scholarly journals Variation in Male Fertilities and Pairwise Mating Probabilities in Picea glauca

Genetics ◽  
1987 ◽  
Vol 116 (1) ◽  
pp. 141-152
Author(s):  
D J Schoen ◽  
S C Stewart

ABSTRACT Frequencies of multilocus male gametes in seeds collected from clones in several blocks of a white spruce seed orchard were analyzed as part of a 2-yr study of mating system variation in this species. Observed frequencies of male gamete types departed significantly from those expected assuming equal male fertilities among clones. Male gamete frequencies in seed crops were significantly heterogeneous among clones within blocks, and among blocks within clones. Clonal male fertilities were estimated from male gamete frequency data. These estimates were highly skewed, with a small proportion of the clones contributing male gametes to the majority of the seed. The estimates were significantly heterogeneous among clones within blocks, and among blocks within clones. Between-year variation in clonal male fertilities was also pronounced, with male fertilities of some clones changing by as much as three orders of magnitude. Clonal male fertility was significantly correlated with clonal male cone production in both years. These results are important with regard to assumptions made for the estimation of general combining ability, average genetic correlation among progeny from single parents, and expected response to selection in open-pollinated plant populations.

1982 ◽  
Vol 58 (1) ◽  
pp. 31-34 ◽  
Author(s):  
J. A. McPherson ◽  
E. K. Morgenstern ◽  
B. S. P. Wang

One seed orchard each of black spruce (Picea mariana) [Mill.] B.S.P.) and white spruce (Picea glauca) [Moench] Voss) was established in northern Ontario gradually during the 1958-78 period. Each species was represented by approximately 45 clones and 450 ramets. During the whole period, records were kept of cone production by individual ramets and of seed production by clones expressed as average number of seeds per cone extracted and germinated. Substantial cone production began 8 years after grafting in black spruce and after 10 years in white spruce. The figures indicated that a clonal orchard of black spruce planted at 5 × 5 m spacing (400 ramets) produces approximately 1 million sound seeds per ha per year; the white spruce equivalent is 900 000. Conditions of cone development and cone storage and damage by insects and fungi can reduce germination of the sound seed harvested by about 20%.


1980 ◽  
Vol 10 (3) ◽  
pp. 405-414 ◽  
Author(s):  
E. E. McMullan

Extracts of buds and young shoots of a good cone-producing clone of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were tested for cone production effect on seed orchard Douglas-fir trees chosen for their history of poor cone production. Other metabolites, including gibberellin 4/7, arginine, and abscisic acid were also tested. Growth regulator levels in good and poor cone-producing clones of Douglas-fir were compared over the period of bud break and shoot elongation.No evidence was obtained for the presence of growth regulators critical to cone production in purified extracts from ramets of the good cone-producing clone. Applied gibberellin 4/7 increased male and female cone production. Crude extracts of a good cone-producing clone increased male cone bud production. Arginine and abscisic acid had no effect.Bioassays indicated that growth regulator levels in buds and young shoots changed greatly with stage of development but were similar in good and poor cone-producing clones.


Nature ◽  
1965 ◽  
Vol 206 (4985) ◽  
pp. 739-739 ◽  
Author(s):  
G. B. SWEET ◽  
G. M. WILL

2006 ◽  
Vol 36 (4) ◽  
pp. 1054-1058 ◽  
Author(s):  
O K Hansen ◽  
E D Kjær

A paternity analysis using five microsatellite markers was conducted in a Danish clonal seed orchard with 13 Abies nordmanniana (Stev.) Spach clones. The purpose was to investigate potential seed-orchard dysfunctions, with special emphasis on nonequal pollen contributions and selfing. Male paternity was found for 232 seedlings germinated from seeds collected on three ramets, each of eight clones, and the relative contribution of each clone to the gene pool of male gametes was calculated. Furthermore, 49 ramets were genotyped to check for erroneous grafting. The effect of an unbalanced male contribution was quantified by means of two measures: (1) the status number (NS), which reflects buildup of coancestry in the seed-orchard crop as a result of a low number of clones and an unequal male contribution, and (2) the asymptotic variance effective population number (Ne(v)). The contributions by pollen donors from the 13 clones were highly skewed. Three clones were fathers to more than 75% of the progenies, while making up only 24% of the ramets in the seed orchard. Four clones sired no progenies at all. The unequal contribution on the male side corresponded to NS = 4.2 and Ne(v) = 5.8. Some selfing was observed, which may give rise to concern if clonal seed orchards with few clones are established. The estimated maximum pollen contamination from outside the seed orchard was 4.3%. No grafting–labelling errors were identified.


2007 ◽  
Vol 37 (3) ◽  
pp. 515-522 ◽  
Author(s):  
Tore Skrøppa ◽  
Ketil Kohmann ◽  
Øystein Johnsen ◽  
Arne Steffenrem ◽  
Øyvind M. Edvardsen

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.


1988 ◽  
Vol 18 (1) ◽  
pp. 139-142 ◽  
Author(s):  
Rong H. Ho

Black spruce (Piceamariana (Mill.) B.S.P.) grafts growing in a seed orchard were sprayed with gibberellin A4/7, and grafts and trees in families growing in arboreta were sprayed with gibberellin A4/7 and (or) vitamin E from vegetative bud burst to the end of shoot elongation. Gibberellin A4/7 was very effective in promoting seed cones and 400 mg/L appeared optimal. Vitamin E at 1000 mg/L was not effective. Vegetative bud burst occurred in mid-May and shoot elongation ended in late June. Needle primordia were visible on the apices of newly formed buds at the end of June. Reproductive buds had fewer bud scales than vegetative buds. It appeared that potential reproductive buds terminated their bud scale initiation earlier. Gibberellin A4/7 application to promote seed-cone production should be carried out before bud-type differentiation. This coincides with the end of lateral shoot elongation.


2000 ◽  
Vol 30 (7) ◽  
pp. 1096-1105 ◽  
Author(s):  
C DB Hawkins ◽  
K B Shewan

Fifteen seed lots, five each from natural-stand, seed-orchard, and full-sib collections, of interior spruce (Picea glauca (Moench) Voss, Picea engelmannii Parry ex Engelm., and their naturally occurring hybrids) were sown in February 1993. One half of each seed lot received an ambient photoperiod (control) treatment, while the other half got a blackout (short-day) treatment. All seedlings were grown under ambient photoperiod except during the 17 days of blackout. Frost hardiness assessments were done between July and May. Blackout treatment was effective in regulating height and promoting frost hardiness in all seed lots, particularly vigorous ones. Seed lots originating from high latitude or elevation were more frost hardy both at fall lift and spring planting. Full-sib seed lots from similar latitude displayed no elevational frost-hardiness trend. Blackout treatment promoted seedling dormancy (estimated with days to bud break) at lift, but it had little or no effect on dormancy at planting. Seedling dormancy and frost hardiness were acquired and lost differently, suggesting that they are independent physiological processes. Blackout treatment significantly reduced new roots at planting in all lots. This could retard early field performance and negate the apparent utility of blackout treatment.


2004 ◽  
Vol 53 (1-6) ◽  
pp. 7-11 ◽  
Author(s):  
Z. Zhuowen

Abstract Data from three seed orchards (Chongyang, Zhangle and Laoshan) and Lintian forest were used to study pollination characteristics, pollination level, pollen and ovule production in Chinese fir. The results show that male and female cones have their own distribution patterns within crowns. Male cones are located in the middle to top and female cones the middle to bottom part of the crown. Because of lower density of trees in seed orchard than that in a stand, female cones are distributed over the entire crown in seed orchard trees. Chinese fir male and female cones appear to be very well adapted for wind as the pollination mechanism. There is no difference in the number of pollen grains produced by one pollen sac among trees in the same clone, but there are differences between clones. There are differences between both clones and years in female cone number, male cone number and their ratio. The pollen accumulation rate during pollination should be 3 to 5 pollen grains/mm2 to ensure fertilization. The Chinese fir seed orchards in this study produced too much pollen and could be improved by stimulation of more female flowers in order to produce more seeds.


Author(s):  
C. Marc Luetjens ◽  
Gerhard F. Weinbauer

The testes fulfil two essential functions: the production and maturation of the male gametes and synthesis and the secretion of the sexual hormones. Unless otherwise specified, this chapter describes the situation in the human and provides the basis for understanding the endocrine and local regulation of testicular function. Data obtained in experimental animals are presented when the corresponding human mechanisms are not known or cannot be clarified for ethical reasons.


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