scholarly journals Root Rot Resistance Locus PaLAR3 Is Delivered by Somatic Embryogenesis (SE) Pipeline in Norway Spruce (Picea abies (L.) Karst.)

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 193 ◽  
Author(s):  
Jaanika Edesi ◽  
Mikko Tikkinen ◽  
Malin Elfstrand ◽  
Åke Olson ◽  
Saila Varis ◽  
...  

Research Highlights: The Norway spruce somatic embryogenesis (SE) pipeline is suitable for multiplication of material with root rot resistance traits. Background and Objectives: Heterobasidion 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 PaLAR3B 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 PaLAR3 locus were further studied for their SE-plant propagation ability. Results: The results indicate that 47.5% of the studied elite trees carry the PaLAR3B 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 PaLAR3 genotypes germinated well and emblings were viable in the end of first growing season. However, in three families, PaLAR3B homo- or heterozygotes had 23.2% to 32.1% lower viability compared to their respective hetero- or PaLAR3A homozygotes. Conclusions: There is no trade-off between root rot resistance locus PaLAR3B and somatic embryo production ability, but the allele may interfere with Norway spruce embling establishment.

2019 ◽  
Vol 49 (12) ◽  
pp. 1604-1612
Author(s):  
Tingyu Sun ◽  
Yanli Wang ◽  
Lihua Zhu ◽  
Xiaoqin Wu ◽  
Jianren Ye

Pine wilt disease (PWD) is a severe threat to pine forests in East Asia. Screening and breeding of resistant varieties is a very effective way to prevent and control PWD; however, no reliable somatic embryogenesis system has yet been developed for the elite nematode-resistant Pinus thunbergii Parl. line. In this study, we studied the plant regeneration via somatic embryogenesis of nematode-resistant P. thunbergii. Initiation of embryogenic tissue was significantly affected by seed family (p = 0.017), immature zygotic embryo stage (p = 0.032), and initiation medium (p = 0.004). Seed family 37 was the most favorable female parent for initiation of P. thunbergii. Furthermore, the initiation rate increased from the pre-embryonic stage to the cleavage polyembryonic stage. The optimal medium was I2, containing 2,4-dichlorophenoxyacetic acid (9 μmol·L−1) and 6-benzyladenine (4.4 μmol·L−1). A statistically significant interaction between cell line and subculture time (24 months) was observed in the influence on proliferation rate, somatic embryo production, and percentage germination (p < 0.001). In this study, the highest somatic embryo production was achieved using cell line 37-1 (1983 somatic embryos per gram fresh mass), with approximately 83.5% of somatic embryos germinating after transferring to germination medium, of which 77.6% converted into plantlets.


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 561a-561
Author(s):  
Mary W. George ◽  
Robert R. Tripepi

Previous reports of somatic embryogenesis on rose tissues involved an embryogenic callus stage with either a complicated multi-step process or low numbers of embryos being produced. We have produced somatic embryos without a callus stage from leaf explants of the cut rose cultivar `Golden Emblem' by using a two step process. Explants were obtained from microshoots of `Golden Emblem' that had been in culture for three years. All experiments were repeated twice. When explants were maintained on Murashige and Skoog (MS) with 0.4 μM NAA and 0.4 μM kinetin for 10 weeks, 10% or less of the explants produced somatic embryos. Keeping the explants on the NAA/kinetin medium for two weeks, then switching to medium with 0, 0.5, 1.0, or 10.0 μM kinetin for the remaining 8 weeks failed to increase embryo production. Decreasing the time the explants were on the NAA/kinetin medium to 8 or 12 days, and then placing explants on MS medium with 1.0 μM kinetin increased somatic embryo production to a maximum of 25%. By limiting the length of time the rose leaf explants were exposed to auxin, direct somatic embryo production was increased.


Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 416
Author(s):  
Tuija Aronen ◽  
Susanna Virta ◽  
Saila Varis

Telomeres i.e., termini of the eukaryotic chromosomes protect chromosomes during DNA replication. Shortening of telomeres, either due to stress or ageing is related to replicative cellular senescence. There is little information on the effect of biotechnological methods, such as tissue culture via somatic embryogenesis (SE) or cryopreservation on plant telomeres, even if these techniques are widely applied. The aim of the present study was to examine telomeres of Norway spruce (Picea abies (L.) Karst.) during SE initiation, proliferation, embryo maturation, and cryopreservation to reveal potential ageing or stress-related effects that could explain variation observed at SE process. Altogether, 33 genotypes from 25 families were studied. SE initiation containing several stress factors cause telomere shortening in Norway spruce. Following initiation, the telomere length of the embryogenic tissues (ETs) and embryos produced remains unchanged up to one year of culture, with remarkable genotypic variation. Being prolonged in vitro culture can, however, shorten the telomeres and should be avoided. This is achieved by successful cryopreservation treatment preserving telomere length. Somatic embryo production capacity of the ETs was observed to vary a lot not only among the genotypes, but also from one timepoint to another. No connection between embryo production and telomere length was found, so this variation remains unexplained.


Author(s):  
Tingyu Sun ◽  
Yanli Wang ◽  
Lihua Zhu ◽  
Xiaowei Liu ◽  
Qingtong Wang ◽  
...  

AbstractTo determine the optimal embryogenic capacity (somatic embryo production) of the selected elite nematode-resistant genotypes of Pinus thunbergii, variables such as embryogenic tissue (ET) morphology, maternal genotype, proliferation rate and tissue age were analyzed. ET morphology and histological evaluation of the proliferation stage showed a decrease in filamentous clump and protuberant surfaces and a decline in the acetocarmine-staining area, which indicates a decrease in somatic embryo production (SEP). Variations in cell physiology during the proliferation stage showed that SEP was positively correlated with soluble sugars and proteins, but negatively correlated with starch, peroxidase, and superoxidase. In addition, SEP was significantly (p < 0.001) affected by maternal genotype, tissue age and proliferation rate. Moreover, SEP was positively correlated with proliferation rate (r = 0.98, p < 0.001), but negatively correlated with tissue age (r =  − 0.95, p < 0.001). In general, the results suggest that SEP could be assessed in ET proliferation stages by the apparent cell morphology, histology, proliferation rate and tissue age, which provides novel insights for evaluating the ET maturation capacity (number of somatic embryos) during the proliferation stage of P. thunbergii somatic embryogenesis.


2000 ◽  
Vol 23 (4) ◽  
pp. 865-868 ◽  
Author(s):  
Gisele Aparecida Bonacin ◽  
Antonio Orlando Di Mauro ◽  
Roberto Carlos de Oliveira ◽  
Dilermando Perecin

The embryogenic capability of five soybean cultivars (Renascença, IAS-5, IAC-17, BR-16 and FT-Cometa) was studied at different auxin concentrations (8, 10 and 12 mg/l naphthalene acetic acid, NAA), at different pHs (5.8 and 7.0) and at low (8-12 muEm-2 s-1) and high (27-33 mEm-2 s-1) light intensities. The experimental design was completely randomized with four replications. Immature cotyledons 4-6 mm in length were placed in the six induction mediums evaluated and submitted to two light intensities. Twenty immature cotyledons per cultivar were placed on each Petri dish, which was considered to be one replication. The number of somatic embryos per treatment per replication was counted. The results showed genotype influence on somatic embryogenic capability of each cultivar, with the most embryogenic cultivars being BR-16, FT-Cometa and IAS-5. Auxin concentration and pH value also influenced somatic embryo production, with 10 mg/l NAA being the best auxin concentration and 7.0 the best pH value. The interactions cultivar x auxin, auxin x pH and pH x light were significant, while other double interactions were not. All triple and quadruple interactions were significant, except cultivar x pH x light. No significant differences in somatic embryo production were observed in medium with different pHs or when the Petri dishes containing immature cotyledons were exposed to the two light intensities evaluated. However, a higher number of somatic embryos was produced when the medium pH was adjusted to 7.0.


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