Clonal variation in pollen-related characteristics of Douglas-fir

1982 ◽  
Vol 12 (2) ◽  
pp. 403-408 ◽  
Author(s):  
W. T. Adams
Keyword(s):  
Genetic Variation ◽  
Pollen Grains ◽  
Seed Orchard ◽  
Douglas Fir ◽  
Clonal Variation ◽  
Pollen Production ◽  
The Mean ◽  
Pollen Cone ◽  
Grain Diameter

The mean number of pollen grains produced per pollen cone (P) ranged from 37 310 to 62 960 ([Formula: see text], SE = 1584) among eight seed-orchard clones of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and correlated significantly (r = 0.87, p < 0.05) with the mean number of microsporophylls per cone but not significantly with pollen cone length. The number of pollen grains per milligram (G) also differed among clones (range 2323–3112; [Formula: see text], SE = 32) and correlated significantly and negatively (r = −0.86) with grain diameter. Although this study provides evidence for genetic variation in both P and G, the differences were relatively small. Adjusting pollen-cone counts for P would add little, if any, precision to estimates of pollen production in seed-orchard clones. If balanced clonal representation in pollen mixes is desired, equal weights of pollen would probably suffice for most breeding applications.

Mating system variation among individual ramets in a Douglas-fir seed orchard

1990 ◽  
Vol 20 (10) ◽  
pp. 1672-1675 ◽  
Author(s):  
V. J. Erickson ◽  
W. T. Adams
Keyword(s):  
Mating System ◽  
Seed Orchard ◽  
Floral Biology ◽  
Douglas Fir ◽  
Pollen Production ◽  
Male And Female ◽  
Floral Phenology ◽  
Female Flowering ◽  
High Degree

Proportions of outcrossed progeny (ti) in five ramets of five clones with variable floral phenology and pollen production were investigated in a Douglas-fir (Pseudotsugamenziesii var. menziesii (Mirb.) Franco) seed orchard. Estimates of ti[Formula: see text] were significantly heterogeneous among the five ramets, ranging in value from 0.50 to 1.07. Variation in [Formula: see text] corresponded well with variation among ramets in floral biology. Ramets that flowered much earlier than other individuals in the orchard and (or) had a high degree of synchrony in timing of male and female flowering produced the lowest [Formula: see text].

scholarly journals Anther and Pollen Morphology and Anatomy in Walnut (Juglans regia L.)

HortScience ◽  
2010 ◽  
Vol 45 (5) ◽  
pp. 757-760 ◽  
Author(s):  
Cevriye Mert
Keyword(s):  
Electron Microscopy ◽  
Pollen Morphology ◽  
Juglans Regia ◽  
Staminate Flower ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Pollen Production ◽  
Transmission Electron ◽  
Pollen Surface ◽  
The Mean

The morphology and ultrastructure of anthers and pollen grains were described for eight walnut (Juglans regia L.) cultivars (Şebin, Bilecik, Kaman I, Kaplan 86, Yalova 3, Pedro, Hartley, and Franquette) using light microscopy and scanning and transmission electron microscopy. Anther and pollen dimensions and pollen production capabilities were also determined. The mean number of stamens per staminate flower (14.90 to 20.03) and mean anther dimensions (1412.5 to 2553.5 μm in length and 849.0 to 1145.5 μm in width) differed significantly among the cultivars. The number of pollen grains per anther also varied significantly and ranged from 4720 to 9840 among the cultivars. The pollen grains of walnut plants are spherical in shape (nearly circular) and pantocolporate (with many colporate apertures on the exine). The pollen surface is microechinate with spiniferous projections. The germination pores are circular and nonbordered. Pollen grain length varied from 33.35 to 37.50 μm in the examined cultivars. The ultrastructure of the pollen walls was similar between walnut cultivars. The exine was comprised of nexine and sexine, which was thicker than the underlying nexine. The sexine appeared as a strong tectum that was traversed by thin channels and decorated with spinulose processes. The thicknesses of the various layers of the pollen wall were as follows: intine: 82.1 to 200 nm; exine: 793.1 to 1161.1 nm; and total wall: 954.4 to 1327.8 nm.

scholarly journals Flowering and nectar and pollen flow in Geranium sanguineum L., Geraniaceae

2012 ◽  
Vol 59 (1) ◽  
pp. 165-175 ◽  
Author(s):  
Marzena Masierowska
Keyword(s):  
Honey Bees ◽  
Pollen Grains ◽  
Pollen Production ◽  
Flowering Period ◽  
Flower Buds ◽  
Total Sugars ◽  
Flower Nectar ◽  
Modified Stomata ◽  
Floral Nectaries ◽  
The Mean

This 3-year study examined the seasonal and daily dynamics of blooming, as well as the nectar and pollen production in <i>Geranium sanguineum</i> L. Moreover, the type and localization of floral nectaries were observed using LM and SEM, and measurements of pollen grains were performed. The visitation of insects on flowers was monitored, too. <i>Geranium sanguineum</i> bloomed from the beginning of May until the middle of July with the peak occurring between the second and the fifth week of flowering period. Most of the flower buds opened on plants in the afternoon hours. Flowers are protandrous. In a flower, nectar is secreted by five phanarothetic-discoid nectaries and it flows through modified stomata. It was found that one gland is bigger than the others. Ten flowers produced 30.58 mg of highly concentrated nectar, on average. The mean mass of total sugars secreted in nectar per 10 flowers was 7.94 mg. Pollen mass per 10 flowers was 23.14 mg, on average. Tricolpate, spherical pollen grains can be classified as very big size (sporae permagne). Flowers of <i>G. sanguineum</i> were visited mainly by honey bees, bumble bees and flies. Insects collected mainly nectar.

Effects of pollen tube number and archegonium number on reproduction in Douglas-fir: significance for seed orchard management

1992 ◽  
Vol 22 (10) ◽  
pp. 1483-1488 ◽  
Author(s):  
Reed W. Crook ◽  
William E. Friedman
Keyword(s):  
Pollen Tube ◽  
Effective Means ◽  
Seed Orchard ◽  
Douglas Fir ◽  
Clonal Variation ◽  
Tube Number ◽  
Orchard Management ◽  
Number Increase ◽  
Selection Of ◽  
Significant Bearing

Analyses of the relationships between pollen tube number and fertilization number and between archegonium number and fertilization number in Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) indicate strong trends toward higher levels of simple polyembryony as both pollen tube number and archegonial number increase on a per-seed basis. These relationships have a significant bearing on the management of conifer seed orchards. Simple polyembryony has been proposed to be an effective means of increasing competition on a per-seed basis in conifers and, potentially, the overall fitness of progeny. In conifers, supplemental mass pollination has the direct effect of increasing the number of pollen tubes per ovule. Clonal variation in average number of archegonia per ovule is also likely to exist among conifers. We propose that when used together, supplemental mass pollination and selection of clones with high archegonial averages may enhance the fitness of seed orchard progeny.

Interaction between gibberellin A4/7 and root-pruning on the reproductive and vegetative process in Douglas-fir. I. Effects on flowering

1985 ◽  
Vol 15 (2) ◽  
pp. 341-347 ◽  
Author(s):  
S. D. Ross ◽  
J. E. Webber ◽  
R. P. Pharis ◽  
J. N. Owens
Keyword(s):  
Seed Orchard ◽  
Douglas Fir ◽  
Individual Treatment ◽  
Root Pruning ◽  
Male And Female ◽  
The Poor ◽  
Female Flowering ◽  
Pollen Cone ◽  
Sexually Mature ◽  
Effective Cone

In two seed orchard trials, profuse female flowering was induced in young, but ontogenetieally mature grafts of inherently poor-flowering clones (1979) and in 9-year-old seedling-origin trees of both good- and poor-flowering families (1981) of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) by the cultural treatment of root-pruning in conjunction with stem injections of the gibberellin A4 and A7 (GA4/7) mixture. Promotion of male flowering, however, was confined to the more sexually mature grafts. As an individual treatment in the 1981 study, root-pruning was more effective than GA4/7, particularly for the poor-flowering families which did not respond well to GA4/7 alone. The two treatments combined had a highly synergistic effect on both male and female flowering, the synergism being relatively greater for the poor-flowering than for the good-flowering families. Although GA4/7 was not tested alone on grafted propagules, its use with root-pruning enhanced an already significant increase in seed- and pollen-cone buds from root-pruning alone by 540 and 92%, respectively. These and subsequent trials have shown root-pruning +GA4/7 to be a most effective cone-bud enhancement treatment for use in young Douglas-fir breeding and seed production orchards.

scholarly journals Characterization of Deleterious Mutations in Outcrossing Populations

Genetics ◽  
1998 ◽  
Vol 150 (2) ◽  
pp. 945-956 ◽  
Author(s):  
Hong-Wen Deng
Keyword(s):  
Genetic Variation ◽  
Genetic Variance ◽  
Estimation Bias ◽  
Deleterious Mutations ◽  
Environmental Variance ◽  
Higher Power ◽  
Sib Mating ◽  
The Mean ◽  
Simulation Results

Abstract Deng and Lynch recently proposed estimating the rate and effects of deleterious genomic mutations from changes in the mean and genetic variance of fitness upon selfing/outcrossing in outcrossing/highly selfing populations. The utility of our original estimation approach is limited in outcrossing populations, since selfing may not always be feasible. Here we extend the approach to any form of inbreeding in outcrossing populations. By simulations, the statistical properties of the estimation under a common form of inbreeding (sib mating) are investigated under a range of biologically plausible situations. The efficiencies of different degrees of inbreeding and two different experimental designs of estimation are also investigated. We found that estimation using the total genetic variation in the inbred generation is generally more efficient than employing the genetic variation among the mean of inbred families, and that higher degree of inbreeding employed in experiments yields higher power for estimation. The simulation results of the magnitude and direction of estimation bias under variable or epistatic mutation effects may provide a basis for accurate inferences of deleterious mutations. Simulations accounting for environmental variance of fitness suggest that, under full-sib mating, our extension can achieve reasonably well an estimation with sample sizes of only ∼2000-3000.

POLLEN PRODUCTION AND DISSEMINATING PROPERTIES OF TRITICALE RELATIVE TO WHEAT

1972 ◽  
Vol 52 (4) ◽  
pp. 569-574 ◽  
Author(s):  
K. C. YEUNG ◽  
E. N. LARTER
Keyword(s):  
Seed Set ◽  
Marker Gene ◽  
Pollen Grains ◽  
Triticum Aestivum L ◽  
Hybrid Seed Production ◽  
Pollen Production ◽  
Hexaploid Triticale ◽  
Anther Length ◽  
Anther Extrusion ◽  
Wide Range

A study of the pollen production properties of three hexaploid triticale strains (Triticale hexaploide Lart.) showed that their anther length was significantly greater than that of wheat anthers (Triticum aestivum L. em Thell.) and the estimated number of pollen grains per anther ranged from 15,000 to 21,000. In comparison, a total of 8000 grains per anther was estimated for wheat, cult Manitou. Eighty-nine percent anther extrusion occurred in triticale cult Rosner, while Manitou averaged 70% anther extrusion. The period of anthesis of triticale varied according to strain but generally was of longer duration than in Manitou and thereby promoted outcrossing. Using a triticale strain carrying a dominant marker gene, 50% seed-set was obtained at a distance of 12 m leeward of the pollen source; however, a small percentage was still obtained at a distance of 30 m. It would appear from the limited number of triticales used in this study that a wide range of variability exists within this species in its pollen production and disseminating properties. With appropriate selection pressures, strains with an outbreeding habit could be developed for the purpose of hybrid seed production.

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