Showing papers by "Krystyna Klimaszewska published in 2018"

Somatic Embryogenesis and Plant Regeneration From Primordial Shoot Explants of Picea abies (L.) H. Karst. Somatic Trees.

Abstract: The recalcitrance of adult conifer tissues has prevented vegetative propagation of trees with known and desired characteristics. Somatic embryogenesis (SE) initiation protocol, recently developed for white spruce (Picea glauca, Klimaszewska et al., 2011), was applied in order to examine the feasibility, frequency and timing of SE induction from primordial shoots (PS) of Norway spruce (P. abies). In total, 39 genotypes were screened from 2015 to 2017 using 4-6 years old trees of SE origin as explant donors. Two genotypes responded: 11Pa3794 produced six proliferating embryonal mass (EM) sublines and 11Pa4066 produced 23 EM sublines. SE initiations occurred at the beginning of April, when the temperature sum (d.d.) started to accumulate, and at the end of October or beginning of November when the chilling unit (ch.u.) sum was over 500. EM sublines from both genotypes contained numerous early somatic embryos as detected by acetocarmine staining. The sublines of 11Pa4066 produced the mean of 78.6 ± 12.8 cotyledonary somatic embryos /g FW, but 11Pa3794 produced only a few cotyledonary somatic embryos that were able to germinate. The original EM lines (from which the trees were regenerated) had produced the same number of somatic embryos in 2011 maturations, which was approximately 120 somatic embryos /g FW. Microsatellite analyses conducted with both responsive genotypes confirmed the genetic stability of the EM sublines compared with the donor trees growing in the field. SE protocol developed for white spruce PS explants was also suitable for PS of Norway spruce if the explants were in the responsive developmental stage.

Root growth of somatic plants of hybrid Pinus strobus (L.) and P. wallichiana (A. B. Jacks.) is affected by the nitrogen composition of the somatic embryo germination medium

Abstract: This paper describes improvement in root growth of hybrid white pine somatic plants on a somatic embryo germination medium containing solely organic nitrogen sources. Mature somatic embryos of F2 hybrid Pinus strobus × Pinus wallichiana backcrossed with P. strobus converted to plants but survival of the somatic plants was not satisfactory prompting the present study on somatic seedling root growth on germination media varying in nitrogen (N) composition. The media were modifications of Litvay’s (Litvay et al. in Plant Cell Rep 4:325–328, 1985) which included two main groups: G1, G2, G3, G4 all contained inorganic N with or without glutamine (Gln) or casein hydrolysate (CH) and G5, G6, G7 contained solely glutamine and/or CH. In addition, G8 was half-strength G1 (with organic N) and G9 was half-strength CD (Campbell and Durzan in Can J Bot 53:1652–1657, 1975) without organic N. The roots of plants growing on media containing solely organic N grew about 2.55 times longer than on those containing solely inorganic N or both inorganic and organic N. The longest roots grew on G7 supplemented with CH and on G5 with both CH and Gln. Microarray analysis of somatic plants germinated on G1 versus G7 revealed that depending on the N source the somatic plants displayed changes in the transcriptome resulting in the differential expression of a range of genes involved in essential processes for plant growth and development. Roots grown in the absence of inorganic N were capable of rapid uptake of labelled inorganic 15N during the 2 h incubation in the nutrient solution. The somatic plants from G5 medium acclimatized at the rate twice as high as those from G1 (with both inorganic and organic N) and G2 (solely inorganic N) under standard fertilization regime.