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1.
Within- and between-provenance variations in seed and seedling traits of Khaya senegalensis A. Juss were studied at INERA in Burkina Faso. Nursery grown seedlings from four provenances in Burkina Faso were used for the study. The studies revealed significant variability in all traits evaluated. Seed length and weight significantly varied among provenances and families within provenances, where Bopiel and Koyenga had the highest mean values. Height and root collar diameter of 1 year old seedlings significantly varied among families within provenances. Except leaf biomass ratio and carbon isotope ratio which varied significantly among provenances but not among families within provenances, all other seedling biomass traits—total plant biomass, stem biomass ratio, leaf biomass ratio, root biomass ratio, root shoot ratio, specific leaf area, and leaf area ratio were significantly affected by provenances and families within provenances. The magnitude of variation due to family effect ranged from 65 to 93 % for seed size traits, and from 4.5 to 17.8 % for seedling characters. Estimates of family heritability were moderate to high (0.67–0.95) for seed traits, but low to moderate (0.19–0.59) for seedling characters, indicating that much of the total variation in seed traits is due to the genetic effect. The two most prominent provenances, Koyenga and Bopiel, with higher seed size and greater seedling growth could be considered for an eventual K. senegalensis improvement program in Burkina Faso.  相似文献   

2.
The extent of genetic variation in seed and seedling traits of Trigonobalanus doichangensis, a rare and endangered tree in southwest China, was evaluated at the population level. Seeds were collected from four natural populations in the south and southwest Yunnan province, China. Significant differences (P < 0.05) between populations were observed in seed length, seed weight and seedling morphological characters. The analyses revealed that none of the seed and seedling traits had significant correlations with the geo-climatic variables of the populations. Among seed and seedling traits, significant correlations (P < 0.05) were discovered among seed length, seed weight and height of 30-day-old seedlings. Significant correlation (r = 1.00, P < 0.01) occurred also between the height and root collar diameter of 4-year-old seedlings. With the exception of seed width and seed germination percentage, 51–96% of total variation in other seed and seedling related traits was attributed to population effect, as determined by the broad sense heritability. In conclusion, these observations on variation in seed and seedling traits should be a reference point, when considering seed collection of this species for ex situ conservation and species restoration.  相似文献   

3.
Patterns of genetic variation in Cordia africana, a tropical timber species, were evaluated at the population level. Bulk seed samples were collected from six natural populations in Ethiopia and examined for variations in seed morphometric traits, seed germination, and seedling growth at nursery stage. Analysis of variance revealed significant differences among provenances in all studied attributes except root collar diameter after 4 months of growth. The provenance effect, as determined by broad sense heritability, was 71–98% for seed morphometric traits, 80% for germination capacity, 42% for germination energy, 57–58% for seedling height and 3–13% for root collar diameter. Seed weight showed a significant positive correlation with altitude and negative correlation with mean annual temperature of seed origin. Germination energy was significantly correlated with longitude and mean annual rainfall. Seedling parameters and geo-climatic variables of seed origin were fairly correlated. A significant intercharacter correlation was found between seed length and seed weight, between root collar diameter at the age of 4 months and seed length and weight, as well as between seedling height after 4 and 8 months of growth. It can be concluded that the observed patterns of variation will have implications for genetic resources conservation and tree improvement.  相似文献   

4.
The genetic variation in seed weight, seed number per kg and seedling traits was compared among eight Acacia senegal provenances originating from the clay plain (east) and sand plains (west) of the gum belt in Sudan. The main objective of this study was to identify germplasm sources of A. senegal that have a good seed germination capacity and seedling traits suitable for reforestation in the clay-soil part of the dryland gum belt in the Blue Nile region in Sudan. A specific objective was to tentatively explore the adaptive strategy of A. senegal populations. Seventeen-week-old seedlings were planted in the field at spacing of 3 m × 3 m, giving 100 trees per plot and replication; within a randomized complete block design with four replications. The experimental site was in the clay plain region. Seed variables showed significant differences. Clay plain provenances showed considerable variation in seed weight and seed number. They had the smallest seed weight but the highest seed number, while the sand (western) provenances had the largest seed weight but lowest seed number. Seedling branch number, root length, root to shoot ratio and shoot dry weight differed significantly among the provenances 12 weeks after germination. Clay provenances had the highest branch number and shoot dry weight but the shortest roots and lowest root to shoot ratio. This was interpreted as showing better adaptation to the site in these local provenances in comparison to those originating from the western sandy soil regions. High positive correlations were observed between seedling variables, such as root nodule and branch numbers; this could be used for early selection. The variation was greater between provenance groups than within them, suggesting that especially selection among groups would yield genetic gain.  相似文献   

5.
文冠果种子及苗期生长性状地理种源变异   总被引：1，自引：0，他引：1       下载免费PDF全文
[目的]研究不同种源文冠果(Xanthocerassorbifolium Bunge)的种子形态特征及在山东省安丘地区苗期性状差异,了解文冠果不同种源变异特征,为文冠果在山东安丘地区引种和遗传改良提供参考。[方法]以来自山东、河南、内蒙古、辽宁、黑龙江、河北、新疆、陕西等地的27个种源的文冠果种子为研究对象,对其种子形态指标进行测定,并在山东省安丘市开展种源试验。[结果]研究发现:不同种源间文冠果表型性状均存在极显著差异(P0.01),且这些差异可以稳定遗传(遗传力均大于0.9);苗期苗高与种源地降水、年均气温及地径与降水之间呈极显著正相关(P0.01),苗高与种源地纬度、年均日照及地径与年均日照呈极显著负相关(P0.01),种子长、种子宽、种皮厚均与海拔呈极显著负相关(P0.01)。[结论]文冠果表型性状存在丰富的变异,且受较强遗传控制;文冠果苗期性状变异主要受降水、年均气温、年均日照3个环境主导因子的影响,种子性状变异主要受海拔的影响。综合种源苗期生长状况,初步筛选出山东东营、山东安丘、内蒙古库伦、辽宁关山和辽宁海城5个适合安丘地区育苗的速生种源。  相似文献   

6.
Climate varies along altitudinal gradients and species performance may be affected in response to these variations. Climate change can modify these gradients and, at the lower limit of species distributions, individuals may become stressed and their general health and reproductive performance may decrease. Study and prediction of the effects of climate change on the distribution of species along these gradients is therefore necessary. Our model study species, Pinus pseudostrobus, is a widely distributed pine in Mexico, ranging from 1600 to 3200 masl in altitude. In order to explore changes in health condition and reproductive investment along an altitudinal gradient, ten reproductive trees were selected in each of four populations (at 2300, 2400, 2700 and 2900 masl). As a proxy of individual health, we conducted a rapid visual assessment for each tree, based on crown defoliation, dead branches and foliage discoloration. This stress condition index (SCI) ranges from zero to fifteen, and lower values indicate low stress and therefore better health conditions. We also evaluated reproductive (cone weight, number/weight of seeds) and progeny (germination/seedling growth) traits. In addition, the relationships between SCI and the reproductive/progeny traits were assessed. The lowest altitude population presented poor health, with higher values of SCI (mean ± SE = 6.3 ± 0.9) that reduced up to 4.8-fold in higher-altitude populations. Cone weight also differed among altitudes, with lighter cones in the lower population (mean ± SE = 38.2 ± 4.3 g), and 1.5-fold heavier cones found in the higher populations. In general, all of the reproductive/progeny traits differed among altitudes. The population of intermediate altitude (2700 masl) presented the highest values for all traits evaluated, indicating higher performance at this altitude. Finally, a negative relationship was found between stress condition and cone weight. Based on our results and climate change models and their predictions, an increase in physiological stress can be expected in individuals of low altitude populations. Furthermore, possible increases in pests and pathogens are likely to contribute to the decline of this population. It is therefore necessary to maintain efforts of stress condition assessment and population dynamics, as well as to permanently monitor the climate along altitudinal gradients.  相似文献   

7.
Cordia africana is a very important indigenous tree species for timber and other products and services in Ethiopia. Seed traits and seedling vigour of seeds from 12 provenances of the species were compared. Mean seed mass for each provenance was assessed for 1000 seeds in 10 replications, and seed length and width were measured for 100 seeds in four replications per provenance. Germination was assessed in a glasshouse taking 400 seeds from each provenance. Root collar diameter and height of 440 seedlings grown in a nursery for 290 days in Addis Ababa were measured. Seed length, seed width, seed mass, and shoot height and root collar diameter of seedlings showed significant differences (P < 0.001) among provenances. Correlation analysis between seed and seedling traits and environmental variables revealed significant positive correlations between seed width and germination percentage, seed width and altitude, seed width and longitude and seed length and latitude. Negative correlations were obtained between seed width and temperature, seed width and rainfall, seed mass and temperature, and germination and temperature of the seed source. As expected, differences in seed trait did not explain the variability in seedling vigour. Determining quantitative variations in seed traits and seedling vigour among provenances and the patterns along environmental gradients are essential for informing decisions on the tree improvement programme of the species.  相似文献   

8.
The altitudinal pattern of genetic variation in Pinus hartwegii Lindl. populations was explored for seedling height growth, frost damage, grass-stage, and phenological stage of the terminal shoot. A provenance test was conducted with open-pollinated seed from 13 populations collected along an altitudinal transect (3000–3600 m) at the National Park Pico de Tancítaro, Michoacán, center-west Mexico. Height growth of seedlings in a nursery was assessed at seven and 18 months of age. Frost damage at −15 °C was evaluated in laboratory at 18 months of age; proportion of plants that had left grass-stage and stage of shoot development was assessed at the age of 22 months. Significant differences among provenances (P < 0.0001) were detected for all of the evaluated characters. The variation among populations was structured as a moderate altitudinal cline, with populations from lower altitudes showing larger height growth in seedlings, larger proportion of frost damages, fewer seedlings in grass-stage and more seedlings with developed shoot, whereas in populations from higher altitudes, seedlings exhibiting shorter plant height, lower percentages of frost damage, more seedlings with unbroken grass-stage, and fewer seedlings with advanced shoot development were displayed. Options for seed and seedling movement along the altitudinal gradient are discussed under the scope of reforestation, aiming at ecological restoration, conservation of forest genetic resources, and assisted migration considering global warming. We suggest delineation of two altitudinal seed zones (Zone I: 3000–3350 m; Zone II: 3350–3700 m).  相似文献   

9.
Abstract

Intraspecific variability in responses to temperature and shade was studied at Champenoux, north-eastern France, with seedlings from five Polish provenances of silver fir (Abies alba Mill.). Acclimation of photosynthesis to temperature was investigated in seedlings exposed to 10, 25 and 35°C in a climate chamber for 1 week. During two growth seasons, a population of seedlings was grown in the nursery under four different irradiance regimens: 100, 48, 18 and 8% of natural irradiance. Maximum carboxylation rate (V cmax), maximum light driven electron flow (J max) and maximum net carbon dioxide assimilation rate (A max) measured at 25°C increased with population altitude. One week of exposure to 35°C caused discoloration and massive needle shedding. After 2 years’ acclimation to different levels of irradiance, a significant interprovenance variability was evidenced in growth, total biomass, biomass allocation and photosynthetic performance. This study provided evidence for the existence of functional variation among the examined provenances.  相似文献   

10.
The carob tree (Ceratonia siliqua L.) is widely used in arid and semi-arid areas of Mediterranean countries for industrial, agricultural and ornamental purposes. We wished to determine the variability of its morphological parameters in relation to its exploitation for commercial purposes. Thirteen cultivated and 15 spontaneous populations of C. siliqua from various edapho-climatic zones of Tunisia were compared to determine the variation in pod and seed parameters, for trees growing in situ, and in 2C nuclear DNA content (determined by flow cytometry), for seedlings grown from seeds collected in situ. Analysis of variance showed significant differences (P < 0.0001) between sites for fresh weight, length, width, internal and external thickness of pods, the pod length/width ratio, percentage of viable seeds and seed fresh weight. The mean pod fresh weights (range 8.63–36.03 g) of cultivated C. siliqua were significantly greater than those of spontaneous trees (7.70–19.39). Similarly, for other morphological characters (pod length, width and thickness and seed weight), the cultivated trees showed the highest mean values: 19.46 cm, 2.22 cm, 0.91 cm and 0.20 g, respectively. How this variability could be exploited for agronomic and commercial purposes is discussed. The variation of the examined morphological characters was not correlated with the quantity of DNA, since there were no significant differences in nuclear DNA content among the cultivated or spontaneous individuals. The mean 2C nuclear DNA content was 1.20–1.30 pg, indicating the trees to be diploid (2n = 24).  相似文献   

11.
Mature seeds of H. salicifolia, collected from five provenances (i.e. Hanuman Chatti, Helang, Lata, Rambara and Janggal Chatti) in west Himalaya, India, were treated with stratification (at 4°C for 15, 30 and 60 days) and in different concentrations of GA3 (5, 10, 20 mM), KNO3 (50, 100, 200 mM) and Thiourea (50, 100, 200 mM) solution to determine the variations in seed germination. Results reveal that the germination rates of seeds from different provenances under different pre-sowing treatments are significantly increased compared to those in control (24%–30%). The seeds treated with Thiourea (100 mM) have highest germination rate (76%–83% for different seed sources), followed by those (63%–71% for different seed sources) pretreated with stratification (4°C, 30 days). GA3 treatment significantly shortens the mean germination time (MGT) and improves seed germination percentage. Considering the practical applicability and cost effectiveness, thiourea (100 mM) and stratification (at 4°C) treatments for seed germination are recommended for mass multiplication through seeds of H. salicifolia in village/forest nurseries of the west Himalaya, India.  相似文献   

12.
Seed morphometric characters and oil content were studied in multiple-use plant, Calophyllum inophyllum L. of two countries, Australia (southern hemisphere) and Sri Lanka (northern hemisphere). Seven provenances were selected which included three from northern Australia and four from Sri Lanka. Twelve Candidate plus trees (CPTs) each were selected from 2 to 3 different locations within each provenance based on the morphometric and qualitative traits (GBH > 100 cm). Seed collection in both hemispheres was carried out from May to August 2008. Calophyllum inophyllum L. provenances showed a distinct hemisphere variation in their seed-related characters and oil content. All provenances differed significantly (P < 0.05) with one another in seed length. Seeds from Anuradhapura, Sri Lanka and seeds from Cardwell Australia recorded the highest (≈57%) and the lowest oil (≈31%) content respectively. Strong correlations were found between seed morphometric characters. Relatively weaker correlations were found between seed morphometric characters and oil content. Variations in seed-related characters were largely attributed by the provenance contribution which shows the significance of the effect of genetic variability on above mentioned seed related characters.  相似文献   

13.
[Objective]To compare the differences of seed morphological characters among provinces of Quercus variabilis Bl.,and explore the adaptive growth status of seedlings growing in the central distribution area. [Method]The seeds of 6 Q. variabilis provenances from six provinceswerecollected, and the seedlings were cultivated and transplanted to experimental field in the centre of natural distribution range (Wuhan Jiufeng National Forest Park), then the seed morphology and one-year seedling growth traitswere surveyed. [Result](1)There were significantor extremely significantdifferences among provenances in seed length, seed width, seed length/width ratio and 100-seed mass, the order of seed length among provenances was Beijing Provenance (22.28 mm),Hubei Provenance (22.10 mm), He'nan Provenance (20.80 mm), Shaanxi Provenance (19.57 mm), Yunnan Provenance (18.93 mm)and Liaoning Provenance (18.81 mm), the seed width of Beijing Provenance (19.71 mm) and Hubei Provenance (19.16 mm) was higher than that of the others, the seed length/width ratio of He'nan Provenance (1.38) was extremely significantly higher than that of the others; (2)There were significant or extremely significant differences among provenances in seedling height, ground diameter, leaf number, branching number and seedling height/ground diameter, the Beijing Provenance and Hubei Provenance were better in seedling height and leaf number, which were respectively 19.54 cm and 20.26 cm, 8.32 leaves and 9.50 leaves; (3)A decreasing trend with time for seedling growth traits among provenances was found; (4)There was a positive relationship between seed morphological characters and seedling growth traits except seed length/width ratio; the leaf number was significantly related to ground diameter and branching number and the seedling height and leaf number were closely related to the seed morphological characters; (5)It showed a decreasing trend with the growth time in the relationship between seedling growth traits and 100-seed mass. [Conclusion]The seedlings of Beijing Provenance and Hubei Provenance grew better in the experimental field which might be related to their larger seed mass, and the Yunnan Provenance in the south margin and the Liaoning Provenance in the north margin of distribution area of Q. variabilis grew weaker than the provenances in the centre of distribution area.With the effect of climate change, provenances in the margin of distribution area may lose in the community competition in the seedling stage if it cannot take advantage of its dispersal and settlement and affected by the disadvantage of growth and competition, so that the distribution and population renewal would surely be affected.  相似文献   

14.
Cordia africana is a very important indigenous tree species for timber and other products and services in Ethiopia.Seed traits and seedling vigour of seeds from 12 provenances of the species were compared.Mean seed mass for each provenance was assessed for 1000 seeds in10 replications,and seed length and width were measured for 100 seeds in four replications per provenance.Germination was assessed in a glasshouse taking 400 seeds from each provenance.Root collar diameter and height of 440 seedlings grown in a nursery for 290 days in Addis Ababa were measured.Seed length,seed width,seed mass,and shoot height and root collar diameter of seedlings showed significant differences(P0.001) among provenances.Correlation analysis between seed and seedling traits and environmental variables revealed significant positive correlations between seed width and germination percentage,seed width and altitude,seed width and longitude and seed length and latitude.Negative correlations were obtained between seed width and temperature,seed width and rainfall,seed mass and temperature,and germination and temperature of the seed source.As expected,differences in seed trait did not explain the variability in seedling vigour.Determining quantitative variations in seed traits and seedling vigour among provenances and the patterns along environmental gradients are essential for informing decisions on the tree improvement programme of the species.  相似文献   

15.
The variations in seed and pod traits, genetic superiority and genetic divergence were evaluated for a Clonal Seed Orchard (CSO) of Dalbergia sissoo Roxb. at Bithmera, India consisting of 20 clones from different agro-climatic conditions of four northern states (Uttar Pradesh, Uttarakhand, Haryana and Rajasthan). The seeds and pods of various clones in the orchard exhibited significant variability in size, weight and other characters. Significant positive correlations were observed between seed length and seed width (p<0.05), seed length and seed thickness (p<0.01), seed length and seed weight (p<0.01), seed thickness and seed weight (p<0.01), seed length and germination value (p<0.05). The genetic parameters for seed and pod traits also showed a wide range of variations in the orchard. Heritability values were found to be over 50 percent for most of the seed and pod traits. Seed weight, seed length and seed thickness showed high heritability values coupled with maximum genetic gain for these characters. Ward’s minimum variance dendrogram of clones of D. sissoo showed three distinct clusters; cluster 1 was the largest with 12 better clones whereas cluster 2 and 3 consisting of seven moderate clones and one poor clone, respectively. Mean cluster values showed sufficient variation among the clusters for seed weight, germination value and seed length. The possible hybridization between best clones of cluster 1 to the disease resistant clone of cluster 2 (resistant against deadly Gandoderma lucidum root rot disease of D. sissoo) is also suggested for further breeding programmes of the species. The deployment of clone 194 (better performed and disease resistant) is also recommended in future plantation programmes of D. sissoo in northern India.  相似文献   

16.
This study represents a geographical approach to morphological variation of cones, needles and seeds in natural dragon spruce (Picea asperata Mast.) populations across western China and the relationship between morphological traits and weather variation for the origins of populations. Significant differences were found for all cone, needle and seed traits among populations and trees within populations. The coefficients of variation in 2 higher latitude populations were higher than those in other populations in all traits except for needle width and seed width. Fairly high within-population variability was also detected for cone dry weight, seed dry weight and needle traits in this study. Cone length, cone width, cone dry weight, seed scale length, seed scale width and seed wing length were strongly positively intercorrelated. Seed length and seed dry weight showed a significantly positive correlation with seed wing length. And needle width showed a significant negative correlation with cone traits, seed scale length, seed wing length and seed length. The higher the annual mean temperature, the higher the average cone length. This study also revealed a negative linear dependence on latitude: the higher the latitude, the lower the population average seed length. Seed dry weight was positively and linearly related with altitude.  相似文献   

17.
Due to the expected increases of number and intensity of summer droughts in Central Europe the identification of drought tolerant ecotypes becomes more important in future forestry. A common garden experiment with seedlings of Fagus sylvatica provenances from the center (Germany) and eastern margin (Poland) of the species’ distribution range was conducted. Responses of morphological, physiological, chemical and growth parameters to three drought treatments were analyzed. Relative growth rates of the marginal provenance were lower as compared to the central provenance. The marginal seedlings showed a tendency to higher total biomasses because of higher seed masses. In both provenances drought decreased biomass production and root/shoot ratio which was lower in the central provenance. A lower specific root area of the marginal provenance indicated a better adaptation to low xylem water potentials. Under moderate drought, lower leaf δ13C signatures may indicate lower stomatal limitation (or a reduced rate of CO2 assimilation) in the marginal provenance. We conclude that marginal beech provenances may exhibit a better drought adaptation.  相似文献   

18.
以引进欧洲垂枝桦不同种源为对象,并以本地白桦种源作为对照,研究引进欧洲垂枝桦不同种源的种子形态特征、发芽特性和在黑河地区的苗期生长表现。结果表明:引进欧洲垂枝桦不同种源在种子长度、种子宽度、种翅长度、种翅宽度、千粒重、发芽率、发芽势、发芽指数、活力指数、苗高、地径、地上生物量、地下生物量和全株生物量存在显著差异,而且引进欧洲垂枝桦不同种源这些指标都显著高于本地白桦对照种源,综合分析表明,引进欧洲垂枝桦新西伯利亚种源在种子形态特征、发芽特性和在黑河地区的苗期生长表现均优,可作为黑河地区欧洲垂枝桦育苗的首选种源。  相似文献   

19.
The extent of genetic variation in seed length, width, thickness, weight and germination percentage and seedling traits among and within 12 African provenances of Faidherbia albida was examined. The regional provenances showed a consistent variation in seed length, seed width and seed weight: the southern African provenances had the largest seeds and west African provenances the smallest. Seedling height, stem collar diameter and true leaf number differed (P = 0.05) among the provenances 90 days after germination. The seedlings from west Africa were shorter, had smaller stem collar diameter and fewer leaves. In contrast, the southern and east African provenances had taller seedlings with bigger seedling diameter and more leaves per seedling. Seedling traits did not show clear-cut divisions between southern and east African provenances, but the west African provenances formed a distinct group. Positive correlations were found in some of the seed characteristics and seedling height among provenances, which could be an important criterion for early provenance selection. Greater variation was observed for seed and seedling traits among than within provenances suggesting that selection among provenances might result in rapid genetic gain for the traits studied. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

20.
美国栎属种源引种、变异研究:种子及苗期生长变异   总被引：12，自引：4，他引：8  
对从美国３个州（宾夕法尼亚、纽约和田纳西州）引进的栎属３个树种北方红栎、柳叶栎和红栎的２１个种源进行了两次播种和容器育苗试验。初步掌握了栎属种子砂床播种、芽苗移栽、容器育苗的关键技术。对栎属种子的发芽、芽苗和苗木的生长过程等有了一定的了解。发现栎属不同树种间和种内种源、家系间在种子体积、千粒重、发芽率、３０ｄ萌叶率和苗高生长等性状均存在极显著变异,试验数据表明种子体积北方红栎为大（其中宾夕法尼亚州家系１７２最大）,其次是红栎和柳叶栎。千粒重以北方红栎为重（其中宾夕法尼亚州家系１７２最重）,其次是红栎和柳叶栎。发芽率为北方红栎最高（其中宾夕法尼亚州家系１９１为１００％）,其次是红栎和柳叶栎。３０ｄ萌叶率和苗高生长以柳叶栎为高（田纳西州种源９７０１ＴＮ最高）,其次是红栎和北方红栎。在种间和种内不同种源、家系间种子千粒重与年终苗高生长相关不显著。  相似文献   

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