Comparisons of gas exchange parameters and shoot water relations of interior spruce (Picea glauca (Moench) Voss times Picea engelmannii Parry ex Engelm.) clones under repeated soil drought

1998 ◽  
Vol 28 (6) ◽  
pp. 820-830 ◽  
Author(s):  
Shihe Fan ◽  
Steven C Grossnickle
Keyword(s):  
Water Relations ◽  
Picea Glauca ◽  
Net Photosynthesis ◽  
Picea Engelmannii ◽  
Soil Drought ◽  
Gas Exchange Parameters ◽  
Tissue Water ◽  
Shoot Tissue ◽  
Interior Spruce ◽  
Exchange Parameters

Physiological response of interior spruce (Picea glauca (Moench) Voss x Picea engelmannii Parry ex Engelm.) to drought conditions was compared for somatic seedlings from clones G351, T703, N366, and W460. Seedlings were subjected to four cycles of progressive soil drought by withholding water. Changes in net photosynthesis (Pn), stomatal conductance (gwv), and predawn water potentials ( psi pd) were measured during and after each drought cycle. Shoot tissue water relations parameters were measured using pressure-volume analysis at the beginning and end of the fourth drought cycle. When comparing drought cycle 1 with drought cycle 4, clones G351, N366, and T703 showed significantly reduced Pn, but gwv of all clones was not affected. Net photosynthesis and gwv decreased with psi pd more rapidly in clone W460 than in the remaining clones. When rewatered after drought, clone T703 had the most rapid Pn and gwv recovery whereas clone G351 had the slowest recovery of Pn and gwv. Over four drought cycles, all clones photosynthesized at progressively lower psi pd, but adjustments in tissue water relations parameters were marginal. These results implied that gas exchange parameters were more sensitive than shoot tissue water relations parameters in detecting clonal variation in the physiological response of interior spruce under simulated drought conditions.

Genetic variation in summer gas exchange patterns of interior spruce (Picea glauca (Moench) Voss times Picea engelmannii Parry ex Engelm.)

1998 ◽  
Vol 28 (6) ◽  
pp. 831-840 ◽  
Author(s):  
Steven C Grossnickle ◽  
Shihe Fan
Keyword(s):  
Gas Exchange ◽  
Picea Glauca ◽  
Isotope Composition ◽  
Vapour Pressure Deficit ◽  
Net Photosynthesis ◽  
Picea Engelmannii ◽  
Gas Exchange Parameters ◽  
Exchange Processes ◽  
Intrinsic Water Use Efficiency ◽  
Interior Spruce

Interior spruce (Picea glauca (Moench) Voss x Picea engelmannii Parry ex Engelm.) somatic seedlings from a range of clones were measured for gas exchange processes in relation to summer atmospheric parameters. Carbon isotope composition ( delta 13C) of needles was compared with gas exchange parameters and intrinsic water use efficiency (WUEi). Needle conductance (gwv) decreased as vapour pressure deficit (VPD) increased. Clone T703 had the lowest gwv level across all VPD conditions, with clones G351, N366, and W460 having significantly greater gwv than clone T703 at VPD levels <2.0 kPa. Response of net photosynthesis (Pn) to photosynthetically active radiation (PAR) for all clones showed Pn to increase to PAR levels of around 1000 µmol ·m-2 ·s-1 and then, Pn rates were stable at higher PAR levels. Clones N366 and W460 had significantly greater Pn than clone T703 at all PAR levels. All clones showed Pn to decline as VPD increased, with clone W460 having the highest predicted Pn level across all VPD conditions and significantly greater Pn than clone T703. Higher WUEi was related to an increase in delta 13C, with clone T703 having the highest WUEi and delta 13C, followed by clone W460. Changes in delta 13C, for all clones, indicated a stronger relationship with gwv than with Pn.

Area-based breeding zones to minimize maladaptation

2004 ◽  
Vol 34 (3) ◽  
pp. 695-704 ◽  
Author(s):  
Gregory A O'Neill ◽  
Sally N Aitken
Keyword(s):  
Cluster Analysis ◽  
Picea Glauca ◽  
Grid Cell ◽  
Picea Engelmannii ◽  
Breeding Programs ◽  
Adaptive Value ◽  
Interior Spruce ◽  
Breeding Zone ◽  
Abc Analysis ◽  
Predetermined Number

A new breeding zone delineation scheme identifies for a given number of zones the zone-boundary placement that minimizes regional maladaptation in breeding programs. First, an adaptive map is created by using conventional genetic test data. Then, the large array of predicted adaptive values is subjected to cluster analysis, which assigns each grid cell of the region to one of a predetermined number of clusters (breeding zones) such that the sum of the squared distances between each cell's adaptive value and its cluster mean is minimized. This approach minimizes the average adaptive distance between the origin of a breeding program's selected trees and planting locations throughout the region of focus. The procedure is illustrated by the use of adaptive values of 69 interior spruce (Picea engelmannii Parry ex Engelm. × Picea glauca (Moench) Voss) open-pollinated families (sources) from southeast British Columbia, Canada. Adaptive values of each 1.5 km × 1.5 km grid cell in the 80 000-km2 region were predicted using a geneco logical model (R2 = 0.64), and the values were subjected to cluster analysis to identify breeding zone boundaries that were then mapped using a geographic information system. Regardless of the number of zones created, a regional maladaptation index was consistently smaller when zones were devised with area-based cluster (ABC) analysis than when zones were created by dividing the region into bands of equal elevational or adaptive-value widths. Application of the ABC procedure should assist in identifying the optimum breeding-zone alignment for a given number of zones.

Effects of substrate acidity and UV-B radiation on photosynthesis of radishes

2011 ◽  
Vol 6 (4) ◽  
pp. 624-631
Author(s):  
Irena Januskaitiene
Keyword(s):  
Gas Exchange ◽  
Water Use ◽  
Raphanus Sativus ◽  
Net Photosynthesis ◽  
Enzymatic Reactions ◽  
Growth Substrate ◽  
Gas Exchange Parameters ◽  
Raphanus Sativus L ◽  
Use Efficiency ◽  
Exchange Parameters

AbstractThe aim of this study was to assess the combined effect of substrate acidity (pH 4.8; pH 3.8) and 1 kJm−2d−1 UV-B radiation on photosynthesis and growth of radishes (Raphanus sativus L.). Radishes were sown in a neutral pH 6.5 peat substrate. When the second true leaf unfolded, the growth substrate was acidified using different concentration of H2SO4 and exposed to UV-B radiation for a period of ten days. Gas exchange parameters were measured with the LI-6400 portable photosynthesis system. Content of chlorophyll was evaluated spectrophotometrically. The results showed that the greatest inhibition of net photosynthesis was observed when radishes were grown in an acidified pH 3.8 substrate. The decrease of the photosynthesis of radish plants treated with both investigated factors (substrate acidity and UV-B) were lower compared to the effect of substrate acidity alone. UV-B radiation stimulated both enzymatic reactions of photosynthesis and water use efficiency of radish plants grown in acidified peat substrates. Also, investigated factors had higher impact on biomass of tuber than biomass of foliage.

Conservation and divergence of gene expression plasticity followingc. 140 million years of evolution in lodgepole pine (Pinus contorta) and interior spruce (Picea glauca × Picea engelmannii)

2014 ◽  
Vol 203 (2) ◽  
pp. 578-591 ◽  
Author(s):  
Sam Yeaman ◽  
Kathryn A. Hodgins ◽  
Haktan Suren ◽  
Kristin A. Nurkowski ◽  
Loren H. Rieseberg ◽  
...  
Keyword(s):  
Gene Expression ◽  
Picea Glauca ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Picea Engelmannii ◽  
Interior Spruce

Water stress preconditioning of black spruce seedlings from lowland and upland sites

1994 ◽  
Vol 72 (10) ◽  
pp. 1511-1518 ◽  
Author(s):  
Abdenbi Zine El Abidine ◽  
Pierre Y. Bernier ◽  
James D. Stewart ◽  
André P. Plamondon
Keyword(s):  
Water Relations ◽  
Black Spruce ◽  
Sugar Content ◽  
Net Photosynthesis ◽  
Soil Drought ◽  
Drought Period ◽  
Gas Exchanges ◽  
Total Sugar Content ◽  
Net Photosynthesis Rate ◽  
One Year

One-year-old seedlings from two pairs of upland – lowland populations were subjected to three cycles of drought preconditioning. During a subsequent fourth cycle, preconditioned seedlings and seedlings that had been maintained under well-watered conditions were subjected to a final soil drought. During the drought periods, small but significant differences in gas exchanges and water relations were observed between upland and lowland seedlings but the differences were not consistent either within each lowland – upland pair or over the four cycles. During the final drought period, preconditioned seedlings maintained significantly higher net photosynthesis rate, stomatal conductance, and transpiration rate than unconditioned seedlings. In contrast, no significant differences were found in midday water potential, total sugar content, or water relations parameters between preconditioned and unconditioned seedlings. The results suggest an absence of ecotypic variation with respect to drought tolerance in black spruce. They also suggest that preconditioning in black spruce seedlings occurs mostly through the acclimation of stomatal and photosynthetic mechanisms to drought, without active osmotic adjustment. Key words: Picea mariana, ecotype, gas exchanges, water relations, osmoregulation, preconditioning.

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