scholarly journals Flowering Phenology in Teak Seed Orchards - Genetic Variation, Measurement and Implications to Seed Orchard Fertility

10.5772/35658 ◽  
2012 ◽  
Author(s):  
Vasudeva Ramesh ◽  
Rajesh Gunag
Keyword(s):  
Genetic Variation ◽  
Seed Orchard ◽  
Flowering Phenology ◽  
Seed Orchards

scholarly journals Variation in Floral Phenological Synchronization in a Clonal Seed Orchard of Pinus tabuliformis in Northeast of China

2012 ◽  
Vol 61 (1-6) ◽  
pp. 133-142 ◽  
Author(s):  
Wei Li ◽  
Xiaoru Wang ◽  
Yue Li
Keyword(s):  
Genetic Control ◽  
First Generation ◽  
Seed Orchard ◽  
Flowering Phenology ◽  
Seed Orchards ◽  
Clonal Seed Orchard ◽  
Pinus Tabuliformis ◽  
Seed Harvest ◽  
Initial Seed ◽  
Northeast Of China

Abstract Flowering phenology in an orchard is a crucial factor affecting the gene exchange among clones and consequently changing genetic composition of the seed crop. Pinus tabuliformis is now at the crucial period from first generation clonal seed orchards to advanced generation seed orchards in China. In this study, variation and stability in floral phenological synchronization of all the clones and possible mating pairs, in terms of an index of phenological overlap, were observed in a first generation clonal seed orchard which located in northeast of China. Results showed that significant variations occurred in the clones and mating pairs. This kind of variation was apparently related with temperature and humidity of the research site. With increasing age, levels of flowering synchronization were likely to rise in the clones and mating pairs. In general, the average flowering synchronization of male parents was slightly higher than that of female parents, female management in a seed orchard should be paied more attention. Flowering time was under strong genetic control and this genetic control was stronger in the female flowering process than of the males in terms of board sense heritability and year to year correlation analysis. Flowering synchronization of female parents was positively correlated between most years and can be a reliable reference for early and late predication in Pinus tabuliformis seed orchard during stage of initial seed harvest to stable seed production. According to their average levels of flowering synchronization, 49 clones in the first generation clonal seed orchard were divided into 11 different groups. Results of this paper provided the basic information for first generation seed orchard management and advanced seed orchard establishment of Pinus tabuliformis.

Field performance and early test results of offspring from two Norway spruce seed orchards containing clones transferred to warmer climates

2007 ◽  
Vol 37 (3) ◽  
pp. 515-522 ◽  
Author(s):  
Tore Skrøppa ◽  
Ketil Kohmann ◽  
Øystein Johnsen ◽  
Arne Steffenrem ◽  
Øyvind M. Edvardsen
Keyword(s):  
Norway Spruce ◽  
Field Performance ◽  
Seed Orchard ◽  
Field Trials ◽  
Climatic Conditions ◽  
Test Results ◽  
Seed Orchards ◽  
Low Altitude ◽  
Natural Stands ◽  
Seed Crops

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.

scholarly journals Studies on the Pollination Characteristics and Pollination Level of Chinese fir Seed Orchard

2004 ◽  
Vol 53 (1-6) ◽  
pp. 7-11 ◽  
Author(s):  
Z. Zhuowen
Keyword(s):  
Accumulation Rate ◽  
Pollen Grains ◽  
Seed Orchard ◽  
Distribution Patterns ◽  
Chinese Fir ◽  
Female Cone ◽  
Bottom Part ◽  
Male And Female ◽  
Seed Orchards ◽  
Male Cone

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.

scholarly journals Genetics and expected selection gain for growth traits in Eugenia dysenterica DC. populations

Bragantia ◽  
2009 ◽  
Vol 68 (3) ◽  
pp. 629-637 ◽  
Author(s):  
Ananda Virginia de Aguiar ◽  
Roland Vencovsky ◽  
Lázaro José Chaves ◽  
Mara Fernandes Moura ◽  
Lizz Kezzy de Morais
Keyword(s):  
Genetic Variation ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Block Design ◽  
Genetic Material ◽  
Germplasm Collection ◽  
Seed Orchard ◽  
Seedling Seed Orchard ◽  
Randomized Block Design ◽  
Eugenia Dysenterica

The objective of this study was to estimate genetic parameters of quantitative traits in a living germplasm collection of Eugenia dysenterica. The genetic material consisted of 110 progenies derived from 10 natural Eugenia dysenterica subpopulations sampled in the southeastern region of the state of Goiás. The experiment was established in a complete randomized block design, with 110 treatments, four replications and one tree per plot. The study variables were total height, stem diameter and respective growth rates. After the analysis of variance some genetic parameters were estimated. The levels of genetic variation in the collection were high and the highest proportion was found within subpopulations. Highest coefficients of heritability and genetic variation were observed in subpopulations from the counties Catalão, Três Ranchos, Cristalina and Senador Canedo. Considering the promising expected progress for growth traits, this collection can be converted into an unrogued seedling seed orchard, aiming the production of improved seed.

scholarly journals Comparison of Genetic Diversity in Naturally Regenerated Norway Spruce Stands and Seed Orchard Progeny Trials

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 926 ◽  
Author(s):  
Dainis Ruņģis ◽  
Solveiga Luguza ◽  
Endijs Bāders ◽  
Vilnis Šķipars ◽  
Āris Jansons
Keyword(s):  
Genetic Diversity ◽  
Norway Spruce ◽  
Gene Diversity ◽  
Seed Orchard ◽  
Seed Orchards ◽  
Spruce Stands ◽  
Ssr Loci ◽  
Naturally Regenerated Stands ◽  
Average Gene ◽  
Environmental Events

Forest ecosystems in Europe are expected to experience changes in temperature and water regimes associated with increased risks of extreme environmental events and disasters. Genetic diversity and relatedness has been linked to resilience of forest stands and landscapes. Genetic diversity indicators were compared between a Norway spruce population naturally regenerated after extensive windthrow and Norway spruce progeny populations derived from two seed orchards. In addition, genetic diversity in an undisturbed stand in a long established national park and a spruce genetic resource stand were analyzed. Populations were genotyped at 11 simple sequence repeat (SSR) loci. Average genetic diversity indicators were similar across populations. However, the total number of alleles, average number of alleles over all loci, effective number of alleles, average gene diversity, and average allelic richness were highest in the naturally regenerated population and lowest in one of the seed orchard progeny populations. The genetic diversity in progeny from seed orchards used for stand renewal is comparable to the genetic diversity in naturally regenerated stands. However, fluctuations in seed production between years can have a large impact on genetic diversity in seed orchard progeny. The use of improved Norway spruce germplasm deployed via clonal seed orchards for forest renewal can maintain similar levels of genetic diversity compared to naturally regenerated stands, while also increasing production and timber quality.

scholarly journals Genetic variation, mating patterns and gene flow in a Pinus pinaster Aiton clonal seed orchard

2008 ◽  
Vol 65 (7) ◽  
pp. 706-706 ◽  
Author(s):  
Lúcia Fernandes ◽  
Margarida Rocheta ◽  
Jorge Cordeiro ◽  
Sandra Pereira ◽  
Sophie Gerber ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Gene Flow ◽  
Pinus Pinaster ◽  
Seed Orchard ◽  
Mating Patterns ◽  
Clonal Seed Orchard

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.

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.

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