Effect of different inbreeding levels on filled seed production in Douglas-fir

1989 ◽  
Vol 19 (1) ◽  
pp. 54-59 ◽  
Author(s):  
J. H. Woods ◽  
J. C. Heaman

Matings of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were performed to develop inbreeding levels with inbreeding coefficient (F) values from 0.0 to 0.75. A strong inverse linear relationship was found between filled seed per cone and F at values ≤0.5. The following mean filled seed per cone values were obtained: outcross (F = 0.0), 31.6; half-sib cross (F = 0.125), 21.3; full-sib cross (F = 0.25), 16.7; parent–offspring backcross (F = 0.25), 15.5; self (F = 0.5), 1.2; second generation self (F = 0.75), 0.03. Parental effects on filled seed per cone were large, accounting for about 50% of the total variation. The use of related clones in a seed orchard will result in less inbred seed than expected under total panmixia, owing to decreased filled seed production at all inbred levels. Also, breeding programs will require increased effort to obtain seed when mating designs include crosses between related trees.

1997 ◽  
Vol 129 (1) ◽  
pp. 7-19 ◽  
Author(s):  
Marc Jarry ◽  
Jean-Noël Candau ◽  
Alain Roques ◽  
Bernard Ycart

AbstractThe invasion of a Douglas-fir seed orchard by host-specific seed chalcids immigrating from the surrounding plantations of Douglas-fir has been monitored for a 10-year period. The orchard cone crop was entirely harvested every year to prevent the establishment of a resident chalcid population. Over the 10 years the percentage of infested seeds resulting from the immigration of seed chalcids ranged from 0.88 to 91.0%. A model to forecast the importance of annual seed orchard infestation by immigrating populations is proposed. This model is based on passive diffusion of females emerging in the surrounding plantations with a downwind drift. Only a few plantations located within a radius of 5 km from the orchard appeared to contribute significantly to orchard infestation. Settlement of Douglas-fir orchard in regions with low density of conspecific trees and annual harvest of cones are suggested to limit the importance and regularity of seed chalcid damage.


1976 ◽  
Vol 52 (6) ◽  
pp. 283-289 ◽  
Author(s):  
C. W. Yeatman

A program of provenance testing, seed production and genetic improvement of jack pine was developed in the Baskatong region of western Quebec through sustained collaboration among government forest services and forest industry. Research plantations demonstrated, within a period of 10 years from establishment, the superiority in growth, cold hardiness and disease resistance of regionally adapted local seed sources. Critical differences were evident between provenances from the Boreal Forest Region and those from the adjacent Sections of the Great Lakes — St. Lawrence Forest Region.A 300-acre (120 ha) seed production area was created within a genetically superior jack pine population of natural origin in the Côte Jaune area west of Lake Baskatong. Within this population, 325 plus trees were selected, marked and recorded over two years by student crews employed in the summer. Seed harvested from the felled plus trees will be used to create a seedling seed orchard and to establish progeny tests. The plus trees are to be grafted for controlled breeding among selected progeny-tested clones at a later date. This cooperative program of tree improvement will ensure the future supply of high quality seed that will maintain and enhance the value of the forest resource.


1989 ◽  
Vol 19 (10) ◽  
pp. 1322-1329 ◽  
Author(s):  
G. H. Mohammed ◽  
K. R. Patel ◽  
W. E. Vidaver

Rooting percentage and root number in tissue-cultured Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were influenced by the rooting substrate, the concentration of sucrose and boron in the rooting medium, shoot height, and shoot generation. Peat–perlite was a better substrate than agar, producing 70% compared with 0% rooted shoots, respectively. On peat–perlite, cell divisions were organized and were associated with tracheid nests, whereas on agar proliferation was unorganized and not restricted to the nests. A sucrose concentration of 4% was optimal for the production of nodular or rooted shoots. At 4% sucrose and 3 mg •L−1 boric acid, 100% of the shoots rooted, and the mean root number was 11. Rooting percentage and root number were significantly higher with shoots that were 3 cm tall than 2 or 1 cm tall shoots. Finally, it was found that shoot responses were more rapid in third and fourth generation shoots than in second generation shoots. At least 80% were rooted or nodular after 4 weeks, compared with only 36% from the second generation.


1982 ◽  
Vol 6 (3) ◽  
pp. 177-180
Author(s):  
J. B. Jett ◽  
J. T. Talbert

Abstract Data from thinnings of 11 genetic tests with an average age of 10 years and from 364 eight-year-old second-generation selections were analyzed to provide an estimate of gain from one cycle of selection for wood specific gravity. Utilizing mid-parent, mature, wood specific gravities and progeny juvenile wood specific gravities, coefficients of genetic prediction, CGP = 0.55 and 0.41, were calculated for the genetic test thinning sample and second-generation selection sample. Expressed as a percentage of the mean, gain from selection was calculated to be 2.6 percent. A strategy was also developed to include wood specific gravity in the North Carolina State Cooperative's second-generation loblolly pine (Pinus taeda L.) improvement program. High heritability figures indicate little need to develop extensive family information for wood specific gravity in advanced-generation breeding programs.


1981 ◽  
Vol 11 (3) ◽  
pp. 512-516 ◽  
Author(s):  
Michael N. Todhunter ◽  
R. Brooks Polk

Seed and cone production in Pinusbanksiana Lamb. was studied using clonal material. Variables studied included sound seed per cone, sound seed percentage, seed efficiency, total seed per cone, seed potential, and total number of cones in relation to site, clone, and position in the crown. The clonal effect was highly significant for all variables. Site and crown location were significant for all but seed total and number of cones. Due to the variability present, cone and seed production should be taken into account in seed orchard design, tree selection, and breeding.


1987 ◽  
Vol 17 (6) ◽  
pp. 510-515 ◽  
Author(s):  
Thomas A. Thomson ◽  
Donald T. Lester ◽  
Jeanne A. Martin

We use marginal analysis for three seed orchard management decisions. First we consider the roguing of a seed orchard established with many untested trees. We show that inferior parents should be rogued to the point where the number of orchard trees times the average expected volume gain of trees from seed produced by that orchard is maximized. Marginal analysis also is useful where one must choose the number of trees to establish in an orchard planted after progeny tests have identified superior parents. The cost of establishing many ramets to meet early seed production goals can be balanced with the projected value of seed. For the example presented, an additional orchard tree is cost effective if its seed is needed at an orchard age of 12 to 15 years. Finally, we use marginal analysis to determine whether to induce a seed orchard to increase its seed production when there is an excess demand for seed. This decision is guided by balancing the cost of the induction treatment with the combined effect of expected increase in seed harvest, the amount of genetic gain, and the discount rate. We present a four-quadrant decision diagram for estimating this balance. In designing tree improvement programs, these analytical techniques can be applied to proposed alternatives as one way to structure decision making and to provide comparable economic assessments from which cost-effective choices can be made.


2005 ◽  
Vol 35 (7) ◽  
pp. 1592-1603 ◽  
Author(s):  
Gancho T Slavov ◽  
Glenn T Howe ◽  
W Thomas Adams

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.


2012 ◽  
Vol 4 (10) ◽  
Author(s):  
Miroslawa Staniaszek ◽  
Katarzyna Szajko ◽  
Elzbieta U. Kozik ◽  
Marzena Nowakowska ◽  
Waldemar Marczewski

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