Abscisic acid relationships in the chill-related dormancy mechanism in apple seeds

Abscisic acid (ABA) levels in seeds from three cultivars of apple (Malus domestica Borkh.) which have substantially different chilling requirements were investigated by gas chromatography mass-spectrometry selected ion monitoring (GCMS-SIM) during stratification. The ABA content of dormant unchilled seeds was similar in the three cultivars, suggesting no relationship between the chilling requirement of those seeds and their ABA status. That chilling is not related to ABA changes during stratification was confirmed by warm (20°C) and cold (5°C) stratification experiments. ABA content dropped rapidly and nearly identically under both temperature regimes, but only cold stratification promoted germination. The decline in ABA during stratification was due in large part to leaching from the seed coat and nucellar membrane; the ABA content of the embryo remained nearly constant. The radicle in intact seeds stratified at 5°C began growing 20–30 days after the ABA in the seed coat and nucellar membrane had nearly disappeared. Radicle growth did not occur in unchilled seeds, even though ABA had leached from them as well. It is possible that the leaching of ABA from the seed allows certain promotive forces to develop, but if so, these can develop only at chilling temperatures. Studies were also conducted on 2-trans ABA relationships to apple seed dormancy, but no association was evident.Report No. 12, Department of Fruit and Vegetable Science, Cornell University.     

The nature of the interference potential ofPluchea lanceolata (DC) C B Clarke (Asteraceae)

The causes of the interference success of the weedPluchea lanceolata were studied. It was found that the weed achieves its success by inhibiting seed germination and seedling growth of different plant species through water-soluble phytochemical compounds synthesized by the weed and released by it in the soil.     

Calcium and temperature effects on seedling exudation and root rot infection of common bean on an acid sandy soil

Soil born fungi such as Phytium ultimum, Fusarium ssp., and Rhizoctonia solani (Kühn) severely restrict stand establishment of common bean (Phaseolus vulgaris L.) on acid soils of the Tropics. Calcium application is known to alleviate fungal infection in many legumes but the causes are still unclear. To investigate environmental factors and physiological mechanisms involved, growth chamber experiments were conducted with an acid sandy soil from Mexico. Treatments were soil liming at a rate of 0.67 g Ca(OH)₂ kg^-1, gypsum application at 0.49 g CaSO₄ 2H₂O kg^-1 soil placed around the seed, and an untreated control. Beans were grown under three temperature regimes with constant night and one constant day vs. two sinusoidal day temperatures. To examine patterns of seed and seedling exudation at regular intervals leachates of germinating seeds were collected on filter paper soaked with equilibrium solutions from soils of the three treatments. The severity of root rot in the control treatment was highest when plants were stressed by temperature extremes. At a sinusoidal day temperature peaking at 40°C soil liming and gypsum application to the seed increased the number of healthy seedlings similarly by over 60%. However, only liming which effectively eliminated growth constraints by low pH and high aluminum concentrations led to an increase in hypocotyl elongation by 22% and in total root length by 8%. Both calcium amendments increased the calcium and potassium contents in the hypocotyl tissue. From seeds exposed to the equilibrium solution of unlimed soil with pH 3.7, 1 mM Ca, and 0.6 mM Al considerable amounts of amino acids and carbohydrates were leached. In contrast, exposure to the equilibrium solution from limed soil with pH 4.3, 3 mM Ca, and negligible concentrations of Al led to a net uptake of amino acids and decreased leaching of carbohydrates. Exposure to the equilibrium solution of the gypsum treatment with pH 3.6, 20 mM Ca, and 1.2 mM Al resulted in a somewhat smaller net uptake of amino acids compared to liming. During germination pH around the seeds steeply increased in the untreated control but significantly less with both amendments. The results indicate that pH and the Ca/Al ratio in the soil solution around bean seeds determine their pattern of exudation and solute uptake. For bean germination and early growth on acid soils locally placed application of small amounts of gypsum as seed pelleting seems as effective as soil liming in reducing the incidence of root rot. The results indicate that this may be accomplished by decreasing the amount of leachates available for fungal development.     

Interspecific pollen transfer as a mechanism of competition: Consequences of foreign pollen contamination for seed set in the alpine wildflower,Polemonium viscosum

Summary Earlier studies showed that under natural conditions foreign pollen receipt is correlated with loss of seed set in populations of P. viscosum. Here, we report on experimental pollinations using foreign pollen from two co-flowering species that share pollinators with P. viscosum. Experiments were designed to ascertain whether improper pollen transfer causes reduced seed set under controlled conditions and, if so, to determine the stage at which interference occurs. In flowers pre-treated by pollination with either Mertensia or Castilleja pollen, adherence of subsequently deposited conspecific pollen grains was unaffected. However, conspecific grains had significantly lower germination and ovule fertilization success in flowers receiving foreign pollen than in controls. These results suggest that pollinator infidelity in high alpine plant communities can reduce female reproductive success of P. viscosum by inhibiting the performance of conspecific pollen grains. Negative effects of Mertensia and Castilleja pollen were comparable despite large interspecific differences in pollen grain morphology. Accordingly, susceptibility to foreign pollen interference appears to be an intrinsic property of P. viscosum that is not dependent on the unique structural properties of pollen produced by competitive species.     

种子散布位置对格氏栲幼苗根系形态及生长特征的影响

种子从母株掉落于地面萌发后,其根系在不同散布位置(凋落物上层、土壤表层和凋落物下层)的生长形态影响幼苗定居及建成,而目前对其根系形态及生长特征的了解并不充分,限制了对幼苗根系在不同散布下适应策略的理解。为此,以格氏栲(Castanopsis kawakamii)为研究对象,通过模拟种子在凋落物中位置,设置凋落物上层(种子下层铺垫2 cm和4 cm凋落物,U2和U4处理)、土壤表层与凋落物下层(种子上层覆盖0、2、4、6 cm和8 cm凋落物,CK、D2、D4、D6和D8处理)等3种散布,探讨不同散布位置对格氏栲幼苗根系9个生长指标的影响。结果表明：(1)种子散布位置对幼苗根干物质质量具有显著影响,D2处理达最大值。(2)D2处理的幼苗根长、根表面积、根尖数、分枝数和比根长高于其它处理;根系平均直径在D6处理达最大值。(3)相关分析表明根长、根表面积、根尖数、分枝数和比根长与根系平均直径呈显著负相关关系。(4)对根系9个生长指标提取主成分后聚类为4个类群,D2与D4处理各划分一类;U2与U4处理划分一类,其余三个处理划分一类。综上所述,凋落物浅层覆盖(D2处理)适宜格氏栲根系生长;凋落物...     

Barley hordothionin accumulates in transgenic oat seeds and purified protein retains anti-fungal properties in vitro

Summary Transgenic anti-fungal gene expression in heterologous species provides a means to test resistance protein combinations across species barriers. This is the first report of transgenic anti-fungal seed storage protein accumulation in oat seed. An anti-fungal barley (Hordeum vulgare L.) hordothionin (Hthl) gene was genetically engineered into oat (Avena sativa L.) to determine the effect of hordothionin on pathogen resistance. The transgene was expressed in both leaf and seed tissue, with transgenic protein accumulation occurring only in the seed. Transgenic oat line HTH-Av5 expressed c. 94 μg HTH/g seed, 19% of native barley seed levels. The anti-fungal activities of HTH fractions from barley cv. Morex and oat (transgenic and control) were tested in an in vitro growth assay against an important small grain pathogen. Fusarium graminearum. The partially purified HTH fractions from control oat seeds did not inhibit fungal growth, while HPLC-purified HTH positive control, as well as partially purified barley and transgenic oat HTH inhibited growth similarly over a range of concentrations. These results indicate hordothionin can be expressed in a heterologous cereal species and still maintain its anti-fungal properties. Future studies with HTH targeted to additional tissues are planned to test for increased fungal resistance. The University of Wisconsin and the USDA neither guarantee nor warrant the standard of the products named herein, and the use of the name by University of Wisconsin or USDA implies no approval of the product to the exclusion of others that may also be suitable.     

Tailoring Tropane Alkaloid Accumulation in Transgenic Hairy Roots of Atropa baetica by Over-expressing the Gene Encoding Hyoscyamine 6β-hydroxylase

Atropa baetica hairy roots, over-expressing cDNA from Hyoscyamus niger encoding the gene for hyoscyamine 6β-hydroxylase (H6H), were produced by Agrobacterium rhizogenes infection. The transgenic roots over-expressing h6h had an altered alkaloid profile in which hyoscyamine was entirely converted into scopolamine. In the best h6h clone, scopolamine accumulation increased 9-fold compared to plants, amounting to 5.6 mg g dry wt⁻¹, some of which was released into the liquid medium. Only negligible amounts of hyoscyamine were detected. In contrast, the gus control culture contained a much higher amount of hyoscyamine than scopolamine, mimicking the situation in the plant. At the molecular level, a higher conversion of hyoscyamine into scopolamine was related to a higher level of h6h mRNA; in some instances this was 5–10-fold higherThis article is dedicated to the memory of Professor Antonio G. González     

Fungicide seed treatments increase growth of perennial ryegrass

Field, laboratory and glasshouse experiments were carried out to measure effects of seed treatments with captan or thiram on growth of perennial ryegrass (Lolium perenne L.). Field-sown captan- or thiram-treated seed gave twice as many seedlings as untreated seed. Spaced plants growing from fungicide-treated seed produced almost 6 times more dry matter 16 weeks after sowing than those from untreated seed. This effect, though diminishing with time, was still apparent more than a year after sowing. Fungicides in sterile agar growth medium were phytotoxic to seedlings at concentrations of 10μg/ml and greater. Seedlings grown from treated seeds sown from 5 to 15 mm away from developing colonies of the virulent seedling pathogenFusarium oxysporum Schlecht. were more than 4 times larger than those grown from untreated seeds. Captan-treated seed sown into pots containing field soil produced more and larger seedlings than untreated seed. Methyl bromide fumigation of the same soil also increased both number and size of seedlings. Fungicidal, rather than direct chemical effects, at early stages of seedling growth, account for increased growth of plants from fungicide-treated seed.     

Effects of seed phosphorus concentration on the emergence and growth of subterranean clover (Trifolium subterraneum)

Subterranean clover seed (Trifolium subterraneum cv. Dalkeith) with phosphorus concentrations of 0.75% (high P seed) and 0.48% (low P seed) and of uniform size (2.0–2.4 mm diameter) was used to measure the effect of seed P concentrations on seedling emergence and growth.Seedling emergence numbers were 35% greater for the high P seed, and this effect was independent of external P supply. High P seed also emerged more quickly than low P seed.Leaf emergence was faster and shoot dry weight was greater for seedlings grown from high compared with low P seed, but only when external P supply was deficient for plant growth. Phosphorus concentrations in the shoots of two-week old seedlings were 32–51% higher for high P seed, although by four weeks plants grown from high and low P seed had similar concentrations of P in their shoots. We suggest that establishing pastures using high P seed would improve both early and late season pasture production.     

Spatiotemporal variation in predispersal seed predation intensity

The effect of predispersal seed predation by Bruchus atomarius (Bruchidae, Coleoptera) on individual performance and population dynamics of the perennial forest herb, Lathyrus vernus (Leguminosae), was investigated in 11 permanent plots over 4 years. Seed predation and parameters describing intra-specific neighbour distance, plant size, inflorescence size, flowering phenology and current and previous herbivore damage were measured on all plants. In addition, demographic information from all plots was analysed using transition matrix population models in order to estimate the influence of seed predation on population growth rates. Predispersal seed predation rates differed significantly among years. Plot averages ranged from 0 to 83.7%. However, most of the variation occurred among individuals. Within individuals there was no consistency in predation rates among years. Exposure to herbivory, plant size and flowering phenology did not affect predation rates but individuals with larger inflorescences suffered from significantly higher predation. Seed predation in L. vernus was not influenced by neighbour distances of individual plants but it was positively correlated with the average density of seeds within plots, suggesting that seed predation is density dependent at the patch level. The reduction in population growth rate due to seed predation ranged from 0 to 7.6%. The sensitivity of population growth rate to reductions in seed production varied considerably among years and plots. This variation was mainly due to differences in the reproductive value of seeds and seedlings. The intensity of seed predation over the range found was not correlated with changes in population growth rate. The results of this study suggest that the influence of external factors, like seed predation, on population growth rate largely depends on the demographic transition rates in the investigated population.     

不同产地降香黄檀种子和幼苗性状的变异研究

为了探讨不同产地降香黄檀(Dalbergia odorifera)种子和幼苗的表型性状变异规律,该研究以来源于海南、福建、广西、广东等省/区10个产地降香黄檀的种子及在广西桂林培育的幼苗为材料,采用方差分析、相关性分析和主成分分析对其种子和幼苗生长的9个表型性状进行了比较研究。结果表明:降香黄檀种子和幼苗的表型性状存在较大变异,9个性状间均差异极显著,各性状平均变异系数(CV)为12.50%,变异系数范围在7.94%～18.89%,幼苗生长性状的变异高于种子性状的变异,说明种子性状的稳定性较高。相关分析表明各表型性状间及表型性状与地理-气候因子间均存在不同的相关性,各表型性状与经度、纬度及年降水量均无显著相关性,而海拔、年均温度与年降雨量是影响降香黄檀种子和幼苗性状的主要因子。利用主成分综合得分法,筛选出了3个在种子形态、幼苗生长和萌发情况等方面较好的家系,按综合得分排序分别为仙游产地、儋州产地、尖峰岭产地。研究结果可为降香黄檀优良种质资源的筛选提供科学依据。     

掌叶木种皮障碍及种子各部位内源抑制活性的研究

掌叶木(Handeliodendron bodinieri)是残遗于中国的稀有单种属植物,因人为破坏、生境特殊及自身特性的影响,资源稀少,被列为国家一级重点保护野生珍稀濒危植物。该研究以掌叶木种子为材料,研究了4种不同发芽条件下(带种皮、浓硫酸处理种皮、完全去除种皮、仅露出胚根)种子萌发性、种皮透水性、掌叶木果皮、假种皮、种皮和种仁四个部位不同浓度甲醇浸提物(0、3.125、6.25、12.5、25 mg/m L)对白菜种子萌发及幼苗生长的影响以及掌叶木各部位浸提物对种子萌发的影响。结果表明:(1)掌叶木种皮具有一定的透水性,为掌叶木种子的萌发提供必要的透水透气条件,不影响种子萌发前的水分吸收,但掌叶木种皮的机械阻碍、易霉变对种子的萌发影响较大。(2)掌叶木的果皮、假种皮、种皮和种仁甲醇浸提物对白菜种子的萌发和生长都有影响,尤其对白菜幼根的生长有较强的抑制作用,抑制强度依次是种仁果皮假种皮种皮,且随着浓度的升高,抑制作用增强。该研究结果揭示了掌叶木种子难发芽、发芽率低的原因,为掌叶木的人工扩繁和保护与利用奠定了基础。     

Does pre-dispersal seed predation limit reproduction and population growth in the alpine clonal plant Geum reptans?

We studied the impact of the seed damaging gall midge larva Geomyia alpina on its perennial alpine host plant Geum reptans. We analysed the effect of seed predation on reproduction by seeds, i.e. seed number, seed mass, and seed viability and on growth and clonal propagation of non-protected plants in comparison to plants protected from predation by an insecticide. Additionally, we assessed the consequences of seed predation for population growth using matrix projection modelling. Seed predation resulted in a decrease in total seed mass per flower head by 23.8% in non-protected plants (P < 0.05). Individual seed mass decreased with increasing infestation intensity (P < 0.05). Seed number remained unaffected because the sucking feeding behaviour by gall midge larvae does not evoke seed abortion. Percent germination of seeds from non-protected plants was reduced by 97.9% compared to seeds from protected plants. According to reduced seed viability, modelling revealed a decrease in population growth rate from λ = 1.055 to λ = 1.041. Predation did neither influence total plant biomass nor biomass fractions. But stolon dry-weight of non-protected plants increased by 24.1% (P < 0.05), which may indicate a trade-off between sexual reproduction and clonal propagation. Our results demonstrate that despite substantial reduction of viable seeds, predation by gall midge larvae only slightly affected population growth of G. reptans suggesting that in this alpine species, persistence by longevity and clonal propagation can balance potential seed losses by predation, at least for local population growth.     

巨尾桉叶片挥发物对三种植物种子萌发及幼苗生长的化感效应

为探讨人工巨尾桉林叶片挥发物对周边农作物的化感作用,采用不同质量新鲜巨尾桉叶片及由新鲜叶片提取的桉叶油对玉米、辣椒、西红柿等三种植物种子进行处理,观测其种子萌发和幼苗生长状况。结果表明:(1)在三种被测植物中,桉树叶片挥发物对玉米种子萌发影响最小,对辣椒影响最大;(2)当叶片用量小于200g时,桉树叶片挥发物对三种植物种子萌发影响不明显,当叶片用量达400g时,能完全抑制辣椒、西红柿种子萌发,并能极显著降低玉米种子萌发(P0.01);(3)玉米幼苗芽生长随叶片用量的增加呈现先促进后抑制现象,对芽高、鲜重、干重的促进和抑制均达到显著(P0.05)或极显著水平(P0.01);(4)当叶片用量小于或等于100g时,桉树叶片挥发物对辣椒、西红柿幼苗生长影响不明显,当用量达到200g时则能极显著抑制辣椒、西红柿幼苗生长;(5)桉叶油对三种测试植物的抑制效果与叶片自然挥发物相似,且效果更显著。     

不同产地苦楝苗期生长节律研究

苦楝在我国分布广泛,具有丰富的遗传变异性。为进一步做好苦楝种源筛选和良种选育工作,该文对不同产地苦楝实生苗生长性状和各阶段的生长特点进行了比较分析,初步揭示了苦楝苗期生长规律。以15个产地的1年生实生苗为试材,对苗高、地径、复叶生长及生物量积累等生长性状进行了观测分析,并用Logistics方程对生长节律进行了拟合。结果表明:(1)不同产地苦楝苗高、地径生长差异均达显著水平,根生物量、茎生物量及复叶相关性状差异均达极显著性水平;(2)苗高和地径生长均呈现慢-快-慢的S型生长规律,且均存在2次生长高峰,与苗高生长高峰出现时间相比,地径生长高峰出现时间较晚;(3)Logistic拟合方程的R²为0.976～0.994,均达到极显著相关水平,说明可用Logistic方程拟合苦楝的生长节律;(4)总体上地径速生期较苗高速生期长20～30 d,北方产地苗高和地径进入速生期和结束速生期的时间均早于南方产地,速生期苗高和地径累积生长量均超过总生长量的60%;(5)各生长指标均与纬度负相关,苗高、生物量及复叶面积与经度正相关,其他指标与经度负相关。综上结果表明,苦楝为全期生长型树种,各生长性状在产地间达显著差异水平,生长受纬度和经度双重控制,以纬度控制为主。     

<Emphasis Type="Italic">Piriformospora indica</Emphasis> and <Emphasis Type="Italic">Sebacina vermifera</Emphasis> increase growth performance at the expense of herbivore resistance in <Emphasis Type="Italic">Nicotiana attenuata</Emphasis>

A Sebacinales species was recovered from a clone library made from a pooled rhizosphere sample of Nicotiana attenuata plants from 14 native populations. Axenic cultures of the related species, Piriformospora indica and Sebacina vermifera, were used to examine their effects on plant performance. Inoculation of N. attenuata seeds with either fungus species stimulated seed germination and increased growth and stalk elongation. S. vermifera inoculated plants flowered earlier, produced more flowers and matured more seed capsules than did non-inoculated plants. Jasmonate treatment during rosette-stage growth, which slows growth and elicits herbivore resistance traits, erased differences in vegetative, but not reproductive performance resulting from S. vermifera inoculation. Total nitrogen and phosphorous contents did not differ between inoculated and control plants, suggesting that the performance benefits of fungal inoculation did not result from improvements in nutritional status. Since the expression of trypsin proteinase inhibitors (TPI), defensive proteins which confer resistance to attack from Manduca sexta larvae, incur significant growth and fitness costs for the plant, we examined the effect of S. vermifera inoculation on herbivore resistance and TPI activity. After 10 days of feeding on S. vermifera-inoculated plants, larval mass was 46% higher and TPI activity was 48% lower than that on non-inoculated plants. These results suggest that Sebacina spp. may interfere with defense signaling and allow plants to increase growth rates at the expense of herbivore resistance mediated by TPIs.     

黄土丘陵区退耕还草植被恢复阶段优势种铁杆蒿的化感效应

为揭示黄土丘陵区退耕还草植被恢复阶段植被群落结构的形成与植物化感作用之间的关系,阐明退耕还草植被恢复阶段铁杆蒿群落形成的原因,采用种子萌发实验,对黄土丘陵区退耕还草中后期群落优势种铁杆蒿(恢复10 a、15 a、20 a、30 a)浸提液(水浸提液和甲醇浸提液)对其伴生种达乌里胡枝子(Lespedeza davurica,LD)、狗尾草(Setaria viridis,SV)、茵陈蒿(Artemisia capillaries,AC)以及铁杆蒿(Artemisia sacrorum,AS)自身化感作用进行研究。结果表明:铁杆蒿浸提液对3种伴生种以及自身种子萌发的化感作用差异显著(P0.05),总体表现出低促高抑"浓度效应",且根受到的抑制作用要强于芽。茎叶浸提液的浓度为0.1 g/mL时,对茵陈蒿种子萌发和幼苗生长的化感指数RI为-1.00,达到完全抑制。铁杆蒿不同器官的化感作用差异显著(P0.05),茎叶及根系浸提液不同程度的抑制LD、AC种子的萌发和幼苗生长,且在同一浓度下抑制作用随着恢复时间的增长逐渐增强。根际土浸提液促进了伴生植物及铁杆蒿自身种子的萌发,抑制了LD和AC幼苗的生长。铁杆蒿种群的化感作用可能是导致铁杆蒿在退耕还草中后期成为优势种的原因之一。     

Interference effects of Cassia uniflora Mill on Parthenium hysterophorus L.

In some parts of Karnataka and Maharashtra states (India), a leguminous undershrub, Cassia uniflora has effectively replaced the problematic weed Parthenium hysterophorus (parthenium). The studies revealed that the phenolic leachates from different parts of C. uniflora, specially from germinating seeds significantly inhibited the germination of parthenium seeds and retarded the growth of seedlings from the successfully germinated parthenium seeds. At field level, seedlings of C. uniflora outcompeted the seedlings of summer generation of parthenium causing reduction in height, dry weight and number of inflorescences of the latter which ultimately resulted in reduction of their seed output. Because of its longer life span, C. uniflora effectively prevented the establishment of parthenium plants of the winter generation in its area of growth. Results indicate that C. uniflora replaces parthenium through interference.     

无患子果实生长发育及其内含物的变化特征北大核心CSCD

以福建建宁县无患子为材料,观测果实生长动态,并采用Logistic方程对生长指标进行曲线拟合,观察生长过程中果皮显微结构变化,确定无患子果实生长发育的重要时期,为无患子的高效栽培管理和果实采收策略的制定提供科学依据。结果表明:(1)无患子果实生长、果皮总皂苷和种子油脂的积累规律相似,总体上呈Logistic增长模型的单“S”型曲线;果皮总皂苷和种子油脂的主要积累时期分别为45~90 DAP(花授粉后天数)和75~105 DAP。(2)无患子果皮除含有角质层、表皮细胞、厚角细胞、薄壁细胞、维管束、石细胞等基本结构外,还含有溶生式分泌腔和草酸钙簇晶等特征性结构;随着果实生长,分泌腔体积逐渐变大。(3)根据果实生长变化规律和Logistic方程拟合结果,可将无患子果实生长发育进程划分为生长初期(0~30 DAP)、速生期(30~90 DAP)、生长后期(90~120 DAP)和果实成熟期(120~150 DAP)4个阶段。在生产实践中果实成熟期内均适合果实采收,其中135和150 DAP分别为果实皂用和油用采收的最佳时期,此外还应根据每年天气状况对果实采收时间进行适当调整。     

盐磷胁迫对木麻黄和台湾相思种子萌发及幼苗生长的影响

恶劣环境下,人工海防林因面临养分胁迫而经营困难。为探讨盐、磷胁迫对主要海防林树种木麻黄和台湾相思种子萌发及生长的影响,该研究分别用不同浓度的NaCl(盐)和KH₂PO₄(磷)溶液处理种子和浇灌幼苗,测定种子萌发和幼苗生长指标。结果表明：(1)高盐胁迫显著抑制种子萌发,对幼苗生长有一定影响,但两种植物影响程度不同;台湾相思种子萌发耐盐性高于木麻黄,前者相对盐害率最大值为23.03%,后者为89.15%;随着盐浓度增加,木麻黄和台湾相思种子的发芽率、发芽势、发芽指数和活力指数均降低,对应最大值分别为38.70%、34.67%、18.70、0.055和76.67%、62.22%、48.46、6.11。(2)两种植物的株高和根长随盐浓度增加而降低,木麻黄和台湾相思株高分别为12.29～6.01 mm和48.27～17.33 mm,根长分别为8.57～1.45 mm和33.41～5.88 mm;台湾相思根、茎、叶生物量及根冠比均随盐浓度的增加逐渐减小,木麻黄各处理差异较小。(3)台湾相思的种子和幼苗较木麻黄更耐低磷环境,二者最适磷浓度存在差异;木麻黄种...