Erratum: Synchronous and high frequency germination of interior spruce somatic embryos following partial drying at high relative humidity

The germination of mature somatic embryos of interior spruce was limited by the low frequency of root emergence. In addition, development was abnormal, since elongation and greening of the hypocotyl and cotyledons preceded root emergence by 1–2 weeks. Pretreatment of the embryos on water-saturated Kim-paks increased the frequency of root emergence but did not alter the abnormal pattern of germination. Somatic embryos do not survive desiccation at room humidity, but partial drying at high humidity promoted germination up to 90%. Furthermore, this treatment decreased the time required for root emergence such that elongation of the root and hypocotyl–cotyledon was synchronized over a period of 5–6 days. This germination closely resembled that of excised zygotic embryos. Drying over a range of humidities indicated that humidities of 81% and lower were lethal to the embryos, whereas germination was enhanced following treatment at humidities greater than 95% relative to untreated controls. The best germination and root elongation occurred on one-half strength basal media containing 2–3.4% sucrose. Of the plantlets derived from treated embryos, 50% survived transfer to soil compared with only 5% of the untreated controls. Key words: conifers, desiccation, germination, high relative humidity, partial drying, somatic embryogenesis, spruce.

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Propagation of interior spruce by somatic embryogenesis

Canadian Journal of Forest Research ◽

10.1139/x90-234 ◽

1990 ◽

Vol 20 (11) ◽

pp. 1759-1765 ◽

Cited By ~ 57

Author(s):

F. B. Webster ◽

D. R. Roberts ◽

S. M. McInnis ◽

B. C. S. Sutton

Keyword(s):

Somatic Embryogenesis ◽

Abscisic Acid ◽

Relative Humidity ◽

Somatic Embryos ◽

Large Scale ◽

Final Height ◽

High Relative Humidity ◽

Mature Embryos ◽

Interior Spruce ◽

General Production

To apply somatic embryogenesis to clonal propagation of forest species, the technique must be applicable to a broad range of genotypes and allow efficient regeneration of phenotypically normal plants. Seventy-one lines (genotypes) of embryogenic cultures from six open-pollinated families were obtained by culturing immature embryos of interior spruce. Interior spruce represents a mixture of two closely related species, Piceaglauca (Moench) Voss and Piceaengelmannii Parry, from the interior of British Columbia where they hydridize with one another. The abscisic acid dependent developmental profile (the proportion of rooty embryos, shooty embryos, precociously germinating embryos, and mature embryos over a range of abscisic acid concentrations) differed among genotypes, but in general, production of mature somatic embryos was highest at 40 and 60 μM abscisic acid. Treatment of mature embryos with a high relative humidity treatment resulted in partial drying of the embryos and upon rehydration, markedly enhanced germination of the eight genotypes tested. Within 1 week of being placed under germination conditions, somatic embryos treated with the high relative humidity treatment showed 80–100% germination for 12 of the genotypes, and most genotypes had germination rates of greater than 40%. Survival of "emblings" (germinants from somatic embryos) following transfer to soil, acclimatization, and first season's growth in the nursery was 80% or greater for most genotypes. Over 1200 emblings were tested for nursery performance, representing the first large-scale evaluation of conifer somatic embryos under exvitro conditions. Growth rates, final height, shoot and root morphology, and frost hardiness were similar for emblings and seedlings following the first growing season. These results indicate that somatic embryogenesis can be used for the production of planting stock for a range of interior spruce genotypes.

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Interaction between Maturation and High Relative Humidity Treatments and their Effects on Germination of Sitka Spruce Somatic Embryos

Journal of Plant Physiology ◽

10.1016/s0176-1617(11)80720-0 ◽

1991 ◽

Vol 138 (1) ◽

pp. 1-6 ◽

Cited By ~ 40

Author(s):

D.R. Roberts ◽

W.R. Lazaroff ◽

F.B. Webster

Keyword(s):

Relative Humidity ◽

Somatic Embryos ◽

Sitka Spruce ◽

High Relative Humidity

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Improved eddy covariance flux based transpiration estimates at high relative humidity and comparison to sap flux

10.5194/egusphere-egu21-14177 ◽

2021 ◽

Author(s):

Weijie Zhang ◽

Jacob A. Nelson ◽

Rafael Poyatos ◽

Diego Miralles ◽

Mirco Migliavacca ◽

...

Keyword(s):

Water Vapor ◽

Relative Humidity ◽

Eddy Covariance ◽

High Frequency ◽

High Relative Humidity ◽

Closed Path ◽

Sap Flux ◽

Water Vapor Flux ◽

Vapor Flux ◽

Flux Measurements

Eddy covariance (EC) directly measures evapotranspiration (ET), which consists of transpiration and evaporation (E) from the soil and other surfaces. For process understanding it is pivotal to separate ET into its components. Yet, its computation is highly sensitive to the methodology used to estimate T. Among the multiple methods proposed in recent years, T has been estimated from EC via the Transpiration Estimation Algorithm (TEA, Nelson et al., 2020), and from the sap flux measurement network SAPFLUXNET (Poyatos et al., 2020). These methods are applicable to a large number of measurement sites worldwide, and can help constrain the global estimates of the ratio of T to ET, T/ET. While EC measures water and carbon fluxes across ecosystems globally, water vapor flux measurements can be underestimated at high relative humidity (Ibrom et al., 2007; Mammarella et al., 2009) causing errors in the measured ET and propagating into the predicted T.Here we report a method to detect and correct the high relative humidity error caused by attenuation of high frequency in water vapor measurements of a closed-path EC system. Our results of the comparison between present water use efficiency (WUE) with previous TEA-based WUE show that the corrected WUE is lower at high relative humidity than that derived from previous TEA at the sub-daily scale. Besides, we compare the corrected T estimates from EC to concurrent SAPFLUXNET sites to show an improved relationship between sap flux and EC based T, T/ET, and WUE. Finally, we explore the main abiotic factors, such as vapor pressure deficit, air temperature, and precipitation, influencing WUE estimated from different T estimation methodologies. These results provide an improved data-driven approach to the ongoing research on ET partitioning and the factors influencing the WUE across ecosystems globally.&#160;Ibrom, A. et al. (2007) &#8216;Strong low-pass filtering effects on water vapour flux measurements with closed-path eddy correlation systems&#8217;, Agricultural and Forest Meteorology. doi.org/10.1016/j.agrformet.2007.07.007.Mammarella, I. et al. (2009) &#8216;Relative humidity effect on the high-frequency attenuation of water vapor flux measured by a closed-path eddy covariance system&#8217;, Journal of Atmospheric and Oceanic Technology. doi.org/10.1175/2009JTECHA1179.1.Nelson, J. A. et al. (2020) &#8216;Ecosystem transpiration and evaporation: Insights from three water flux partitioning methods across FLUXNET sites&#8217;, Global Change Biology. doi: 10.1111/gcb.15314.Poyatos, R. et al. (2020) &#8216;Global transpiration data from sap flow measurements: the SAPFLUXNET database&#8217;, Earth System Science Data. doi:10.5194/essd-2020-227.

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