The lectin gene TRpL1 of tetraploid Robinia pseudoacacia L.response to salt stress

Lectins are natural proteins in animals,plants,and microorganisms and can be divided into 12 families.These lectins play important roles in various environmental stresses.Some polyploid plants show tolerance to environmental stresses and to insect pests.However,the mechanism of stress tolerance is unclear.Tetraploid Robinia pseudoacacia(4×)under salt stress showed higher tolerance than diploid R.pseudoacacia(2×).As lectin can improve stress tolerance,it was questioned whether the stress resistance of polyploid plants was related to the lectin protein.In this study,salt resistance of lectin gene TRpL1 was verified by its over-expression in plants.In addition,salt resistance of lectin protein by E.coli strains was detected.The data revealed that the over-expression transgenic plants of TRpL1 showed better salt tolerance than control plants under salt stress,and the TRpL1-expressing strain also grew better in the medium with added NaCl.Therefore,tetraploid plants can resist salt stress through TRpL1 protein regulation.

Leaf C:N:P stoichiometric homeostasis of a Robinia pseudoacacia plantation on the Loess Plateau

Homeostasis is the adaptability of a species to a changing environment.However,the ecological stoichiometric homeostasis of Robinia pseudoacacia L.in diff erent climatic regions is poorly understood but could provide insights into its adaptability in the loess hilly region.This study sampled 20 year-old R.pseudoacacia plantations at 10 sites along a north–south transect on the Loess Plateau.Variations in the ecological stoichiometric characteristics of leaf and soil carbon,nitrogen,and phosphorus were analysed and homeostatic characteristics of leaf ecological stoichiometric parameters in diff erent climates were identifi ed.Factors aff ecting leaf stoichiometry were assessed.The results show that R.pseudoacacia leaves were rich in nitrogen and defi cient in phosphorous during tree growth and development.Nitrogen and phosphorous levels in the soils of the loess region were lower than the average in soils in the rest of China.All ecological stoichiometric parameters of R.pseudoacacia leaves in two diff erent climates were considered“strictly homeostasis”.Precipitation,available phosphorus,and soil C:P were the main factors aff ecting the variation of C:N:P stoichiometry of R.pseudoacacia leaves.R.pseudoacacia in the loess hilly region has strong ecologically homeostatic characteristics and suggests that it is well-adapted to the area.

Shoot tissue culture of Robinia pseudoacacia f. decaisneana

Robinia pseudoacacia f. decaisneana is a transfiguration of Robinia pseudoacacia. For enhancing propagation coefficient of the species, the experiment of shoot tissue culture of Robinia pseudoacacia f. decaisneana was conducted in Forestry College of Shenyang Agricultural University from July 1999 to July 2001. The experiment included medium selection of explant induction survival, initial culture, subculture as well as rooting culture, and forming seedling with callus. The results showed that shoot segment in vitro survive rate is larger in spring than in autumn, and green dense callus could form plantlet. The best medium for initial culture was SH+0.5mg/L BA+0.05 mg/L NAA, with a propagation coefficient of 4.1 (per micro-cutting in a month), and for subculture it was B5+0.5 mg/L BA+0.05 mg/L NAA+ 10 mg/L Glu., with a propagation coefficient of 4.7. The best rooting medium was 1/2MS+0.5 mg/L NAA+10 mg/L Glu., with a rooting rate of 84.4%. These results provide reference data for reproduction of superior individuals of Robinia pseudoacacia f. decaisneana.

The runoff characteristics and harmonic analysis of the soil moisture dynamics in Robinia pseudoacacia stand

Robinia pseudoacacia stands act as a typical ecological protection forest in hilly semi-arid area of China. Two fields of surface runoff were separately set up in R. pseudoacacia stand and its clearcut area in the western Liaoning Province (1850-12225 E, 4024-4234 N) for measuring the characteristics of runoff and sediment as well as soil moisture dynamics. Contractive analysis of the two land types showed that there existed a significant difference in volumes of runoff and sediment between the sites of R. pseudoacacia stand and its clearcut area. The runoff volume and sediment volume in clearcut area were much bigger than those in R. pseudoacacia stand, with an increase amount of 40%-177% for runoff and 180%-400% for sediment. Hydrograph of surface runoff of typical rainfall showed that the peak value of runoff in R. pseudoacacia stand was decreased by 1.0-2.5?0-3m3s-1 compared with that in its clearcut area, and the occurring time of peak value of runoff in R. pseudoacacia stand was 10-20 min later than that in its clearcut area. Harmonic analysis of soil moisture dynamics indicated that the soil moisture in R. pseudoacacia stand was 2.3 % higher than that in clearcut area, and the soil moisture both in R. pseudoacacia stand and its clearcut area could be divided into dry season and humid season and varied periodically with annual rainfall precipitation. It was concluded that R. pseudoacacia stand plays a very important role in storing water, increasing soil moisture, and reducing surface runoff and soil erosion.

Photosynthetic Gas Exchange and Leaflet Movement of Robinia pseudoacacia in Relation to Changing Light Environments

On the sunny days, there were little diurnal changes in both azimuth and directional angle for either sun_ or shade_leaflet. However, there existed a significant diurnal change in midrib angle that reflected movements regarding evasion of light stress around noon hours. On the cloudy day, a very little diurnal difference was found in azimuth, directional and midrib angle. It is suggested that changing light environment is the main factor for inducing leaflet movement of Robinia pseudoacacia , and the rhythmical movement does not attribute to the leaflet movement. Leaf orientation control test showed that the photosynthetic rate ( Pn ), stomatal conductance ( g s ) and transpiration ( Tr ) of the artificial fixed_leaflets were significantly lower than that of control_leaflets. And the leaf temperature ( Tl ) of the fixed leaflets significantly exceeded that of control_leaflets, which may attribute to the significant difference of light interception between the fixed and control_leaflets. The light_dependent leaflet movement is the morphological adjustment of maintaining optimal physiological status.

Study on Relation between Endogenous Phytohormones and Ovule Abortion in Tetraploid Robinia pseudoacacia

This study was conducted to investigate ovule abortion of tetraploid Robinia pseudoacacia and its reasons. It was found that in the ovule development period of tetraploid R. pseudoacacia from 15 d after coronal opening, the levels of growth-promoting endogenous hormones in abortive ovules were lower than those in normal ovules, and the level of a growth-inhibiting hormone was always higher than those in normal ovules, indicating that ovule abortion of tetraploid R. pseudoacacia might be related to abnormal endogenous phytohormones in ovules. This study laid a foundation for further study on highly sterile phenomenon of tetraploid R. pseudoacacia seeds.

Correlation of eco-hydrographic benefit and height increment of Robinia pseudoacacia stand with climatic environmental factors in Yellow River Delta Wetland of China

The relationship between eco-hydrographic benefit of forest vegetation and climatic environmental factors is one of the focuses in the research on environmental protection and ecosystem countermeasures in Wetland. The runoff, sediment and soil moisture rate dynamics in Robinia pseudoacacia plantation and its clearcut area were investigated in the natural runoff experiment plots in Yellow River Delta Wet- land, Shandong Province, China. The correlation of height increment ofR. pseudoacacia with nine climate factors such as light, water, heat, etc. was analyzed by stepwise regression analysis. The results showed that the amounts of runoff and sediment in clearcut area of R. pseudoacacia were 53.9%-150.8% and 172.8%-387.1% higher than that in Robinia pseudoacacia plantation, respectively. The runoff peak value in R. pseudoacacia stand was obviously lower than that in clerarcut area, meantime, the occurrence of runoffpeak in R. pseudoacacia stand was 25 min later than in its clerarcut area. The soil moisture rates in R. pseudoacacia stand and its clearcut varied periodically with annual rainfall precipitation in both dry season and humid season. The annual mean soil moisture rate in R. pseudoacacia stand was 23.3%-25.6% higher than that in its clearcut area. Meanwhile, a regression model reflecting the correlation between the height increment of R. pseudoacacia and climatic factors was developed by stepwise regression procedure method. It showed that the light was the most important factor for the height increment ofR. pseudoacacia, followed by water and heat factors.

侵蚀环境生态恢复过程中人工刺槐林(Robinia pseudoacacia)土壤微生物量演变特征

采用时空互代法,以典型侵蚀环境纸坊沟流域生态恢复过程中不同年限的人工刺槐林为研究对象,选取坡耕地和天然侧柏林为参照,分析了植被恢复过程中土壤微生物量、呼吸强度、代谢商及理化性质的演变特征。结果表明,生态恢复过程中刺槐林土壤理化性质得到明显改善,微生物量随恢复年限的增加变化显著,10~15a后达到显著水平;并随年限逐渐增加,在近熟林和成熟林期基本达到稳定,成熟林后期又开始上升,恢复50a的刺槐林微生物量碳、氮、磷较坡耕地增加幅度分别为213%、201%和83%,但仅为天然侧柏林的50.98%、55.17%和61.48%。呼吸强度随恢复年限增加先升高后降低,与有机碳变化规律不同步;qCO2在恢复初期较坡耕地显著升高,随后迅速降低,25a后开始回落到坡耕地以下,50a后达到最低值,与天然侧柏林没有显著差异。相关性分析显示微生物量碳、氮、磷、qCO2与土壤养分和恢复年限相关性最为密切,达到显著（P〈0.05）或极显著水平（P〈0.01）。人工刺槐林促进生态恢复可以依靠生物的自肥作用恢复土壤肥力和增加微生物量,但要恢复到破坏前该地区顶级群落时的土壤微生物量和理化性状,还需要一个漫长的阶段,这个阶段可能需要上百年的时间。

滨海盐碱地刺槐(Robinia pseudoacacia)混交林土壤水盐动态

以固氮树种刺槐与绒毛白蜡、榆树、臭椿三树种的混交林及其纯林为研究对象,研究了刺槐与不同树种混交对土壤水分、盐分年动态变化的影响。研究结果表明：（1）刺槐与3个树种混交,刺槐臭椿混交林生长最好,均高于各自纯林。（2）混交林一定程度改善了土壤含水量及层次分布,土壤含水量整体趋势均表现出0~60cm表层土中含水量高于各自纯林,而深层土壤含水量低的特点,只有8月份纯林和混交林的土壤含水量没有显著差别。不同树种在具体层次上略有差异;（3）混交林降低了土壤含盐量,改变了土壤盐分层次分布和年变化规律。不同月份间土壤含盐量随土壤深度、混交树种的变化而变化。深层土壤含盐量高,表层土壤含盐量低,混交林含盐量低于纯林且存在树种差异。混交林与纯林含盐量均雨季低,旱季高;但在某一具体月份各层次含盐量差别不大;不同土层含水量、含盐量与天然降水之间有明显的相关性,天然降水是混交林及纯林土壤水分的主要来源。

国外刺槐(Robinia pseudoacacia)研究

综合论述了国外在刺槐林混交林、对当地生态系统的影响、饲料的营养价值、饲料林的管理、木材材性、固氮功能和刺槐凝集素等相关领域的研究动态和进展。刺槐和火炬松(Pinustaeda)、黑松(Pinusnigra)混交林是较理想的混交模式,并具较好的土壤的改良性能;此外,刺槐也是较理想的矿区植被恢复树种。刺槐的发展对当地植被的演替具有负作用,并影响当地鸟类的越冬。刺槐的饲料价值低于紫穗槐(Amphorafruticosa)和紫花苜蓿(Medicagosativa),高于地中海地区其他木本植物;刺槐林从第4或5年开始收获,生物量和饲料比例均较大。2年生的刺槐幼树,固氮量可达25.8g/株,接种根瘤菌可提高土壤中根瘤含量和林木生长量。刺槐生长具有异速性,心、边材组成结构比例、密度、硬度的不同,形成了木材的机械性能的差异。刺槐树皮凝集素为29kDa大分子,将其cDNA编码倒入烟草植物,可得以表达。

刺槐(Robinia pseudoacacia)无性系种群结构与生长动态的研究

研究了刺槐克隆种群的种群结构和生长动态.结果表明,刺槐克隆种群中幼年分株数量较多,死亡率较高;成年个体数量较少,死亡率较低,而且相对稳定,种群数量结构成金字塔型;无性系产生分株的时间较晚,分株的数量正处于上升阶段.无性系中刺槐基株的基径、高度、冠幅远远大于分株.刺槐分株在幼年时期高生长和冠幅的生长均较快,当生长到一定的年龄逐渐缓慢下来.克隆分株的生长、数量动态主要受克隆整合的内部调节机制和外部环境中灌木层、草本层竞争的影响.

Impacts of mixed litter decomposition from Robinia pseudoacacia and other tree species on C loss and nutrient release in the Loess Plateau of China

The productivity of Robinia pseudoacacia（R.p.） pure forest usually declines at the late growth stage,and reforming it into mixed forests could be a promising way to resolve this problem. When choosing a suitable tree species that can be mixed with R.p., the interspecific relationship is an important issue. Therefore, we gathered the autumn litter fall from R.p. and 10 other species from the Loess Plateau of China were mixed in dual species litterbags（R.p.＋each other species） and buried them in soil for a 345 days lab decay incubation. We measured the litter mass loss and nutrient contents to determine whether the nutrient release was affected by mixed species litter decomposition. The impacts of mixed litter decomposition on macro-elements release were more obvious than on micro-elements. The litters with similar substrate quality might show variable impacts on nutrients release in mixed decomposition. The C loss and release of nutrient was improved by descending order when R.p. litter was mixed with Hippophae rhamnoides, Ulmus pumila, Populus simonii, Larix principis-rupprechtii and Quercus liaotungensis（Q.l.）. But, except for Q.l., only the other species were recommended as suitable mix-plants for R.p. since promoting a high turnover of the nutrient in the litter compartment and a rapid availability for tree.

Accumulation of heavy metal in Platanus orientalis, Robinia pseudoacacia and Fraxinus rotundifolia

Plants are capable of reducing environmental pollutions through uptaking contaminants in their tissues. In the study site, twenty one-year-old leaves and shoots as well as twenty soil samples were sampled and analyzed by Inductively Coupled Plasma （ICP）. We investigated the uptaking ability of lead （Pb） and cadmium （Cd） by the leaves and shoots of Platanus orientalis, Robinia pseudoacacia and Fraxinus rotundifolia in Karaj city, the western Tehran, Iran. We also evaluated the total metal accumulation capacity by using metal accumulation index （MAI）. Results indicated that there was no significant difference in uptaking contents of Cd and Pb in the leaves among the trees. However accumulation of Cd in shoots of F. rotundifolia and R. pseudoacacia was significantly higher than that of P. orientalis. The accumulation of Pb in shoots of R. pseudoacacia was significantly higher than the other species. The amount of Pb in the soil of the study area was significantly higher than Cd. Concentrations of Cd and Pb in leaves of the three species are in the ranges of 2.4 2.7 mg Kg-1 and 7.1 14.4 mg Kg-1 , respectively. R. pseudoacacia had the highest MAI value for leaves （2.21） and F. rotundifolia had the highest MAI value for shoots （2.4）.

Cadmium and lead effects on chlorophyll fluorescence,chlorophyll pigments and proline of Robinia pseudoacacia

Heavy metal contamination is one of the most important abiotic stresses affecting physiological activities of plants.We investigated the effects of cadmium（Cd） and lead（Pb） on chlorophyll fluorescence（Fv/Fm,Fo,and Fm）,photosynthetic pigments（chlorophyll a and b）,and proline in one-year-old seedlings of Robinia pseudoacacia.The seedlings were treated twice over a period of 10 days with Cd and Pb at concentrations of 0,250,500,1000 and2000 mg L-1.Saline solution containing Cd and Pb was sprayed on the leaves.Chlorophyll and proline contents were measured after 10 days.Chlorophyll fluorescence of R.pseudoacacia was affected slightly by high concentrations（1000,2000 mg L-1） of Cd and Pb.Chlorophyll a and a/b increased at 1000 and 2000 mg L-1of Cd and proline content of leaves was similar in all treatments of Cd and Pb.Our results indicated that photosynthetic sensitivity of R.pseudoacacia to Cd and Pb contamination was weak.Photosystem II chlorophyll pigments were not damaged by Pb and Cd stress.We conclude that chlorophyll fluorescence along with chlorophyll and proline contents are useful indicators of Cd and Pb stresses in R.pseudoacacia which widely planted in urban polluted regions in Iran.

Effects of different supplements on tetraploid black locust (Robinia pseudoacacia L.) silage

Preparation of silage is a common method to preserve green forage. It plays an important role in improving forage utilization, solving the problem of forage provision and meeting the nutritional needs of livestock in winter and spring. The effects of various supplements on tetraploid black locust （Robinia pseudoacacia L.） silage were studied by analyzing its color, odor, texture, pH value, the composition and amount of organic acids, the ammonia-N/total-N ratio, crude protein, neutral detergent fibers and acid detergent fibers. Our results show that the silage quality of wilted tetraploid R. pseudoacacia preserved alone is acceptable, while adding brown sugar and Yishengkang to tetraploid R. pseudoacacia foliage improved its quality. The treatments consisting of the tet- raploid R. pseudoacacia mixed with 33% and 50% corn stalk achieved the best silage quality in terms ofpH value （p 〈 0.01）, amount of lactic acid （p 〈 0.01）, the ammonia-N/total-N ratio （p 〈 0.01） and the fermentation quality. These treatments also resulted in a high content of crude protein and lower amounts of acid detergent fibers. The treatment consisting of the tetraploid R. pseudoacacia mixed with 20% corn stalk was also good in the quality of its fermentation.

贵阳市刺槐(Robinia pseudoacacia L.)树附生苔藓植物初步调查

在"林城"贵阳,贵阳市行政区域内现有林地面积18.3万hm2,森林覆盖率为31.7%,森林覆盖率较高。树附生苔藓植物因其特殊性是可以作为城市大气污染的指示植物。树附生苔藓在贵阳分布较广泛,其中以作为贵阳市行道树或栽种树的刺槐树(Robinia pseudoacacia L.)最为典型。在贵州师范大学、花溪公园以及黔灵公园3个地点共选取了13棵刺槐树进行野外生态调查。结果发现了树附生苔藓植物8科12属14种。常见种为全缘刺疣藓Trichosteleum lutschianum(Broth.et Par.)Broth.、平锦藓Platygyrium repens(Brid.)B.S.G.、细叶小羽藓Haplocladium microphyllum(Hedw.)Broth.、矮锦藓Sematophyllum subhumile(C.Muell.)Fleisch.、真藓Bryum ar-genteumHedw.、异叶红叶藓Bryoerthrophyllum hostile(Herz.)Che和纤枝短月藓Brachymenium exile(Doz.etMolk.)Bosch et Lac.等。优势科为真藓科,其次是灰藓科,分别占总数的50%和37.5%。生活型只有矮丛集型和交织型。本次对贵阳市刺槐树附生苔藓的初步调查为进一步深入研究贵阳市树附生苔藓的多样性提供了基础资料。也是对将来监测贵阳市大气污染迈出的重要的第一步。

Assessing Adaptability of Planted Trees Using Leaf Traits: A Case Study with Robinia pseudoacacia L. in the Loess Plateau, China

Leaf trait patterns and their variations with climate are interpreted as an adaptive adjustment to environment.This study assessed the adaptability of planted black locust (Robinia pseudoacacia L.) based on the analysis of leaf traits and the comparison of its leaf traits with inter-specific ones existing in the same area.We measured some water and N use related leaf traits: leaf dry mass per unit area (LMA) and N,P and K concentrations based on both leaf area (Narea,Parea and Karea) and leaf mass (Nmass,Pmass and Kmass) of R.pseudoacacia at 31 sites along a water stress gradient in North Shaanxi Province,China.The results show that leaves of R.pseudoacacia have high Nmass and low LMA in the study area.High Nmass and low LMA are usually representative of luxurious resource use,and will advance plant resource competitiveness in high-resource conditions.As a whole,LMA-nutrient relationships of R.pseudoacacia display patterns that are fairly similar to the inter-specific relationships in both direction and intensity.The tendency for LMA and Narea to increase with decreasing water availability and the positive correlation between LMA and Narea reflect the trend for R.pseudoacacia to enhance water use efficiency (WUE) at the expense of down-regulated photosynthetic N use efficiency (PNUE) and high construction cost in dry conditions.However,the positive relationship between LMA and Narea in high mean annual precipitation (MAP) area is either unremarkable or reversed with decreasing water availability.This implies a lower photosynthetic capacity and a higher construction cost for high-LMA leaves.The inter-specific relationship between LMA and Narea is positive and does not change with water availability.This difference between inter-species and intra-species may be due to more diversified anatomies and more specialised structures for inter-species than intra-species.The failure of R.pseudoacacia adaption to dry conditions reflected by LMA-Narea relationship may be partially responsible for the emergence of rampike and dwarf forms found frequently in dry conditions.Incorporating intrinsic characteristics of planted trees into vegetation restoration project will be instructive and meaningful for species selection.

Black locust(Robinia pseudoacacia L.)as a multi-purpose tree species in Hungary and Romania:a review

Black locust(Robinia pseudoacacia L.) was the first North-American tree species imported to Europe at the beginning of the seventeenth century. It is commonly planted worldwide because of its adaptability to environmental stresses, its valuable wood, easy propagation, frequent and abundant seed production, excellent coppicing,high seedling survival, and relatively high wood yield. In Europe, Romania and Hungary have the most highly-developed black locust growing techniques and experiences.As a result of increasing interest in black locust in many countries, this review aims to provide a comprehensive overview of state-of-the-art site requirements, propagation, improvement and management(including growth and yield as well as use in energy plantations).

Nutrients of green and senesced leaves of a Robinia pseudoacacia plantation along a latitudinal gradient on the Loess Plateau,China

Plantations have been widely established to improve ecosystem services and functioning.Black locust,Robinia pseudoacacia L.is a common,widely planted species to control soil erosion on the Loess Plateau.Previous studies have focused on economic values but the interactions between soil and plant carbon(C),nitrogen(N)and phosphorus(P)remain unknown.Investigating variations of soil,green and senesced leaf C,N and P levels in R.pseudoacacia along a latitudinal gradient is useful to understanding its ecological functions.The results show that soil C,N and senesced leaf N and P significantly decreased with an increase in latitude,but there were no significant changes in the senesced leaf C and soil P.The resorption efficiency of N was related with latitude and soil N levels,and the relation between green leaf N and soil N was significant.These relations suggest that soil N was the key in affecting green leaf N levels.At higher latitudes,senesced leaves had lower N levels associated with higher N resorption efficiency to maintain a stable N content in green leaves.With a decrease of soil N,R.pseudoacacia can enhance N resorption efficiency to meet the demand of growth.Thus,it is an important species for reforestation,especially in nutrient-poor environments.

Increased salinity and groundwater levels lead to degradation of the Robinia pseudoacacia forest in the Yellow River Delta

Forest degradation is a worldwide problem,although its causes vary due to geographical and climatic differences and man-made causes.In recent years,the Robinia pseudoacacia forest in the Yellow River Delta has suffered severe degradation.The causative mechanisms were investigated in the field over two years,and the results show that increased forest degradation was reflected by increased tree mortality,high leaf and soil sodium salt levels and groundwater depth.Average tree diameters decreased,and leaf chlorophyll and soil microbial contents decreased.Redundancy discriminate analysis(RDA)showed that degradation of the forest was correlated positively with soil salt content,but negatively with groundwater depth.Correlation analysis showed that 0.79%–0.95%soil salt content and above 1.20 m groundwater depth caused the death of R.pseudoacacia trees due to localized anthropogenic economic activities,such as rice farming,that disrupted the original water–salt balance.Measures are recommended to prevent further degradation and restore degraded forests.