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1.
为筛选滇南亚高山的巨桉(Eucalyptus grandis)优良品系,对53月生的巨桉11种源173家系的生长性状进行分析。结果表明,所有生长性状在种源和家系间均呈极显著差异;胸径、树高、单株材积、干形、分枝和冠幅的表型和遗传变异系数分别为26.90%~28.84%、23.84%~25.28%、62.34~67.55、13.04%~25.62%、13.04%~25.41%和35.07~39.93,各性状种源遗传力为0.94~0.96,家系遗传力为0.88~0.95。相关分析表明,胸径与树高、单株材积、干形和冠幅呈极显著正相关,树高与其他性状均呈极显著正相关关系,干形与分枝的相关系数为0.70,冠幅与干形和分枝均呈负相关关系(r2=-0.03)。单株材积的遗传增益始终最大,以5%为入选率时,遗传增益高达66.11%;入选率不同,胸径与树高、干形与分枝的遗传增益的变化趋势基本相同,但不同性状的遗传增益值的排序发生变化。以10%为入选率,经综合指数选择有17个家系入选,均来自1号(昆士兰Copperlode)、4号(昆士兰Koombooloomba)、6号(昆士兰Copperlode Falls Dam)、7号(昆士兰Bambaroo)、9号(福建天马东溪)和11号(四川乐山)种源,2号(昆士兰Ravenshoe)和8号(昆士兰Tully Gorge National Park)种源表现最差,排前6名的家系为289号、283号、2号、42号、121号和82号,也分别分布在入选种源中,说明入选家系不仅生长优良而且遗传多样性比较丰富。  相似文献   

2.
巨桉种源/家系综合选择研究   总被引:3,自引:0,他引:3  
为选择巨桉(Eucalyptus grandis)优良种源,对其13个种源177个家系性状进行遗传分析。结果表明,22月生巨桉除生长量在区组间差异显著外,其他性状在种源、家系和区组间均存在极显著的差异;50月生时各性状差异均达极显著水平。50月生时,单株材积位于前四的种源分别是2号(来自昆士兰州Copperlode)、3号(来自昆士兰州Ravenshoe)、1号(来自昆士兰州N W Townsille)和11号(来自四川省黑龙滩)。50月生时,有78个家系的单株材积增长量超过总体家系平均值(0.08 m3),位于前三的家系是分别为2号(来自2号种源)、156号(来自福建天马东溪的10号种源)和93号(来自昆士兰州Bambaroo的8号种源)。50月生巨桉的胸径、树高、单株材积、干形、分枝和冠幅的遗传力分别为0.56、0.91、0.73、0.67、0.64和0.76;这些性状的表型变异系数分别为26.64%、29.37%、64.41%、17.58%、15.26%和45.80%;遗传变异系数分别为25.94%、24.30%、60.97%、28.59%、26.07%和42.96%。相关性分析表明,冠幅和分枝呈较小的负相关,其余各性状间均呈正相关性。结合生长指标和形质指标,最终筛选出4个优良种源和18个优良家系。  相似文献   

3.
Most temperate forest tree species will suffer important environmental changes as result of the climate change. Adaptiveness to local conditions could change at different sites in the future. In this context, the study of intra-specific variability is important to clarify the singularity of different local populations. Phenotypic differentiation between three beech provenances covering a wide latitudinal range (Spain/ES, Germany/DE and Sweden/SE), was studied in a greenhouse experiment. Non-target leaf metabolite profiles and ecophysiological response was analyzed in well-watered and water stressed seedlings. There was a provenance-specific pattern in the relative concentrations of some leaf metabolites regardless watering treatment. The DE and SE from the center and north of the distribution area of the species showed a clear differentiation from the ES provenance in the relative concentration of some metabolites. Thus the ES provenance from the south maintained larger relative concentration of some organic and amino acids (e.g. fumaric and succinic acids or valine and isoleucine), and in some secondary metabolites (e.g. kaempferol, caffeic and ferulic acids). The ecophysiological response to mild water stress was similar among the three provenances as a consequence of the moderate water stress applied to seedlings, although leaf N isotope composition (δ15N) and leaf C:N ratio were higher and lower respectively in DE than in the other two provenances. This would suggest potential differences in the capacity to uptake and post-process nitrogen according to provenance. An important focus of the study was to address for the first time inter-provenance leaf metabolic diversity in beech from a non-targeted metabolic profiling approach that allowed differentiation of the three studied provenances.  相似文献   

4.
不同种源樟树叶片形态特征及生长差异分析   总被引:1,自引:0,他引:1  
为了解不同种源樟树叶片形态特征和生长差异,该文以30个种源樟树为研究对象,对其叶长、叶宽、叶柄长、周长、叶面积、长宽比、形态因子、株高、地径等指标进行测定和差异性分析.结果表明:(1)30个种源间叶片性状的变异系数为3.88%~16.14%,显示不同种源樟树叶片形态特征存在显著差异;叶长、叶宽、叶柄长、周长、面积、叶厚...  相似文献   

5.
Arjen Biere 《Plant and Soil》1996,182(2):313-327
Plant species from unproductive or adverse habitats are often characterized by a low potential relative growth rate (RGR). Although it is generally assumed that this is the result of selection for specific trait combinations that are associated with a low rate of net biomass accumulation, few studies have directly investigated the selective (dis-)advantage of specific growth parameters under a set of different environmental conditions. Aim of the present study was to quantify the impact of inherent differences in growth parameters among phenotypes of a single plant species, Lychnis flos-cuculi, on their performance under different soil nutrient conditions. Growth analysis revealed significant variation in RGR among progeny families from a diallel cross between eight genotypes originating from a single population. Differences in RGR were due to variation in both leaf area ratio (LAR) and in net assimilation rate (NAR). A genetic trade-off was observed between these two components of growth, i.e. progeny families with high investment in leaf area had a lower rate of net biomass accumulation per unit leaf area. The degree of plasticity in RGR to nutrient conditions did not differ among progeny families. Inherent differences in growth parameters among progeny families had a significant impact on their yield in competition with Anthoxanthum odoratum and Taraxacum hollandicum. In nutrient-rich conditions, progeny families with an inherently high leaf weight ratio (LWR) achieved higher yield in competition, but variation in this trait could not explain differences in competitive yield under nutrient-poor conditions. Inherent differences in growth parameters among progeny families were poorly correlated with differences in survival and average rosette biomass (a good predictor of fecundity) among these progeny families sown in four field sites along a natural gradient of soil fertility. In the more productive sites none of the growth parameters was significantly correlated with rosette biomass, but in the least productive site progeny families with an inherently high specific leaf area (SLA) tended to produce smaller rosettes than low-SLA families. These results are consistent with the view that a selective advantage may accrue from either high or low values of individual RGR components, depending on habitat conditions, and that the selective advantage of low trait values in nutrient-poor environments may results in indirect selection for low RGR in these habitats.  相似文献   

6.
为选育枫香(Liquidambar formosana)优良家系,对其24个种源310个家系的遗传变异进行分析,采用多目标决策法选育用材林优良家系及单株。结果表明,9年生枫香胸径、树高、材积、第一枝下高、冠幅和树干通直度等性状在种源和家系间存在显著差异(P0.01),以云南富宁、广西凭祥和江西湖城3个种源的材积生长表现最佳。各性状的家系遗传力属于中等遗传控制,为0.24~0.44,单株遗传力为0.20~0.50。共选出优良家系26个和单株41株,优良家系的平均胸径、树高、材积、冠幅、树干通直度分别大于总体均值的19.63%、18.56%、52.16%、5.11%和4.03%;遗传增益分别为6.67%、8.24%、20.28%、1.82%和1.75%,优良单株平均材积大于总体均值的150.25%。这为枫香育种策略制定和生产应用等提供理论依据。  相似文献   

7.
为选择短枝木麻黄(Casuarina equisetifolia)的优良家系,对来自10个国家23个种源109个家系的短枝木麻黄生长性状进行综合选择。结果表明,造林42个月后短枝木麻黄的树高、胸径、单株材积、抗虫性、健康状况和保存率在种源和家系间均存在极显著或显著差异。印度种源(18118)、中国种源(18267、18268和18586)、泰国种源(21199、18299和18297)在生长速度上表现较好;肯尼亚种源(18144、18142、18135)、澳大利亚种源(17862)、瓦努阿图种源(18312和18565)的抗虫性较好;瓦努阿图种源(18312)和肯尼亚种源(18142)的健康状况表现较好;中国种源(18586)、越南种源(18128)和肯尼亚种源(18144)的保存率较高。单株材积的遗传力最高,保存率和抗虫性的较低,健康状况的最低。利用单株材积、抗虫性、健康状况和保存率进行指数选择,按25%的入选率,28个综合性状优良的家系可作为下一步杂交育种的遗传材料。  相似文献   

8.
We sampled four wild populations of the highly autogamous Spergularia marina (Caryophyllaceae) in California to detect and to measure the magnitude of within- and among-population sources of phenotypic variation in gender and floral traits. From flowers and fruits collected from field and greenhouse-raised plants, we measured ovule number, seed number, mean seed mass, pollen production (greenhouse families only), mean pollen grain volume (greenhouse families only), anther number, anther/ovule ratio, pollen/ovule ratio (estimated using different flowers for pollen than for ovules; greenhouse families only), petal number, and petal size. Using greenhouse-raised genotypes, variation among maternal families nested within populations was evaluated for each trait to determine whether populations differ in the degree of maternally transmitted phenotypic variation. For each population, we used 15 greenhouse-raised maternal families to estimate the broad-sense heritability and genetic coefficient of variation of each floral trait. The magnitude and statistical significance of broad-sense heritability estimates were trait- and population-specific. Each population was characterized by a different combination of floral traits that expressed significant maternally transmitted (presumably genetic) variation under greenhouse conditions. Flowers representing two populations expressed low levels of maternally transmitted variation (three or fewer of nine measured traits exhibited significant maternal family effects on phenotype), while flowers representing the other two populations exhibited significant maternal family effects on phenotype for five or more traits. Our ability to detect statistically significant differences among the four populations depended upon the conditions under which plants were grown (field vs. greenhouse) and on the floral trait observed. Field-collected flowers exhibited significant differences among population means for all traits except anther number. Flowers sampled from greenhouse-raised maternal families differed among populations for all traits except ovule number, seed number, and petal size. We detected negligible evidence that genetic correlations constrain selection on floral traits in Spergularia marina.  相似文献   

9.
Most studies of sexual dimorphism in mammals focus on overall body size. However, relatively little is known about the differences in growth trajectories that produce dimorphism in organ and muscle size. We weighed six organs and four muscles in Rattus norvegicus to determine what heterochronic and allometric scaling differences exist between the sexes. This cross-sectional growth study included 113 males and 109 females with ages ranging from birth to 200 days of age. All muscle and organ weights were ultimately greater in males than in females, because males grew for a longer period of time, had a greater maximum rate of growth, and spent more time near the maximum rate. No ontogenetic scaling differences existed between the sexes in organ weight except for lungs and gonads. During growth, organ weights were negatively allometric to body weight. No scaling differences relative to body weight existed between the sexes for muscles; however, there was variation in the allometric relations among muscles relative to body weight. Sexual dimorphism in muscles and organs appears to be a size difference resulting from differences in the duration and rates of growth.  相似文献   

10.
为了研究电学参数与红砂(Reaumuria soongorica)抗旱性的关系,以4个地理种源的荒漠植物红砂2年生苗木为材料,测定其茎在不同干旱胁迫处理下的高频电阻(r)、低频电阻(rl)、胞外电阻率(re)、胞内电阻率(ri)、电导(G)和电纳(B)等电学参数以及膜透性(RPP)和渗透调节物质脯氨酸(Pro)含量的变化,分析电学参数与膜透性和脯氨酸含量间的相关性。结果显示,随着干旱胁迫的加剧,4个地理种源红砂茎的膜透性和脯氨酸含量均呈逐渐升高或先升高后降低趋势,不同种源间存在显著差异(P0.05)。红砂茎膜透性的大小在4个种源间表现为:兰州张掖酒泉武威,脯氨酸含量由高到低依次为武威酒泉张掖兰州。4个地理种源红砂茎的高频电阻呈逐渐下降趋势,胞外电阻率、胞内电阻率、电导呈先升高后降低的趋势,而低频电阻则与它们相反,电纳的变化则较为复杂。6个电阻参数在不同种源材料间和不同处理间差异均显著(P0.05)。相关性和通径分析结果表明,胞外电阻率、胞内电阻率、高频电阻和电纳与膜透性的相关性较为明显;胞外电阻率、胞内电阻率、高频电阻和电导与脯氨酸含量的相关性较为显著,其中胞内电阻率对膜透性和脯氨酸含量的影响最大,通径系数绝对值分别高达0.938和0.897。说明电学参数ri可以作为表征红砂抗旱特性的参数,也表明电学方法将是荒漠植物逆境胁迫研究的一种有效方法。  相似文献   

11.
Shoot water relations and morphological responses to drought preconditioning were studied by subjecting 5-month-old seedlings of three provenances of Eucalyptus globulus to different water regimes for 36 days in a greenhouse pot study. Moderately stressed plants were watered every 6 days and severely stressed plants were watered every 9 days. Control plants were watered daily. Drought cycles induced significant changes in morphological and physiological characteristics. Preconditioned seedlings were smaller in size, root collar diameter, height, and leaf area than control seedlings. Shoot/root ratio was not affected by drought. Osmotic potential at full turgor (ψπFT) and osmotic potential at turgor loss point (ψπTLP) were significantly lower and the magnitude of osmotic adjustment was significantly higher under the severe than under the moderate stress treatment. In severely stressed plants a decrease of turgid mass/dry mass contributed to osmotic adjustment. In a subsequent acclimation test, preconditioned seedlings showed higher values of stomatal conductance, predawn relative water content and water potential and lower mortality than control plants. These variables were significantly related to ψπFT. We assume that the reduced leaf area and osmotic adjustment observed in preconditioned seedlings contributed to drought acclimation in the selected E. globulus provenances leading to better rates of gas exchange and improved water status than non-conditioned plants. Provenances exhibited differences in their responses to drought, albeit mainly morphological differences. E. globulus subsp. bicostata from Tumbarumba grew more quickly (larger diameter and height relative growth rate) than the other provenances, implying a greater ability to tolerate water stress. It can be expected that preconditioned seedlings will display greater tolerance of water stress than non-conditioned plants and perform better during early establishment (higher survival and early growth).  相似文献   

12.
低磷胁迫下不同种源马尾松的根构型与磷效率   总被引:5,自引:0,他引:5  
以浙江淳安、福建武平、广西岑溪和广东信宜4个代表性的马尾松种源为试材,设置异质低磷胁迫、同质低磷胁迫等不同磷素处理,研究马尾松种源感知不同类型低磷胁迫的根构型及磷效率变异规律.结果表明:无论在异质低磷还是同质低磷胁迫下,参试种源马尾松的主要生长性状和磷效率指标均存在极显著的种源间变异.异质低磷胁迫下,广东信宜、福建武平种源马尾松表现出较高的磷效率和干物质积累量,根构型发生适应性变化,富磷表层介质中的根系参数显著高于低磷效率的广西岑溪和浙江淳安种源.这是磷高效种源具有较高的磷素吸收效率和磷效率的重要机制.不同种源的表层富磷介质根系参数与其整株干物质积累量相关系数在0.95以上.同质低磷胁迫下,高磷效率种源马尾松的磷吸收率显著高于低磷效率种源,但表层介质中的根系参数和整株根系参数与整株干物质积累量的相关性较低.不同种源马尾松适应同质低磷胁迫和异质低磷胁迫的生物学机制有所差异,应有针对性地选择不同土壤磷素的森林立地并推广磷营养高效的马尾松种源.  相似文献   

13.
木荷稳定碳同位素分辨率的种源差异   总被引:1,自引:0,他引:1  
利用设置在福建建瓯、浙江淳安和浙江庆元3个区试点的5年生木荷种源试验林,选取18个代表性种源测定叶片的稳定碳同位素分辨率(Δ值),研究其在种源间的差异和地理变异模式,以及造林立地环境和种源生长对其的影响.结果表明:木荷种源叶片稳定碳同位素分辨率存在很大差异,福建建瓯、浙江淳安和庆元3个区试点的叶片Δ值最高和最低种源分别相差6.9%、3.0%和3.7%.种源叶片Δ值与其产地纬度呈显著负相关,而与产地经度的相关性较小,表现为典型的纬向渐变模式,来自木荷分布区南部的种源叶片Δ值较大,说明其长期水分利用效率较低.随着造林立地环境的改善和年降雨量的增多,木荷叶片Δ值显著增加.种源叶片Δ值与其树高、胸径、一级侧枝总数和最大侧枝长等皆呈显著正相关,树冠浓密的速生种源具有较高的Δ值.此外, 在木荷中心产区(福建建瓯)和边缘产区(浙江淳安)分别初选出2个和4个水分利用效率高的速生优良种源,供推广应用.  相似文献   

14.
以3个来源于广东茂名的土沉香[ Aquilaria sinensis (Lour.) Spreng.]种源(大白、小白和大黄)和1个来源于云南的土沉香种源的1年生幼苗为研究对象,对不同遮光条件下[相对光强100%(对照,自然光强)、50%、25%和5%]4个种源幼苗叶片的净光合速率(Pn)的光响应和CO2响应曲线、光合和气体交换参数、叶绿素含量和叶绿素a/b( Chla/b)值进行了分析,并比较了4个种源幼苗的相对生长速率(RGR).结果表明:4个种源的Pn均随光合光量子通量密度的增加而上升,且对照组各种源的Pn值均明显高于各处理组;4个种源的Pn值均随胞间CO2浓度的升高或相对光强的增大逐渐提高.随相对光强的降低,4个种源的最大光合速率、光补偿点、光饱和点、暗呼吸速率、最大电子传递速率、最大羧化速率和磷酸丙糖利用速率均下降或显著下降(P<0.05),而表观量子效率则略有升高.在相对光强100% ~ 25%条件下,随相对光强降低,4个种源的叶绿素含量显著提高、Chla/b值显著减小;大白和小白种源的RGR逐渐增大,大黄种源的RGR差异不显著,而云南种源的RGR显著减小.而在相对光强5%条件下,大黄和云南种源的叶绿素含量显著降低,Chla/b值显著增大,RGR显著减小;大白和小白种源幼苗全部死亡.由种源间的比较可见:4个种源的各项光合参数以及叶绿素含量、相对生长速率均有一定的差异,其中云南种源的各项指标总体上均最低.综合来看,土沉香为半阳生植物,对不同的光环境表现出相对较强的适应性.  相似文献   

15.
Foliar plasticity in response to ontogeny, location within the plant and environmental changes is widespread among long-lived organisms. To quantify the phenotypic variation in needle morphology and anatomy in response to a climate gradient, we compared contrasted populations of Pinus canariensis grown in five sites inside and outside the natural distribution area of the species. Most needle and growth traits were strongly affected by site. In general, site xericity increased the relative area of the dermal and transfusion tissues and decreased mesophyll and endodermis. Within each site, provenances from less productive locations tended to show longer needles, less relative area of dermal tissues but higher relative area of mesophyll and transfusion tissue than provenances from fertile origins. Although sclerophylly increased with aridity, no genetic differences were found for this trait thus apparently the ontogenetic delay of some provenances in xeric environments was not related with the formation of tougher needles. Several patterns of phenotypic response to different environments were shown. In general, all traits were plastic but the degree of plasticity was higher in traits related with growth than foliar traits. These results, combined with formerly published research, suggest that highly plastic populations rather than narrowly specialized ones have been selected in this species to cope with the complex interaction of environmental factors in its habitat.  相似文献   

16.
Investment in reproduction and growth represent a classic tradeoff with implication for life history evolution. The local environment can play a major role in the magnitude and evolutionary consequences of such a tradeoff. Here, we examined the investment in reproductive and vegetative tissue in 40 maternal half‐sib families from four different populations of the herb Plantago coronopus growing in either a dry or wet greenhouse environment. Plants originated from populations with an annual or a perennial life form, with annuals prevailing in drier habitats with greater seasonal variation in both temperature and precipitation. We found that water availability affected the expression of the tradeoff (both phenotypic and genetic) between reproduction and growth, being most accentuated under dry condition. However, populations responded very differently to water treatments. Plants from annual populations showed a similar response to drought condition with little variation among maternal families, suggesting a history of selection favouring genotypes with high allocation to reproduction when water availability is low. Plants from annual populations also expressed the highest level of plasticity. For the perennial populations, one showed a large variation among maternal families in resource allocation and expressed significant negative genetic correlations between reproductive and vegetative biomass under drought. The other perennial population showed less variation in response to treatment and had trait values similar to those of the annuals, although it was significantly less plastic. We stress the importance of considering intraspecific variation in response to environmental change such as drought, as conspecific plants exhibited very different abilities and strategies to respond to high versus low water availability even among geographically close populations.  相似文献   

17.
This study presents an evaluation of an irrigated “market garden” trial established with 3-month-old seedlings of baobab. The trial included offspring from 59 open-pollinated family lots from ten provenances and four bulked provenance sample lots. Leaf productivity and seedling growth were evaluated monthly from the third month after establishment. We found lowered leaf productivity during the dry season despite the plants being irrigated. We provide the first estimates of heritability for leaf production and growth of the species. We assumed that the families of seed from open-pollinated single trees consist of true half-sibs but also provided adjusted estimates assuming a high level of selfing. Differences among provenances and families within provenances were highly significant (p?<?0.01) with respect to leaf productivity. Heritability estimates (adjusted and non-adjusted) for leaf productivity were moderate to low, predicting moderate genetic gain from selection. Strong genetic and phenotypic correlations were estimated between diameter and leaf production, indicating that simple selection for diameter can efficiently increase leaf production. The dry weight/fresh weight ratio was not significantly different among provenances or families within provenances. Based on the findings, we discuss how breeding can increase the total leaf production and its seasonal distribution.  相似文献   

18.
米老排种源家系生长性状变异分析及早期选择   总被引:1,自引:0,他引:1  
为分析米老排生长性状在种源和家系间的变异规律,筛选出速生的米老排优良种源和家系。以来自8个米老排地理种源的116个家系为研究对象,对米老排生长性状进行种源间和家系间遗传变异分析和育种值综合评分。结果表明:不同米老排种源间和家系间生长性状的差异均达到极显著水平。生长量最高的GXPX种源的平均树高、胸径和单株材积分别为9.50 m、13.40 cm、0.079 9 m3,是最差种源GXFC的1.28、1.42和2.30倍;生长最快家系是PX01,其平均树高、胸径和单株材积分别为9.86 m、15.31 cm和0.101 6 m3,其株材积是最差家系FC01的4.01倍,是家系群体均值的1.94倍。通过单性状选择对种源进行选择,初步选出2个优良种源,其树高、胸径和单株材积的预期遗传增益分别达到8.87%、11.79%和34.70%;运用育种值综合评分法对家系进行选择,初步选出12个优良家系,其树高、胸径树高和材积的预期遗传增益分别达到11.57%、17.35%和52.06%。GXPX和GXLZ 2个种源,PX01、LZ03、PX02、DB08、PX10、PX04、PX09、DB07、DB16、LZ05、JX16和PX05等12个家系是选出的综合生长表现最好的优良种源和家系,可作为米老排良种材料进行申报并推广。  相似文献   

19.
 Measurements of morphological and anatomical characteristics made on 4-month-old seedlings from five provenances of Parkia biglobosa (Jacq.) Benth., grown in a tropical greenhouse under controlled conditions, showed significant differences between the northern provenances, which represented the Sudan savanna zone, and the southern provenances which represented the forest zone of the species distribution. Seedlings of provenances from the savanna zone showed more xerophytic characteristics than those from the forest zone. They were smaller in height, with a greater number of smaller leaflets per pinnae, a lower specific leaflet mass, smaller palisade and guard cells and a lower ratio of palisade:non-palisade tissue. There were also significant differences in the same characteristics, except palisade cell length, between provenances from the easterly and westerly extremes of the species range. Stomatal conductance measured after 2 weeks of droughting also showed that provenances from the savanna zone had higher values, indicating greater physiological activity and reduced stress, compared with provenances from the forest zone. Multivariate discriminant analysis of the morphological and anatomical characteristics showed that 98% of the seedlings were classified correctly with respect to provenance. The squared distances between provenances were closely related to the geographical distances between locations. Yet, not all variation in leaf anatomy could be explained by the difference in climatic conditions from north to south. Also drought tolerance was not always related to morphological and anatomical features. It is possible that clinal variation within the species from east to west may be interacting with climatic differences from north to south. Received: 2 June 1998 / Accepted: 29 June 1998  相似文献   

20.
Inter-populational differentiation and adaptation in California Fragaria vesca L. were examined using plants collected from 13 natural sites, grown in a common greenhouse and analyzed for 25 quantitative traits and 2 enzyme systems. Inter-populational variation was estimated by analysis of variance and genetic identity techniques, and micro- and macro-environmental measurements were made at each site. Stepwise multiple regressions were completed on the morphological-environmental variations and the allozyme frequency-environmental variations. Clonal propagules were compared under three controlled environmental conditions. F. vesca likely has undergone considerable ecological differentiation since significant inter-populational variation was observed in many polygenic and monogenic traits. Numerous significant correlations between environmental and character variations were found, and in many, only a few environmental variables “explained” much of that variation. Inter-populational differences in the abilities of plants to accumulate biomass and survive under salt, nutrient and shade stresses were also found. Although many of the ecotypes of F. vesca showed some phenotypic plasticity, the species is a “specialist.” Variations in root/shoot ratios occurred in biotypes grown under different conditions. Plants generally allocated more energy to aboveground biomass under shade stress and to root biomass under nutrient stress.  相似文献   

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