Reproductive success of orchard and nonorchard pollens during different stages of pollen shedding in a Scots pine seed orchard

1996 ◽  
Vol 26 (6) ◽  
pp. 1096-1102 ◽  
Author(s):  
Anni M. Harju ◽  
Teijo Nikkanen
Keyword(s):  
Reproductive Success ◽  
Scots Pine ◽  
Seed Orchard ◽  
Wind Pollination ◽  
Isozyme Markers ◽  
Seed Crop ◽  
Pollen Contamination ◽  
Pollination Season ◽  
Number Of Seeds

The reproductive success of orchard and nonorchard pollens was studied in seeds from megastrobili exposed during different stages of pollen shedding in a Pinussylvestris L. seed orchard. Wind pollination was controlled experimentally by isolating and then temporarily exposing the megastrobili to four different stages of pollen shedding by orchard trees. The amount of pollen contamination in the seed crop was determined using isozyme markers and an undetected gamete model. The estimated level of pollen contamination was 48% when megastrobili were exposed during the entire pollination season. Contamination was highest (60%) when megastrobili were exposed before actual pollen shedding by orchard trees, and lowest (27%) in seeds from megastrobili exposed during maximum pollen shedding by orchard trees. Reproductive success was measured several ways: as the total number of seeds produced in each treatment, as the ratio or proportion of mature cones per megastrobilus, and as the number of seeds produced per cone or megastrobilus. In 1991, reproductive success was highest before maximum pollen shedding by seed orchard trees. Pollen shedding by orchard trees occurred a few days after most megastrobili became receptive.

Low rates of pollen contamination in a Scots pine seed orchard in Sweden: the exception or the norm?

2015 ◽  
Vol 30 (7) ◽  
pp. 573-586 ◽  
Author(s):  
Tomas Funda ◽  
Ulfstand Wennström ◽  
Curt Almqvist ◽  
Takeshi Torimaru ◽  
Bengt Andersson Gull ◽  
...  
Keyword(s):  
Scots Pine ◽  
Seed Orchard ◽  
Pollen Contamination

The importance of being the first pollen in the strobili of Scots pine

2008 ◽  
Vol 38 (12) ◽  
pp. 2976-2980 ◽  
Author(s):  
Saila Varis ◽  
Arja Santanen ◽  
Anne Pakkanen ◽  
Pertti Pulkkinen
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Pollen Grains ◽  
Seed Orchard ◽  
Pollen Grain ◽  
Seed Orchards ◽  
Pollination Experiments ◽  
Seed Crop ◽  
Pollen Types ◽  
Pine Pollen

Timing of pollen arrival may affect the level of seeds fertilized by pollen from outside seed orchards, especially in seed orchards of Scots pine ( Pinus sylvestris L.) established in southern Finland with stock from northern populations. We performed sequential pollination experiments with Scots pine pollen collected from seed orchard clones originating from southern and northern Finland and recipient strobili in clones originating from southern Finland. When southern pollen was introduced first, seeds were sired equally by northern and southern genotypes. When northern pollen was introduced first, northern genotypes were found in 75% of the resulting seeds. When both pollen types were introduced at the same time, the resulting seed crop was split almost equally between northern and southern genotypes. These results do not unconditionally support the idea that the first pollen grain in the pollen chamber always fertilizes the ovum; instead, they suggest a more complex way of competition between pollen grains.

Variation of paternal contribution in a seed orchard of Cryptomeria japonica determined using microsatellite markers

2004 ◽  
Vol 34 (8) ◽  
pp. 1683-1690 ◽  
Author(s):  
Yoshinari Moriguchi ◽  
Hideaki Taira ◽  
Naoki Tani ◽  
Yoshihiko Tsumura
Keyword(s):  
Microsatellite Markers ◽  
Cryptomeria Japonica ◽  
Pollen Dispersal ◽  
Seed Orchard ◽  
Null Alleles ◽  
Contamination Rate ◽  
Seed Crop ◽  
Pollen Contamination ◽  
Self Fertilization

We investigated gene flow and pollen contamination in a seed orchard of Cryptomeria japonica D. Don using six microsatellite markers. The quality of a seed crop is determined by many factors, including the rate of pollen contamination from outside sources, degree of self-fertilization, and equality of the clones as pollen donors. The surveyed seed orchard consisted of 62 clones and a total of 360 ramets. The seeds from 12 mother trees in the seed orchard were investigated using six highly polymorphic loci with high multipaternity exclusion probability (0.999). The estimated average pollen contamination rate was high at 47.78% (±4.12%), and the clonal self-fertilization rate was 2.22% (±0.94%) when we assumed that null alleles were present. The high pollen contamination rate could dramatically reduce the quality of the seed crop. The contamination rate differed from tree to tree, but the differences were not related to the location of each individual. The levels of contribution as pollen donors differed significantly amongst clones in the seed orchard. Differences in flowering phenology and relative pollen fecundity may be responsible for the differences in paternal contributions. The effective distance of pollen dispersal in this C. japonica seed orchard seemed to be greater than previously estimated.

scholarly journals Evaluation of Pollen Contamination in an Advanced Scots Pine Seed Orchard

2009 ◽  
Vol 58 (1-6) ◽  
pp. 262-269 ◽  
Author(s):  
T. Torimaru ◽  
Xiao-Ru Wang ◽  
A. Fries ◽  
B. Andersson ◽  
D. Lindgren
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Genetic Gain ◽  
Seed Orchard ◽  
Multilocus Genotypes ◽  
Pollen Contamination ◽  
Pollen Sources ◽  
Ssr Loci ◽  
The Impact ◽  
Paternity Exclusion

Abstract The pollination pattern in a Scots pine (Pinus sylvestris L.) seed orchard consisting of 28 clones was studied using nine microsatellite (SSR) loci. The nine SSR loci produced unique multilocus genotypes for each of the orchard’s 28 clones and allowed paternal assignment of the studied 305 seed using paternity exclusion probability of 99.9%. Fifty two percent of the studied seeds were sired by outside the orchard pollen sources (i.e., pollen contamination) and as expected, low selfing (2.3%) was detected. These results are valuable for the evaluation of the seed orchard function and the impact of contamination on the expected genetic gain.

Reduction of pollen contamination in Scots pine seed orchard crop by tent isolation

2013 ◽  
Vol 28 (8) ◽  
pp. 715-723 ◽  
Author(s):  
Takeshi Torimaru ◽  
Ulfstand Wennström ◽  
Bengt Andersson ◽  
Curt Almqvist ◽  
Xiao-Ru Wang
Keyword(s):  
Scots Pine ◽  
Seed Orchard ◽  
Pollen Contamination

scholarly journals Reproductive Success of Pollen Derived From Selected and Non-Selected Sources and its Impact on the Performance of Crops in a Nematode-Resistant Japanese Black Pine Seed Orchard

2005 ◽  
Vol 54 (1-6) ◽  
pp. 69-76 ◽  
Author(s):  
Susumu Goto ◽  
A. Watanabe ◽  
F. Miyahara ◽  
Y. Mori
Keyword(s):  
Reproductive Success ◽  
Seed Orchard ◽  
Flowering Phenology ◽  
Bursaphelenchus Xylophilus ◽  
Male Reproductive Success ◽  
Pinewood Nematode ◽  
Black Pine ◽  
Pollen Contamination ◽  
Japanese Black Pine ◽  
External Sources

Abstract The reproductive success of pollen derived from selected and non-selected sources and its impact on the performance of orchard crops were evaluated, using five pairs of microsatellite markers, in a Japanese black pine (Pinus thunbergii Parl.) clonal seed orchard consisting of 16 nematode-resistant clones. The paternity of each open-pollinated seed was determined by comparing the genotypes of seeds from six clones (24 trees) with genotypes of the 16 orchard clones and two trees (N1, N2) representing other genotypes that had been inadvertently included in the orchard. Out of 384 seeds examined, the paternity of 316 seeds (82.3%) was assigned to the clones within the seed orchard. On average, the male reproductive success of orchard clones varied from 0.0% to 10.5%, and was significantly related to the male-flowering fecundity of each clone. It was not related to the synchrony of flowering phenology between mates. The expected proportions of seeds produced by clonal trees as a result of pollination by orchard clones, and by contaminating pollen originating from internal and external sources were estimated at 86.8%, 3.3% and 9.9%, respectively. Nematode-resistant seedlings of Japanese black pine were produced from surviving 2-yr seedlings that had previously been inoculated with pinewood nematode (Bursaphelenchus xylophilus). Without pollen contamination, the survival rate of seedlings produced by mating between resistant clones is expected to be 62.4%. However, in this orchard the figure was reduced to 57.5%, due to pollen contamination from both internal and external sources.

scholarly journals Researches on the Main Characteristics of Red Clover Seedlings and their Influence in

2012 ◽  
Vol 69 (1) ◽  
Author(s):  
Marioara GREBENIȘAN ◽  
Doru PAMFIL ◽  
Dorottya Alice DOMOKOS
Keyword(s):  
Plant Breeding ◽  
Seed Production ◽  
Red Clover ◽  
Production Level ◽  
Seed Crop ◽  
Binding Process ◽  
Lower Variability ◽  
Clover Seed ◽  
Number Of Seeds

Concerning the red clover breeding, it is essential to choose as genitors those varieties that possess good characteristics. In order to identify potential genitors, two red clover varieties were studied at Cluj-Napoca: Roxana, diploid variety and Napoca-tetra, tetraploid variety. The analyzed traits comprised the number of capitula/plant, number of seeds/capitulum and the binding process, under the aspect of their contribution to the seed crop and the interaction between those components, in order to provide important clues about di-and tetraploid red clover seed production, for plant breeding. The highest variability (s%=30) presented regarding the number of flowers/capitulum, diploid variety comparatively with a lower variability (s%=26) regarding the number of flowers number/capitulum, tetraploid varieties. Several traits were compared between di-and tetraploid red clover varieties in order to find genitors which can be used for creating new genotypes with high seed production level.

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