Effects of stand density on outcrossing rate in two Norway spruce (Picea abies) populations

1991 ◽  
Vol 69 (12) ◽  
pp. 2704-2708 ◽  
Author(s):  
M. Morgante ◽  
G. G. Vendramin ◽  
P. Rossi
Keyword(s):  
Picea Abies ◽  
Mating System ◽  
Norway Spruce ◽  
Stand Density ◽  
Major Effect ◽  
Outcrossing Rate ◽  
High Density ◽  
Low Density ◽  
The Mean ◽  
Key Words Mating System

The mating system was investigated in two neighbouring Norway spruce (Picea abies (L.) Karst.) populations with markedly different stand densities. The amount of outcrossing was estimated using open-pollinated array data at four enzyme loci. Multilocus estimates of the proportion of viable progeny owing to outcrossing were 0.956 and 0.955 for the low- and high-density stand, respectively, indicating that the large reduction in stand density had no impact on outcrossing rates. The multilocus estimate was higher than the mean single-locus estimate only for the low-density stand. The lowering of the mean estimate in the low-density stand is probably a consequence of the clustering of related individuals. The regression of pollen allele frequencies on ovule genotype, which is a direct measure of the effective selfing caused by consanguineous matings, had a significant coefficient for the low-density stand and a nonsignificant one for the high-density stand. This obvservation confirms that the major effect of low-stand density in Norway spruce is the occurrence of consanguineous matings. Key words: mating system, outcrossing rate, inbreeding, Norway spruce, stand density.

scholarly journals Life at the margin: the mating system of Mediterranean conifers

Web Ecology ◽  
2008 ◽  
Vol 8 (1) ◽  
pp. 94-102 ◽  
Author(s):  
G. Restoux ◽  
D. E. Silva ◽  
F. Sagnard ◽  
F. Torre ◽  
E. Klein ◽  
...  
Keyword(s):  
Mating System ◽  
Stand Density ◽  
High Density ◽  
Published Data ◽  
Mixed Mating ◽  
Low Density ◽  
Selfing Rate ◽  
Water Regimes ◽  
Single Tree ◽  
Mature Stand

Abstract. Mixed mating, where a single tree progeny results from a mixture of selfing and outcrossing, is widespread in conifers and could be an evolutionary advantage at ecological margins when mating partners become scarce. This study analyzes how the mating system responds to bioclimate and density variations. We surveyed published data on the mating system of Abies, Picea and Pinus species when information on bioclimate and stand density was available. Our survey revealed that Mediterranean species demonstrate a lower selfing rate than other species and that the proportion of selfed versus outcrossed progeny is not fixed within species. The highest variability in mating types within populations was found when stand density was the most variable. To show how density affects the proportion of selfed versus outcrossed progeny, we used isozymes to genotype single tree seeds from a marginal Abies alba forest in Mediterranean France (Mont Ventoux) where low-to high-density stands are found. We then tested the adaptive potential of the different high and low density progenies by sowing them under controlled nursery conditions and measuring germination rate and seedling survival after 4 yr under 3 different water regimes. Although the mean value of outcrossing rate was typical for mixed mating conifers (tm = 0.85), individual outcrossing rates varied from 0.05 to 0.99 and were strongly correlated with stand type and density (tm from 0.87 in high-density to 0.43 in low-density marginal stands). Significantly fewer seeds from the low density marginal stand germinated (32% vs. 53% in the high density mature stand), although seedlings from the marginal stand had a better 4-yr survival (81%) than seedlings from the high-density mature stand (63%) when the three water regimes (from least to most stressful) were averaged. Trees from low density stands may be at a selective disadvantage because they produce more selfed progeny than trees from high-density stands. However, selfed seeds may be purged early on (at the embryo stage) and the remaining seeds tend to produce seedlings with better fitness. Variability of the selfing rate might thus be an adaptive strategy for species in highly contrasted environments where selection of both reproductive assurance and avoidance of inbreeding depression may be density dependent.

scholarly journals Hypertriglyceridemia is associated with the incidence of preeclampsia

2018 ◽  
pp. 218-221
Author(s):  
Intje S Dahlan ◽  
Mardiah Tahir ◽  
Efendi Lukas ◽  
St. Maisuri T Chalid
Keyword(s):  
High Density Lipoprotein ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Mean Value ◽  
High Density ◽  
University Teaching ◽  
Low Density ◽  
Hospital Department ◽  
Exact Test ◽  
The Mean

Abstract Objective: to find out  the correlation between lipid profille at trimester II of pregnancy and the incidence.of preeclampsia Method : The research  was conducted in the Polyclinic of Hasanuddin University Teaching Hospital, Department of Obstetrics and Gynecology of the Faculty of Medicine, and it network in Makassar city from March, 2015 through March, 2016. The research used was the prospective cohort design. Results : The examination of the lipid levels of 115 pregnant mothers, aged 24-28 weeks. The mothers were then observed whether they experienced preeclampsia up to the time they gave birth or not. In the end, 8 subjects (6.9%) experienced preeclampsia and 107 subjects (93.1%) have no preeclampsia. The statistical analyses used Fisher’s Exact test and Mann Whitney test. The research results indicated that the mean value of the total cholesterol and Low Density Lipoprotein (LDL) was higher in the preeclampsia group compared to the non-preeclampsia group: 267.37 ± 64.12 : 238 ± 37.98; 177.38 ± 55.38 : 157.24 ± 35.08 (p>0.05). The mean value of High Density Lipoprotein (HDL) was lower in the preeclampsia group compared to the non-preeclampsia group: 64.75 ± 14.64 : 67.86 ± 16.72 (p>0,05). The mean value of trigliserida in preeclampsia group was significantly higher (19,5%) compared thanin the non-preeclampsia group: 260.12 ± 58.86 vs 209.14 ± 65.10 (p=0,027). Conclusion : The hypertrigliseridemia was correlated with the preeclampsia incidence. Keywords:preeclampsia, lipid profile, trimester II of pregnancy   Abstrak Tujuan: mengetahui hubungan antara profil lipid kehamilan trimester II dengan kejadian preeklamsia. Metode : Penelitian dilaksanakan di Poliklinik RS jejaring pendidikan Departemen Obstetri dan Ginekologi Fakulltas Kedokteran Universitas Hasanuddin dan Poliklinik Kesehatan Ibu dan Anak di beberapa Puskesmas Kota Makassar selama Maret 2015 sampai dengan Maret 2016. Rancangan penelitian yang digunakan adalah prospektif  kohort. Hasil: dari 115 ibu hamil dilakukan pemeriksaan  kadar lipid, 115 ibu hamil pada usia kehamilan 24 – 28 minggu, kemudian diamati apakah subyek mengalami preeklamsia hingga proses persalinan. Terdapat delapan subyek (6,9%) berkembang menjadi preeklampsia dan 107 subyek tidak preeklamsia. Data dianalisis secara statistik dengan menggunakan uji Fisher’s Exact dan uji Mann Whitney. Hasil penelitian menunjukkan bahwa nilai mean kolesterol total dan Low Density Lipoprotein (LDL) lebih tinggi pada kelompok preeklampsia dibandingkan kelompok tidak preeklamsia, yaitu 267,37 ± 64,12 : 238,01 ± 37,98; 177,38 ± 55,38 : 157,24 ± 35,08 (p>0,05). Nilai mean High Density Lipoprotein (HDL) lebih rendah pada kelompok preeklamsia dibandingkan tidak preeklamsia yaitu 64,75 ± 14,64 : 67,86 ± 16,72 (p>0,05). Nilai mean trigli seri daripada kelompok preeklamsia secara signifikan lebih tinggi 19,5 % dibandingkan kelompok tidak preeklamsia, yaitu 260,12 ± 58,86 : 209,14 ± 65,10 (p=0,027). Kesimpulan : Hiper trigli seridemia berhubungan dengan kejadian preeklamsia. Kata kunci : preeklamsia, profil lipid, kehamilan trimester II    

Determination of high-density lipoprotein phospholipids in serum.

1980 ◽  
Vol 26 (9) ◽  
pp. 1275-1277 ◽  
Author(s):  
Y Yamaguchi
Keyword(s):  
High Density Lipoprotein ◽  
Density Lipoprotein ◽  
Mean Value ◽  
High Density ◽  
High Density Lipoproteins ◽  
Low Density ◽  
Very Low Density Lipoproteins ◽  
Color Development ◽  
The Mean

Abstract I describe a method for measuring high-density lipoprotein phospholipids. Magnesium chloride and dextran sulfate are used to precipitate all low-density and very-low-density lipoproteins. The supernate contains only high-density lipoproteins, the phospholipid concentration of which is determined by an enzymic method. The precision of the method (CV) is 2.35% (10 repeated assays), and the mean value for HDL-phospholipids was 1006 (SD 248) mg/L for 30 apparently healthy subjects. I used electrophoresis and enzymic color development to confirm the presence of HDL-phospholipids. Results are compared with those obtained by an ultracentrifugation method.

scholarly journals Growth, Biomass Production and Root Development of Chinese fir in Relation to Initial Planting Density

Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 236 ◽  
Author(s):  
Taimoor Farooq ◽  
Wenjing Wu ◽  
Mulualem Tigabu ◽  
Xiangqing Ma ◽  
Zongming He ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Biomass Production ◽  
Stand Density ◽  
Tree Height ◽  
Root Systems ◽  
Chinese Fir ◽  
High Density ◽  
Planting Density ◽  
Low Density ◽  
Intermediate Density

Chinese fir (Cunninghamia lanceolata (Lamb) Hook) is a commercially valuable timber species that is widely planted in southern China and accounts for 6.1% of the global plantation forests. However, appropriate planting density that ensures high plantation productivity is largely unexplored in this species. The aim of the study was to examine tree growth, biomass production, and its allocation among different organs in relation to initial planting density, and to examine whether planting density has an impact on root development. Mortality, diameter at breast height and tree-height of all trees were determined and measured in wider (2.36 × 2.36 m), intermediate (1.83 × 1.83 m) and narrow (1.44 × 1.44 m) spacing with stand density of 1450 trees ha−1, 2460 trees ha−1 and 3950 trees ha−1, respectively. In each stand, three plots of 20 × 20 m at a distance of 500 m were delineated as the sampling unit. Biomass was determined by destructive sampling of trees in each stand and developing allometric equations. Root morphological traits and their spatial distribution were also determined by carefully excavating the root systems. The results showed an increase in diameter of trees with decreasing stand density while tree height was independent of stand density. Biomass production of individual trees was significantly (p < 0.05) less in high-density stand (32.35 ± 2.98 kg tree−1) compared to low-density stand (44.72 ± 4.96 kg tree−1) and intermediate-density stand (61.35 ± 4.78 kg tree−1) while stand biomass production differed significantly in the order of intermediate (67.63 ± 5.14 t ha−1) > high (57.08 ± 3.13 t ha−1) > low (27.39 ± 3.42 t ha−1) stand density. Both average root length and root volume were significantly (p < 0.05) lower in the high-density stand than stands with low and intermediate density. Analysis of spatial distribution of root systems revealed no overlap between roots of neighboring trees in the competition zone in low-density stand, a subtle overlap in the intermediate density stand and larger overlap in the high-density stand. It can be concluded that better growth and biomass production in intermediate density stand could be explained by better root structural development coupled with minimal competition with understory vegetation and between trees; thus intermediate stand density can be optimal for sustaining long-term productivity and may reduce the management cost in the early phase of the plantation.

Effects of Gravel Size, Egg Depth, and Egg Density on Intragravel Movement and Emergence of Coho Salmon (Oncorhynchus kisutch) Alevins

1970 ◽  
Vol 27 (7) ◽  
pp. 1191-1199 ◽  
Author(s):  
L. M. Dill ◽  
T. G. Northcote
Keyword(s):  
Environmental Variables ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
High Density ◽  
Low Density ◽  
Gravel Size ◽  
Egg Density ◽  
The Mean

In experimental aquaria with large gravel (3.2–6.3 cm), vertical and lateral movements of coho salmon (Oncorhynchus kisutch) alevins were more extensive and area utilized per alevin was greater than in small gravel (1.9–3.2 cm). At low density (50 per aquarium) the alevins moved farther towards the inlet, but the mean area occupied per alevin was the same as that at high density (100 per aquarium). Burial depths tested (20 and 30 cm) had no significant effect on vertical or lateral movements or on area utilized per alevin. Alevin orientation in the gravel, survival to emergence, and timing of emergence were not affected by any of the environmental variables examined.

Low-density Ceratocystis polonica inoculation of Norway spruce (Picea abies) triggers accumulation of monoterpenes with antifungal properties

2013 ◽  
Vol 133 (4) ◽  
pp. 573-583 ◽  
Author(s):  
Metka Novak ◽  
Andreja Urbanek Krajnc ◽  
Ljerka Lah ◽  
Neja Zupanec ◽  
Nada Kraševec ◽  
...  
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Low Density ◽  
Antifungal Properties ◽  
Ceratocystis Polonica

scholarly journals Erratum to: Low-density Ceratocystis polonica inoculation of Norway spruce (Picea abies) triggers accumulation of monoterpenes with antifungal properties

2014 ◽  
Vol 133 (4) ◽  
pp. 585-585
Author(s):  
Metka Novak ◽  
Andreja Urbanek Krajnc ◽  
Ljerka Lah ◽  
Neja Zupanec ◽  
Nada Kraševec ◽  
...  
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Low Density ◽  
Antifungal Properties ◽  
Ceratocystis Polonica

Infection of advance regeneration of Norway spruce by Heterobasidion parviporum

2001 ◽  
Vol 31 (6) ◽  
pp. 937-942 ◽  
Author(s):  
Tuula Piri ◽  
Kari Korhonen
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Root Rot ◽  
Heterobasidion Annosum ◽  
Advance Regeneration ◽  
Mean Size ◽  
The Mean ◽  
Vegetative Spread ◽  
Overstory Trees

The incidence of Heterobasidion root rot in the advance regeneration of Norway spruce (Picea abies (L.) Karst.) was studied in nine stands at four different localities in southern Finland. The mean age of the unthinned advance regeneration on the 17 sample plots ranged from 14 to 44 years. On infested plots, the proportion of Norway spruce infected by Heterobasidion varied from 22.2 to 75.0% (mean 52.5%) in the overstory and from 1.8 to 68.2% (mean 21.1%) in the advance regeneration. The corresponding values on healthy-looking control plots were 0–6.7% (mean 5.9%) and 1.3–3.9% (mean 2.4%), respectively. Of the 138 Heterobasidion genets identified, 98.5% belonged to Heterobasidion parviporum Niemelä & Korhonen and 1.5% to Heterobasidion annosum (Fr.) Bref. s.s. The incidence of Heterobasidion root rot in advance regeneration was positively correlated with the mean size and age of the advance regeneration and the proportion of infected trees in the overstory and negatively correlated with the regeneration density. Vegetative spread through root contacts from overstory trees to the surrounding regeneration accounted for at least 53% of the Heterobasidion infections in the advance regeneration. The origin of the rest of the infections in advance regeneration remained unclear, but at least part of them may have started from spore infection on injured or dead roots. Our results suggest that, on sites infected by H. parviporum, advance growth of Norway spruce should not be used for regeneration even though the spruces look healthy and show no external signs of infection.

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