root rot resistance traits was studied. Materials and Methods: We analyzed the presence of the root rot resistance locus <i>PaLAR3B</i> among 80 Finnish progeny-tested Norway spruce plus-trees used for SE-plant production as well as in 241 SE lines (genotypes) derived from them. Seven full-sib families with lines having either AA, AB, or BB genotype for <i>PaLAR3</i> locus were further studied for their SE-plant propagation ability. Results: The results indicate that 47.5% of the studied elite trees carry the <i>PaLAR3B</i> allele (45% are heterozygous and 2.5% homozygous). The resistance allele was present among the SE lines as expected based on Mendelian segregation and did not interfere with somatic embryo production capacity. All embryos from <i>PaLAR3</i> genotypes germinated well and emblings were viable in the end of first growing season. However, in three families, <i>PaLAR3B</i> homo- or heterozygotes had 23.2% to 32.1% lower viability compared to their respective hetero- or <i>PaLAR3A</i> homozygotes. Conclusions: There is no trade-off between root rot resistance locus <i>PaLAR3B</i> and somatic embryo production ability, but the allele may interfere with Norway spruce embling establishment.