Pollen contamination trends in a maturing Douglas-fir seed orchard

1997 ◽  
Vol 27 (1) ◽  
pp. 131-134 ◽  
Author(s):  
W T Adams ◽  
V D Hipkins ◽  
J Burczyk ◽  
W K Randall
Keyword(s):  
Seed Orchard ◽  
Douglas Fir ◽  
Pollen Contamination

Pollen contamination and mating patterns in a Douglas-fir seed orchard as measured by simple sequence repeat markers

2005 ◽  
Vol 35 (7) ◽  
pp. 1592-1603 ◽  
Author(s):  
Gancho T Slavov ◽  
Glenn T Howe ◽  
W Thomas Adams
Keyword(s):  
Ssr Markers ◽  
Simple Sequence Repeat ◽  
Female Parent ◽  
Seed Orchard ◽  
Douglas Fir ◽  
Sequence Repeat ◽  
Female Receptivity ◽  
Mating Patterns ◽  
Pollen Contamination ◽  
Simple Sequence

Pollen contamination is detrimental to the genetic quality of seed orchard crops. Highly variable simple sequence repeat (SSR) markers make it possible to accurately measure pollen contamination and characterize patterns of within-orchard mating by directly identifying the male and female parent of each seed produced in the orchard. We used nine SSR markers to measure pollen contamination and characterize mating patterns based on seed samples collected in 3 years (1999, 2000, and 2003) from one block of a nonisolated, open-pollinated, clonal seed orchard of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in western Oregon. Pollen contamination was consistently high across the 3 years (mean = 35.3%, range = 31.0%-41.3%) and appeared to result primarily from cross-pollination among the orchard blocks. Levels of pollen contamination varied substantially among clones and were higher in clones with early female receptivity (mean = 55.5%) than in those with either mid (mean = 36.4%) or late (mean = 28.3%) female receptivity. We detected low rates of self-pollination (mean = 1.8% per clone) and over 10-fold differences in the relative paternal contributions of the clones. There was a clear pattern of positive assortative mating with respect to floral phenology. This study illustrates that SSR markers are powerful tools for characterizing seed lots and improving the design and management of Douglas-fir seed orchards.

Mating system and pollen contamination in a Douglas-fir clone bank

1986 ◽  
Vol 16 (6) ◽  
pp. 1314-1319 ◽  
Author(s):  
Willi Fast ◽  
Bruce P. Dancik ◽  
Ralph C. Bower
Keyword(s):  
Mating System ◽  
Seed Orchard ◽  
Douglas Fir ◽  
Pollen Contamination ◽  
Outcrossing Rates ◽  
Natural Stands

Pollen contamination and mating system of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) clone banks used as an interim seed orchard near Nanaimo, B.C., were estimated. Pollen contamination (m) from surrounding clone banks and natural stands ranged from 0.44 to 0.89. Overall contamination over 2 years was estimated to be 0.65. Pollen contamination varied significantly over 2 pollination years. Multilocus outcrossing rates (t) of four clone banks over 2 years ranged from 0.51 to 1.09, with an unweighted mean outcrossing estimate of 0.72. Outcrossing varied significantly among clone banks and pollination years. An excess of homozygotes suggests that these seed may be inbred. Although pollen contamination and inbreeding may be a problem in these clone banks, the seed may still be useful operationally.

scholarly journals A Practical Solution to Douglas-Fir Seed Orchard Pollen Contamination

1980 ◽  
Vol 56 (5) ◽  
pp. 237-241 ◽  
Author(s):  
A. M. K. Fashler ◽  
W. J. B. Devitt
Keyword(s):  
Irrigation System ◽  
Seed Orchard ◽  
Douglas Fir ◽  
Flight Period ◽  
Water Cooling ◽  
Flower Bud ◽  
Pollen Contamination ◽  
Threshold Temperatures ◽  
Bud Opening ◽  
Selection Of

Based on work by Silen and Keane (1969), research was carried out in the early 1970's to evaluate the effectiveness of delaying reproductive bud development in a Douglas-fir seed orchard by cooling the trees with water spray. The results from these first trials indicated a 10 to 14 day delay in reproductive bud opening giving up to 85% control of local pollen contamination. A solid set irrigation system was then installed for flower bud cooling and was applied to the 1976 and 1978 seed orchard cone crops. In both years phenological and pollen flight data showed results similar to the trials; the operational cooling treatment kept the female reproductive buds unopened through the major portion of the local pollen flight period in approximately 76% of the Douglas-fir clones in the orchard. No adverse side effects have been observed. Calculation of the heat sum and threshold temperatures for Douglas-fir reproductive buds will provide a means to measure the amount of cooling achieved through irrigation and a method to calibrate the irrigation system for most efficient use. The expense of water-cooling as a solution to pollen contamination is justified by the value of the improved seed derived from seed orchard production. The investment is also off-set by the selection of a multi-purpose system that can be applied for irrigation, fertilization and frost protection as well as cooling. Another advantage of the water-cooling is a decrease in the amount of insect infestation in the orchard trees.

Pollen contamination effects on progeny from an off-site Douglas-fir seed orchard

1994 ◽  
Vol 24 (10) ◽  
pp. 2113-2117 ◽  
Author(s):  
Michael U. Stoehr ◽  
Joe E. Webber ◽  
Roger A. Painter
Keyword(s):  
Growth Rate ◽  
Transition Zone ◽  
Final Height ◽  
Seed Orchard ◽  
Height Growth ◽  
Douglas Fir ◽  
Logistic Growth ◽  
Maximum Height ◽  
Growth Cessation ◽  
Pollen Contamination

The effects of background pollen contamination were evaluated for first-year height growth pattern of seedlings originating from a Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) coastal–interior transition zone seed orchard located on southern Vancouver Island, British Columbia. Pollen collected from five stands surrounding the orchard (background pollen) and pollen from five half-sib families of the seed orchard were applied to six individual trees in the orchard. The resulting 60 seed lots were raised outdoors in a coastal-climate nursery with five seed lots collected from wild stands of the transition zone. Heights were measured in 10-day intervals during the growing season. Final heights, maximum height growth rate, and growth cessation were subjected to analysis of variance. Growth rate and cessation were derived from data fitted to the logistic growth curve using nonlinear regression analysis. Seedlings sired by the background pollen had significantly greater final heights and growth rates. There were no differences in orchard seedlings in growth cessation probably because all seedlings were exposed to a blackout treatment to force bud set in mid-August. The average final height of wild-stand seedlings from the transition zone was 15% and 21% lower than that of pure orchard seedlings and seedlings sired by the background pollen lots, respectively. Standard deviations for measured traits were similar between orchard seedlings sired by background pollen and orchard pollen. If pollen contamination is not prevented, the faster growing seedlings sired by the background pollen may be preferentially selected during culling in the nursery and outplanted on sites to which they are maladapted.

Estimates of pollen contamination and selfing in a coastal Douglas-fir seed orchard

2015 ◽  
pp. 1-10 ◽  
Author(s):  
Tony Kess ◽  
Yousry A. El-Kassaby
Keyword(s):  
Seed Orchard ◽  
Douglas Fir ◽  
Pollen Contamination

Potential pollen contamination effects on progeny from an off-site Douglas-fir seed orchard: 9-year field results

2004 ◽  
Vol 34 (4) ◽  
pp. 981-984 ◽  
Author(s):  
M U Stoehr ◽  
J E Webber ◽  
C CA Hollefreund ◽  
R A Painter
Keyword(s):  
Transition Zone ◽  
Seed Orchard ◽  
Douglas Fir ◽  
Coastal Site ◽  
Management Implications ◽  
Pollen Contamination ◽  
Growing Seasons ◽  
Orchard Management ◽  
Pollen Sources ◽  
Contamination Effects

To evaluate the potential effects of seed orchard pollen contamination from surrounding background sources, we made control pollinations with outside orchard pollen and inside orchard pollen on trees of a Douglas-fir (Pseudo tsuga menziesii (Mirb.) Franco) coastal–interior transition zone seed orchard. The resulting progeny were tested on a transition zone and a coastal site. After nine growing seasons, survival was above 90% on both sites for both pollen sources, and the trees height differences due to pollen source were statistically nonsignificant. Wildstand operational seedlots, used as controls, were 17% shorter than the "contaminated" seedlings. Orchard management implications of these results are discussed.

Annual Variation in Pollen Contamination and Outcrossing in a Picea abies Seed Orchard

2000 ◽  
Vol 15 (4) ◽  
pp. 399-404 ◽  
Author(s):  
Anne Pakkanen ◽  
Teijo Nikkanen ◽  
Pertti Pulkkinen
Keyword(s):  
Picea Abies ◽  
Annual Variation ◽  
Seed Orchard ◽  
Pollen Contamination

scholarly journals Survival and Growth of Douglas-Fir Relating to Weeding, Fertilization, and Seed Source

1996 ◽  
Vol 11 (2) ◽  
pp. 62-69 ◽  
Author(s):  
Brian E. Roth ◽  
Michael Newton
Keyword(s):  
Weed Control ◽  
Nitrogen Fertilization ◽  
Seedling Survival ◽  
Seed Orchard ◽  
Douglas Fir ◽  
Seed Source ◽  
Interactive Effects ◽  
Dominant Factor ◽  
Local Source ◽  
Survival And Growth

Abstract The goal of this study was to quantitatively evaluate the individual and interactive effects of weed control, nitrogen fertilization, and seed source on Douglas-fir (Pseudotsuga menziesii) survival and growth in a range of sites and growing conditions in western Oregon. Weed control was the dominant factor influencing seedling survival and growth and accounted for 49% of the explained variation in seedling volume after 2 yr. Nitrogen fertilization had no effect when used in conjunction with weed control and a negative effect when used without weed control. Seedlings from a seed orchard source were significantly larger in diameter and volume than those from a wild local source after two growing seasons, but second-year heights were similar for the two seedling types. Initial seedling size was positively correlated with growth rate. West. J. Appl. For. 11(2):00-00.

Factors affecting pollen dynamics and its importance to pollen contamination: a review

1991 ◽  
Vol 21 (8) ◽  
pp. 1155-1170 ◽  
Author(s):  
F. Di-Giovanni ◽  
P. G. Kevan
Keyword(s):  
Gene Flow ◽  
Pollen Dispersal ◽  
Past Research ◽  
Seed Orchard ◽  
Dispersal Pattern ◽  
Seed Orchards ◽  
Factors Affecting ◽  
Pollen Contamination ◽  
Modelling Techniques ◽  
Natural Stands

Pollen contamination causes major losses to genetic improvement from selection and breeding of "plus" trees in conifer seed orchards. Genetic losses arise by the influx of "wild" conspecific pollen into seed orchards and its deleterious fertilization of superior genetic lines. This review firstly addresses the basis of the problem: pollen, conifer reproduction, and the concept of seed orchard management, especially in regard to reduction of contamination. Secondly, the physical processes of pollen liberation, dispersal, and deposition are described, and examples of previous studies illuminating these phenomena given. Thirdly, past research on measuring pollen dispersal in natural stands and seed orchards in discussed in the light of modelling techniques used to predict these types of dispersal pattern. Work on the other facets of contamination measurement, gene-flow studies, are listed. It is concluded that a detailed study that combines both the physical and gene-flow aspects of pollen dispersal should be initiated to compare and contrast the two methods, and that attempts to model pollen contamination should be sought.

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