Clonal-row versus random seed orchard designs: interior spruce mating system evaluation

2007 ◽  
Vol 37 (3) ◽  
pp. 690-696 ◽  
Author(s):  
Y.A. El-Kassaby ◽  
M.U. Stoehr ◽  
D. Reid ◽  
C.G. Walsh ◽  
T.E. Lee
Keyword(s):  
Mating System ◽  
Minor Component ◽  
Slight Modification ◽  
Seed Orchard ◽  
Outcrossing Rate ◽  
Genetic Quality ◽  
Seed Orchards ◽  
Interior Spruce ◽  
Seed Crops ◽  
A Minor

Mating system pattern (selfing or outcrossing and correlated matings levels) comparisons between two interior spruce seed orchard designs (clonal-row and random) managed under intensive crown and pollen management were conducted. Crown manipulation consisted of tree topping and branch pruning, while pollen management involved multiple supplemental mass-pollination applications during peak seed-cone reproductive receptivity and pollen agitation using helicopters. Significant differences between orchards’ multilocus outcrossing rate estimates were observed, and both estimates significantly departed from complete outcrossing (t = 1.0). Clonal arrangements in the clonal-row design permitted higher chances for selfing (t = 0.948) in comparison with those of the random design (t = 0.989). Intensive pollen management, while effective, still produced a minor component of selfing. Both orchard designs produced similar individual tree's outcrossing rate trends with the majority showing high outcrossing, while few individuals showed high selfing propensity. Estimates of correlated mating varied substantially between the two seed orchard designs with 9.3% and 4.3% for the clonal-row and random seed orchards, respectively. While small but significant differences in the genetic quality of the seed crops were observed between the two orchard designs, the establishment of clonal-row seed orchards should be given serious considerations specifically under committed pollen and crown management. The ease of crop and orchard management in the clonal-row design outweighs the observed differences in the seed crop genetic quality. A slight modification to the clonal-row design is proposed and is expected to reduce the observed minor genetic quality differences between the two orchard designs.

Field performance and early test results of offspring from two Norway spruce seed orchards containing clones transferred to warmer climates

2007 ◽  
Vol 37 (3) ◽  
pp. 515-522 ◽  
Author(s):  
Tore Skrøppa ◽  
Ketil Kohmann ◽  
Øystein Johnsen ◽  
Arne Steffenrem ◽  
Øyvind M. Edvardsen
Keyword(s):  
Norway Spruce ◽  
Field Performance ◽  
Seed Orchard ◽  
Field Trials ◽  
Climatic Conditions ◽  
Test Results ◽  
Seed Orchards ◽  
Low Altitude ◽  
Natural Stands ◽  
Seed Crops

We present results from early tests and field trials of offspring from two Norway spruce ( Picea abies (L.) Karst.) seed orchards containing clones that have been transferred from high altitudes to sea level and from northern to southern latitudes. Seedlings from seeds produced in the low-altitude seed orchard developed frost hardiness later at the end of the growth season, flushed later in field trials, and grew taller than seedlings from seeds produced in natural stands. They had the lowest mortality rate and the lowest frequency of injuries in the field trials. Similar results were observed in seedlings from seeds produced in the southern seed orchard. We found no adverse effects of the changed growth rhythm. Seedlings from two seed crops in the southern orchard, produced in years with a warm and a cold summer, had different annual growth rhythms. The results are explained mainly by the effects of the climatic conditions during the reproductive phase. Seed crops from different years in the same seed orchard may produce seedlings that perform as if they were from different provenances. It is argued that the effects of the climatic conditions during seed production must contribute to the variation among provenances of Norway spruce.

scholarly journals Crossing Success in Abies nordmanniana Following Artificial Pollination With a Pollen Mixture of A. nordmanniana and A. alba

2008 ◽  
Vol 57 (1-6) ◽  
pp. 70-76 ◽  
Author(s):  
O. K. Hansen ◽  
U. B. Nielsen
Keyword(s):  
Abies Alba ◽  
Seed Orchard ◽  
Reproductive Barriers ◽  
Seed Orchards ◽  
Abies Nordmanniana ◽  
Pollen Mixture ◽  
Set Up ◽  
Mating Interaction ◽  
Seed Crops ◽  
Siring Success

AbstractControlled crossings were conducted with three Abies nordmanniana genotypes acting as mothers and a pollen mixture of three Abies nordmanniana genotypes and one Abies alba genotype acting as potential fathers. The aim was to investigate hybridization success under circumstances where pollen from both species are present, which is a potential risk in Danish clonal seed orchards of Abies nordmanniana. The number of seeds sired by each father was determined through SSRs and compared to the expected numbers based on the pollen mixture composition. All three mother genotypes of Abies nordmanniana had more progenies with the Abies alba as father (hybrids) than expected, based on proportions in the pollen mix. This indicates that no reproductive barriers between the two species exist, and that seed orchard managers should take precautions to avoid hybrids in seed crops. Furthermore, the experiments revealed quite different siring success of the three Abies nordmanniana genotypes, depending on which clone was the mother. Abies nordmanniana seed orchards should therefore not be established in the vicinity of Abies alba in the flowering age, and if a few-clone set up is chosen, the mating interaction should be investigated beforehand through pollen mix experiments.

scholarly journals Variation in Platycladus orientalis (Cupressaceae) Reproductive Output and Its Effect on Seed Orchard Crops’ Genetic Diversity

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1429
Author(s):  
Siqian Jiao ◽  
Meiyu Li ◽  
Yuanjiao Zhu ◽  
Shanshan Zhou ◽  
Shiwei Zhao ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Reproductive Output ◽  
First Generation ◽  
Seed Orchard ◽  
Effective Number ◽  
Ecological Value ◽  
Seed Orchards ◽  
Platycladus Orientalis ◽  
Fertility Variation ◽  
Seed Crops

The genetic efficiency of seed orchards is crucial for determining seed crops’ genetic gain and diversity. Platycladus orientalis is a conifer tree of important ecological value in China. Here, we assessed the reproductive output (fertility) variation for 166 clones in a first-generation P. orientalis seed orchard over five years and across three years for each gender (female: 2017, 2018, and 2020 and male: 2017, 2019, and 2021). Fertility variation and genetic diversity parameters were estimated for each gender-year combination. The reproductive output (fertility) variation differed among years, provinces, clones nested within provinces, and ramets within clones. We observed asymmetry in the gender reproductive output and parental imbalance and determined their profound effects on the genetic diversity of these seed crops. The maleness index revealed the existence of female-biased or male-biased clones. When seeds from multiple individuals and years were blended, we found an increase in the effective number of parents (Np) and in genetic diversity (GD), and a reduced fertility variation (Ψ) in the seed orchard. When we set the effective number of parents (Np) to 30, the GD of the seed orchard could be maintained at more than 95%. Thus, achieving genetic diversity balance in seed production can be accomplished through monitoring the fertility variation of orchards and through the utilization of the thereby generated information for the advanced generation of seed orchards.

Determination of paternal and maternal parentage in lodgepole pine seed: full versus partial pedigree reconstruction

2014 ◽  
Vol 44 (9) ◽  
pp. 1122-1127 ◽  
Author(s):  
Tomas Funda ◽  
Cherdsak Liewlaksaneeyanawin ◽  
Yousry A. El-Kassaby
Keyword(s):  
Reproductive Success ◽  
Lodgepole Pine ◽  
Seed Orchard ◽  
Simultaneous Estimation ◽  
Male Reproductive Success ◽  
Pedigree Reconstruction ◽  
Chloroplast Microsatellite ◽  
Seed Orchards ◽  
Reconstruction Methods ◽  
Seed Crops

Estimating seed orchards’ maternal and paternal gametic contributions is of importance in assessing the genetic quality of seed crops. The advantage of full over partial pedigree reconstruction in investigating the mating dynamics in a lodgepole pine (Pinus contorta Dougl. ex. Loud. ssp. latifolia Engelm.) seed orchard population (N = 74) was demonstrated using nuclear and chloroplast microsatellite markers. We analyzed offspring of equivalent sample sizes representing full (bulk seed with unknown maternal and paternal parentage (n = 635)) and partial (11 maternal family arrays (n = 619)) pedigree reconstruction methods. Small differences in selfing rate, gene flow, and male reproductive success were observed between the two methods; however, the full pedigree reconstruction enabled simultaneous estimation of female-related fertility parameters (female reproductive success and effective number of maternal parents) that partial pedigree reconstruction could not provide. The use of bulk random sample of seed from orchards’ crops is recommended when male and female fertility parameters, as well as selfing and contamination rates, are needed for seed orchards’ seed crops genetic rating.

TEMPORAL VARIATION OF THE MATING SYSTEM IN A NATURAL POPULATION OF JACK PINE

Genetics ◽  
1985 ◽  
Vol 109 (3) ◽  
pp. 569-584
Author(s):  
W M Cheliak ◽  
B P Dancik ◽  
K Morgan ◽  
F C H Yeh ◽  
C Strobeck
Keyword(s):  
Mating System ◽  
Pinus Banksiana ◽  
Minor Component ◽  
Linear Increase ◽  
Complex Nature ◽  
Mixed Mating ◽  
Mixed Mating System ◽  
Family Structures ◽  
Filial Generation ◽  
A Minor

ABSTRACT Mating system parameters of a northern conifer, Pinus banksiana Lamb., were estimated from allozyme polymorphisms. Seeds analyzed were obtained from serotinous cones of 30 individuals and represented four independent fertilizations in 1975, 1976, 1977 and 1978. Results indicated that a mixed mating system model, with a mean effective outcrossing rate of 88 ± 0.047%, described the mating system of this stand. However, there was an approximately linear increase in the apparent selfing rate from the oldest (1975) to the newest (1978) crop. Two hypotheses could account for these observations. First, there may have been changes in the mating system during the 4-yr period, but linearity of the differences observed in this study may have been due to chance. These changes were, however, independent of the variability of the observed pollen pool. This indicated that they were not a result of different proportions of outcrossed zygotes directly observed. Second, there could have been a more or less constant amount of selfing, followed by a differential loss of viability of selfed and outcrossed zygotes during the period of storage in the cones. Under this hypothesis, selfed zygotes are at a selective disadvantage relative to outcrossed zygotes. No differences in the mating system could be demonstrated among the three crown strata of this stand. There was significant interlocus heterogeneity in the filial generation genotypic distributions and in the estimated outcrossing rates, reflecting the complex nature of forces that can affect single-locus estimates. There was evidence of some additional inbreeding, possibly due to family structures in the stand; however, this was a minor component of the total inbreeding.

scholarly journals Microsatellite Based Paternity Analysis in a Clonal Eucalyptus nitens Seed Orchard

2010 ◽  
Vol 59 (1-6) ◽  
pp. 57-62 ◽  
Author(s):  
C. Grosser ◽  
B. M. Potts ◽  
René E. Vaillancourt
Keyword(s):  
Microsatellite Markers ◽  
Seed Orchard ◽  
Paternity Analysis ◽  
Outcrossing Rate ◽  
Eucalyptus Nitens ◽  
Seed Orchards ◽  
Seed Crop ◽  
Paternal Contribution ◽  
Low Levels

Abstract Microsatellite markers were used to determine paternity in 473 open-pollinated progenies from a clonal Eucalyptus nitens seed orchard of 50 trees from 12 different genotypes. The outcrossing rate in this orchard was high, averaging 0.85 (weighted by capsule crop) but variable between trees (ranging from 0.6-1.0). Paternal contribution of each genotype to the open-pollinated seed crop was predicted by the size of the flower crop of each genotype (r = 0.76), but not the number of ramets. While the detectable contamination in this orchard is relatively low (4.5%), it is atypical when compared to other published estimates in eucalypt seed orchards suggesting that with suitable buffering low levels of contamination can be achieved.

The mating system in natural populations of western redcedar (Thuja plicata)

2001 ◽  
Vol 79 (6) ◽  
pp. 753-756 ◽  
Author(s):  
Lisa M O'Connell ◽  
Frédérique Viard ◽  
John Russell ◽  
Kermit Ritland
Keyword(s):  
British Columbia ◽  
Mating System ◽  
Natural Populations ◽  
Seed Orchard ◽  
Outcrossing Rate ◽  
Thuja Plicata ◽  
Western Redcedar ◽  
Outcrossing Rates ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Thuja Plicata Donn

Outcrossing rates and the correlation of paternity were estimated in six natural populations of western redcedar (Thuja plicata Donn. ex D. Don) in southwestern British Columbia. Over 3000 offspring were assayed, as progeny arrays, for the only sufficiently polymorphic isozyme locus in this species, glucose-6-phosphate dehydrogenase. Estimates of population outcrossing rates ranged from 0.173 to 1.257 and averaged 0.715 ± 0.045 (mean ± SD). Estimates of the correlation of paternity generally did not differ from zero. Six of the seven outcrossing estimates (one population was surveyed in two consecutive years) were higher than a previous seed orchard study. However, these outcrossing rates are still lower than those estimated for most other species of conifers. Population outcrossing rates also showed wide variation, and this variation is discussed in terms of ecological and phenological differences among populations.Key words: Cupressaceae, conifers, isozymes, outcrossing rate, inbreeding.

Protonation effects on dynamic flux properties of aqueous metal complexes

2009 ◽  
Vol 74 (10) ◽  
pp. 1543-1557 ◽  
Author(s):  
Herman P. Van Leeuwen ◽  
Raewyn M. Town
Keyword(s):  
Complex Formation ◽  
Metal Ion ◽  
Good Description ◽  
Minor Component ◽  
Outer Sphere ◽  
Metal Species ◽  
Central Metal ◽  
Inner Sphere ◽  
A Minor ◽  
Protonated Ligand

The degree of (de)protonation of aqueous metal species has significant consequences for the kinetics of complex formation/dissociation. All protonated forms of both the ligand and the hydrated central metal ion contribute to the rate of complex formation to an extent weighted by the pertaining outer-sphere stabilities. Likewise, the lifetime of the uncomplexed metal is determined by all the various protonated ligand species. Therefore, the interfacial reaction layer thickness, μ, and the ensuing kinetic flux, Jkin, are more involved than in the conventional case. All inner-sphere complexes contribute to the overall rate of dissociation, as weighted by their respective rate constants for dissociation, kd. The presence of inner-sphere deprotonated H2O, or of outer-sphere protonated ligand, generally has a great impact on kd of the inner-sphere complex. Consequently, the overall flux can be dominated by a species that is a minor component of the bulk speciation. The concepts are shown to provide a good description of experimental stripping chronopotentiometric data for several protonated metal–ligand systems.

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