scholarly journals Abscisic acid induces somatic embryogenesis and enables the capture of high-value genotypes in Douglas fir (Pseudotsuga menziesii [MIRB.] Franco)

2021 ◽  
Author(s):  
Madlen Walther ◽  
Isabel Wagner ◽  
Juliane Raschke ◽  
Kurt Zoglauer ◽  
Andrea Rupps
Keyword(s):  
Somatic Embryogenesis ◽  
Abscisic Acid ◽  
Plant Growth ◽  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Zygotic Embryos ◽  
Morphological Development ◽  
Hormonal Stimulation ◽  
Breeding Programs ◽  
Genotype Effect

AbstractDouglas fir (Pseudotsuga menziesii) is one of Europe’s most important non-native tree species due to its drought tolerance as well as timber quality and yield. To obtain superior seed from selected parental trees, breeding programs had been established in seed orchards. Douglas fir seed is used as source material for somatic embryogenesis with the aim to select elite genotypes invaluable for clonal mass propagation. To improve given protocols for somatic embryo initiation, we used immature Douglas fir zygotic embryos as explants and abscisic acid (ABA) as plant growth regulator in contrast to the application of auxins and cytokinins. With ABA supplementation, induction frequencies were slightly but in mean higher than with auxin/cytokinin, showing also a strong genotype effect. This offered the possibility to capture SE cultures from otherwise recalcitrant crosses. Furthermore, we observed remarkable differences between the two sets of plant growth regulators concerning the morphological development of the explants, including the absence of non-embryogenic callus by using ABA as inducer. This simplifies the detection of events and the handling of the obtained cultures. Nevertheless, a histological approach suggested, that the same competent cells are addressed by the different hormonal stimulation. Besides, we studied the influence of different points in time of cone harvest, two different basal media and different genetic backgrounds of the explants as well as the maturation ability of the induced embryogenic cultures. In sum, we were able to improve the first steps of somatic embryogenesis and to maintain a significantly higher number of high-value genotypes.

Initiation and morphological development of somatic embryoids from barley cell cultures

1984 ◽  
Vol 62 (6) ◽  
pp. 1245-1249 ◽  
Author(s):  
L. S. Kott ◽  
K. J. Kasha
Keyword(s):  
Somatic Embryogenesis ◽  
Abscisic Acid ◽  
Gibberellic Acid ◽  
Cell Cultures ◽  
Dichlorophenoxyacetic Acid ◽  
Morphological Development ◽  
Low Concentrations ◽  
The Media ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Barley Cell

Somatic embryogenesis was induced in callus previously initiated from immature embryos of barley. These cultures ranged in age from 6 weeks to 30 months. Embryoids were readily initiated from homogenized suspension-grown aggregates when plated on modified B5 media with 2,4-dichlorophenoxyacetic acid. Low concentrations (0.1 and 0.05 mg∙L−1) of abscisic acid promoted further maturation of embryoids, while gibberellic acid (1 mg∙L−1) and kinetin (0.1 mg∙L−1) were used in the media to encourage embryoid germination. The development of somatic embryoids from initiation through maturation and germination is described.

Somatic Embryogenesis in Douglas-fir (Pseudotsuga Menziesii)

1995 ◽  
pp. 303-313 ◽  
Author(s):  
Pramod K. Gupta ◽  
Roger Timmis ◽  
Kathleen A. Timmis ◽  
William C. Carlson ◽  
Elaine D. E. Welty
Keyword(s):  
Somatic Embryogenesis ◽  
Pseudotsuga Menziesii ◽  
Douglas Fir

Abscisic acid levels and stomatal behavior during drought and recovery in Douglas-fir (Pseudotsuga menziesii)

1980 ◽  
Vol 58 (12) ◽  
pp. 1370-1375 ◽  
Author(s):  
Edward G. Newville ◽  
William K. Ferrell
Keyword(s):  
Abscisic Acid ◽  
Water Potential ◽  
Pseudotsuga Menziesii ◽  
Stomatal Closure ◽  
Moisture Stress ◽  
Douglas Fir ◽  
Potential Range ◽  
Stomatal Behavior ◽  
Leaf Resistance ◽  
Growth Room

Foliage of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings from xeric and mesic environments was sampled during two induced, consecutive, drought cycles to determine relationships among leaf resistance, plant water potential, and abscisic acid (ABA) concentration. One group of seedlings was placed in a growth room; the other was kept outside at a nursery under natural conditions. During the first drought cycle, seedlings transpired similarly. During the second drought, xeric seedlings in the growth room and nursery initiated stomatal closure at greater levels of plant moisture stress (PMS) than in the first drought cycle, but stomatal behavior of mesic seedlings was unchanged. During the first drought cycle, a sharp increase in ABA concentration in both ecotypes coincided with increased leaf resistance within a narrow water-potential range. However, after xeric seedlings were rewatered and then subjected to drought, leaf resistances remained low even though the previous threshold PMS and ABA concentrations for stomatal closure were reached. For mesic seedlings in the growth room, ABA concentrations remained high after rewatering and slowly decreased with time, although recovery to predrought leaf resistances was largely completed 2 days after rewatering.

Somatic Embryogenesis and Plant Development in Eight Cultivars of Pecan

HortScience ◽  
1990 ◽  
Vol 25 (5) ◽  
pp. 573-576 ◽  
Author(s):  
I.E. Yates ◽  
C.C. Reilly
Keyword(s):  
Somatic Embryogenesis ◽  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Plant Development ◽  
Fruit Development ◽  
Somatic Embryos ◽  
Carya Illinoensis ◽  
Appreciable Variation

The influence of stage of fruit development and plant growth regulators on somatic embryogenesis and the relation of cultivar response on somatic embryogenesis and subsequent plant development have been investigated in eight cultivars of pecan [Carya illinoensis (Wangenh.) C. Koch]. Explants from the micropylar region of the ovule were more embryogenic when removed from fruits in the liquid endosperm stage than were intact ovules from less-mature fruits or from cotyledonary segments of more-mature fruits. Explants conditioned on medium containing auxin alone or auxin + cytokinin produced more somatic embryos than medium containing cytokinin alone. Under the conditions of this study, frequency of embryogenesis, as well as the germination of somatic embryos leading to plant development, indicated appreciable variation among cultivars. Plant development was greatest by far from somatic embryos of `Schley' than other cultivars studied.

scholarly journals Pathogenicity and Virulence of Pythium Species Obtained from Forest Nursery Soils on Douglas-Fir Seedlings

Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 744-748 ◽  
Author(s):  
Jerry E. Weiland ◽  
Bryan R. Beck ◽  
Anne Davis
Keyword(s):  
Pseudotsuga Menziesii ◽  
Seedling Survival ◽  
The United States ◽  
Douglas Fir ◽  
Tree Seedlings ◽  
Pythium Species ◽  
Forest Nursery ◽  
Damping Off ◽  
Greenhouse Study ◽  
Forest Nurseries

Pythium species are common soilborne oomycetes that occur in forest nursery soils throughout the United States. Numerous species have been described from nursery soils. However, with the exception of P. aphanidermatum, P. irregulare, P. sylvaticum, and P. ultimum, little is known about the potential for other Pythium species found in nursery soils to cause damping-off of tree seedlings. A greenhouse study was conducted to evaluate the pathogenicity and virulence of 44 Pythium isolates representing 16 species that were originally recovered from soil at three forest nurseries in Washington and Oregon. Seeds of Douglas-fir (Pseudotsuga menziesii) were planted into soil infested with each of the isolates. Seedling survival, the number of surviving seedlings with necrotic root lesions, and taproot length were evaluated 4 weeks later. Responses of Douglas-fir to inoculation varied significantly depending on Pythium species and isolate. Eight species (P. dissotocum, P. irregulare, P. aff. macrosporum, P. mamillatum, P. aff. oopapillum, P. rostratifingens, P. sylvaticum, and P. ultimum var. ultimum) significantly reduced the number of surviving seedlings compared to the noninoculated treatment. However, all Pythium species caused a greater percentage of seedlings to develop root lesions (total mean 40%) than was observed from noninoculated seedlings (17%). Taproot length varied little among Pythium treatments and was not a useful character for evaluating pathogenicity. Results confirm the ability of P. irregulare, P. mamillatum, and P. ultimum var. ultimum to cause damping-off of Douglas-fir seedlings, and are indicative that other species such as P. dissotocum, P. aff. macrosporum, P. aff. oopapillum, P. rostratifingens, and P. sylvaticum may also be responsible for seedling loss.

Cylindrocarpon and Fusarium root colonization of Douglas-fir seedlings from British Columbia reforestation sites

1998 ◽  
Vol 28 (8) ◽  
pp. 1198-1206 ◽  
Author(s):  
Paige E Axelrood ◽  
William K Chapman ◽  
Keith A Seifert ◽  
David B Trotter ◽  
Gwen Shrimpton
Keyword(s):  
British Columbia ◽  
Pseudotsuga Menziesii ◽  
Root Colonization ◽  
Linear Trend ◽  
Poor Performance ◽  
Douglas Fir ◽  
Root Infection ◽  
Significant Linear Trend ◽  
Conifer Seedlings ◽  
Cylindrocarpon Destructans

Poor performance of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) plantations established in 1987 has occurred in southwestern British Columbia. Affected sites were planted with 1-year-old container stock that exhibited some root dieback in the nursery. A study was initiated in 1991 to assess Cylindrocarpon and Fusarium root infection in planted and naturally regenerating (natural) Douglas-fir seedlings from seven affected plantations. Percentages of seedlings harboring Cylindrocarpon spp.and percent root colonization were significantly greater for planted seedlings compared with natural seedlings. A significant linear trend in Cylindrocarpon root colonization was observed for planted seedlings with colonization levels being highest for roots closest to the remnants of the root plug and decreasing at distances greater than 10cm from that region. This trend in Cylindrocarpon colonization was not observed for natural seedlings. Cylindrocarpon destructans (Zins.) Scholten var. destructans and C.cylindroides Wollenw. var. cylindroides were the only species isolated from planted and natural conifer seedlings. For most sites, percentage of seedlings harboring Fusarium spp.and percent Fusarium root colonization were less than for Cylindrocarpon. Recovery of Fusarium spp.from seedlings and root colonization levels were not significantly different for planted and natural seedlings from all sites.

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