为保持上海地区佛甲草(Sedum lineare Thunb.)轻型屋顶绿化的越夏景观效果,实现低维护生态效益,对佛甲草屋顶越夏进行观测.参考美国草坪评价方法(National Turfgrass Evaluation Program,NTEP)对其景观效果开展分阶段评分,将评分结果与同期小气候环境参数进行Spearman相关性分析,对与评分值显著相关的小气候参数进行主成分分析,得到有效环境参数,并在综合考虑环境参数的可获取性后筛选出关键环境参数,以探析佛甲草景观变化的临界点及其相应的小气候环境的变化特征,进而总结归纳出佛甲草需加以灌溉养护时的小气候条件.研究表明:有效环境参数为日均气温、日均基质温度、日最高温、日最低温、日降水量、日光合有效辐射和空气湿度,分别表征温度、辐射和湿度;筛选后得到日最高温、日最低温和降水量三项关键环境参数;在上海夏季日最高温35℃左右、日最低温25℃以上的高温胁迫下,连续4日无降雨即可使佛甲草景观效果降至可接受水平之下.上海地区佛甲草屋顶绿化的视觉景观质量与环境温湿度条件显著相关;越夏养护的关键时间点在7月中下旬,夏季养护阶段需持续至9月初;在此期间,若连续3日气温上升、日最高温达35℃、日最低温达25℃,且无降雨过程时,应及时进行灌溉养护.

本文以上海市民立中学设置12年的屋顶花园为研究对象,探讨该屋顶花园中的植物多样性.调查发现该屋顶花园中目前存在31科54属57种陆生高等植物,其中以蔷薇科和百合科为最多,其次分别为木犀科、豆科、十字花科、唇形科、禾本科等,植物类型包括乔木、灌木、藤本和草本四种.结果表明,民立中学屋顶花园的物种多样性程度较高,乔灌草搭配合理,部分物种是通过风、鸟等非人类因素迁入,其生态效益显著.

植物体外雄核发育(androgenesis)是植物的花粉粒或游离小孢子在人工诱导条件下,偏离原来的发育途径经连续的细胞分裂发育成胚再生单倍体,后者通过染色体加倍可以获得纯合二倍体,对于植物的发育机理研究和遗传育种应用具有重要的意义.本文对植物体外雄核发育的细胞学事件及其影响因素进行了回顾,重点论述雄核发育的小孢子分裂方式和发育途径,围绕供体植物的基因型、生理状态、小孢子发育时期、诱导处理和培养条件等对雄核发育效率的影响进行探讨,并进一步论述体外雄核发育在单倍体和双单倍体生产中的应用及其限制因素,以为加快植物育种进程提供理论依据.

Biomass energy from renewable resources has been considered an alternative source of energy, and the growing contribution of biomass to the world energy also gives a new way to solve the problems such as global warming, the soaring fuel costs and environmental pollution. Lignocellulose is the main component of plant cell walls and is also one of the most abundant renewable resources on earth. Lignocellulosic biomass is principally composed of cellulose, hemicellulose and lignin, which can be converted into liquid biofuels such as bioethanol. The linkages between lignin and carbohydrates (hemicellulose and cellulose) are formed by ester, ether and glycosidic types of bonds, which formed a kind of covalently bonded aggregates called lignin-carbohydrate complex. The compositions of biomass and interaction of these components in the cell wall affect the hydrolysis of carbohydrates, and then determine the efficiency of lignocelluosic biomass utilization. Although lignin is one of the most abundant components in the lignocellulosic biomass besides polysaccharides, it has been considered as a physical barrier to prevent enzyme access to cellulose structure. Therefore, to improve the biomass production in the field and the effects of the factory conversions of biomass into biofuel are the two most concerned issues. That is, how to improve the utilization of lignin efficiency has been becoming a hot issue of biorefinery in biomass energy development. In this paper, the characteristics of development and sedimentary of lignin in plant cell walls, genetic improvement and genetic modification of lignin trait in bioenergy crops have been systematically reviewed, which is mainly from the point of view of cutting the lignin to enhance the overall lignocellulosic biorefinery. To select low-lignin-content energy crops, considerable genetic improvements can be expected through traditional breeding program or down regulation the levels of enzymes involved in the reactions specific for lignin monomer synthesis, which would reduce the amount of chemicals and energy used in pretreatment in lignocellulosic biorefinery. Furthermore, to explore the optimization of lignocellulose characters and the possibility of increased biofuel production rate, the technological means of biological refining pretreatment, transformation and biofuel production have been discussed for overcoming the cost barrier of lignocellulosic biomass utilization in the purpose of loosening lignin’s grip. Several different pretreatment and fractionation processes such as acid, alkaline and organic solvent hydrolysis can be used for treatment of lignocellulosic materials. And successful pretreatment can significantly improve the hydrolysis and increase the yield of bioethanol. In addition, the perspectives on hot issues and biofuel industry involved in studies of lignin were discussed.

细胞质雄性不育系是作物杂种优势利用的有效途径,分离其不育系线粒体和叶绿体基因组是深入探究细胞质雄性不育分子机制的重要环节,本研究以紫花苜蓿细胞质雄性不育系CMSI和野生对照植株WT为研究材料,选取新鲜叶片经冷冻匀浆、差速离心分离叶绿体和线粒体、DNase I降解核DNA、蛋白酶K裂解线粒体和叶绿体、酚—氯仿—异戊醇去除蛋白质和用乙醇沉淀叶绿体DNA (cpDNA)和线粒体DNA (mtDNA),结果如下:(1)叶绿体提取液中叶绿体数量的平均值为1 500个/mL,而詹纳斯绿B染色观察发现提取液中线粒体结构完整、含量较多;(2)叶片取材量为4 g时,CMS1 (WT)的cpDNA平均产率为0.41 (0.47)μg/g,而mtDNA的平均产率为1.15 (0.83) μg/g;改进叶片取材量为10 g时,两种苜蓿材料的cpDNA和mtDNA的平均产率升高至2.17 μg/g和2.22 μg/g,并且纯度好(cpDNA和mtDNA的OD260/OD280均保持在2.0左右);延长蛋白酶K消化处理时间(2h,4h和6h)可以提高紫花苜蓿cpDNA和mtDNA的产率,其中消化4h的mtDNA质量浓度最高(59.9 ng/μL),而cpDNA浓度则在孵育6h后达到最高值24.3 ng/μL;(3)紫花苜蓿CMS1和WT的mtD-NA和cpDNA琼脂糖凝胶电泳检测发现,细胞质基因组条带清晰,无拖尾现象,进一步表明采用以上方法提取的紫花苜蓿mtDNA和cpDNA符合分子遗传学研究的标准和要求.

Heavy metal ( HM ) toxicity is a worldwide concern because it damages plants by altering their major physiological and metabolic processes. The heavy metal cadmium ( Cd) is a nonessential element, and is a valid inhibitor of plant growth. The toxic effect of cadmium is closely related to its transfer from the soil to the plant above ground parts. Understanding the transport pathway and regulatory mechanism of cadmium in plants may improve plant resistance to this heavy metal, in addition to providing a theoretical basis for the phytoremediation soils contaminated by cadmium. In this paper, we reviewed the transport pathways of Cd2+ in plants and what limits its mobility based on the cytological structural and molecular regulation mechanism of plants. As the main organ for transporting water and nutrients to the plant body, the plant root is also the main organ that absorbs toxic metals, such as cadmium. During the process of Cd2+ transfer from the root cortex to the xylem, most Cd2+is deposited between the cells of the root cortex, with some reaching stele, before being transferred to the plant organs, such as the leaves in the above ground part of the plant. The transport pathway of Cd2+through the root cortex is mainly apoplastic, with the cytoplasmic accumulation of Cd2+possibly causing apoplastic transport towards the vascular cylinder to decline. The transport pathway of Cd2+ in the vascular cylinder is also mostly apoplastic, with cytoplasmic accumulation reducing Cd2+ transfer to the xylem. Since the aboveground parts of plants are more susceptible to Cd2+ poisoning, two cellular strategies to restrict the absorption and transfer of cadmium have evolved. First, the Casparian strip surrounding radial wall and the endodermis wall prevents Cd2+ from entering the root xylem via the apoplastic pathway. In addition, the Casparian strip promotes Cd2+ transport via the endodermis, leading to vacuolar isolation and cytoplasmic precipitation. Second, heavy metal detoxification occurs by chelating Cd2+ to form stable compounds, which are then deposited inside the vacuole. Third, excess cadmium also activates oxidative stress defense mechanisms and the synthesis of heavy metal stress related proteins to minimize metal toxicity, which includes the use of metallothiones and ion channels, such as H+/Cd2+binding or sequestrating Cd2+into vacuoles. For systematic improvements in the phytoremediation of heavy metal pollution, a more comprehensive understanding of cellular mechanisms involved in Cd avoidance, uptake, transport, and accumulation is required. Furthermore, the excluder strategy by extensive sequestration and retranslocation of cadmium through symplastic and apoplastic pathways should be confirmed and explored in future studies.

青藏高原高寒草原生态系统是我国特有的生态系统类型,由于受到人为破坏的影响,目前该地区草原生态系统功能退化,优良牧草减少,有毒植物蔓延.高原鼠兔(Ochotona curzoniae)和高原鼢鼠(Myospalax baileyi)是青藏高原东缘高寒草原中最重要的两种小型哺乳动物,其采食行为和挖掘洞穴的生活特性必然对生态系统产生影响,但其与有毒植物之间的互作关系尚未揭示.基于此,在甘肃省玛曲县河曲马场自然生长的高寒草原生态系统中开展了有毒植物的分布与高原鼠兔、高原鼢鼠之间的相关性研究.结果表明,该高寒草原生态系统中分布有毒植物27种,分属于菊科、豆科、毛茛科等11科.在此基础上,测定了该地区有毒植物的生物多样性指数、均匀度指数和丰富度指数,并探究了单位面积条件下有毒植物的分布特征与高原鼠兔和高原鼢鼠种群密度之间的相关性,发现该地区高寒草原有毒植物的蔓延与高原鼠兔的密度之间存在密切的负相关关系(P＜0.05),而与高原鼢鼠的相关性不显著(P＞0.05).

To understand the effects of CdCl2 stress to seed germination in alfalfa (Medicago sativa) is important for its bioremediation of heavy metal. Using the petri dish germination method,the effects of different concentrations of CdCl2 (0,5,10,20,40 and 80 mg/L) treated with alfalfa seed germination were studied under three conditions of pH (4. 0,6. 0 and 8. 0) . The results showed that the treatments with low concentrations of CdCl2 (≤20 mg/L) significantly improved the seed germination rate,germination potential,germination index and vigor index. Compared to the control group,the vigor index greatly increased up to 177. 52 ± 16. 61 under the treatments of concentration of CdCl2 was 20 mg/L (pH 6. 0) . The promotion for root length,shoot length,root fresh weight and shoot fresh weight were also strengthened with the increasing concentration under 20 mg/L CdCl2. Treated with concentration of CdCl2 was 20mg/L under pH 4. 0,pH 6. 0 and pH 8. 0,the shoot fresh weight was (6. 60 ± 0. 11),(6. 68 ± 0. 20) and (9. 51 ± 0. 16) mg,while root fresh weight was (6. 71 ± 0. 10),(7. 09 ± 0. 08) and (9. 10 ± 0. 08) mg,up to the maximum respectively. The seed germination and seedling growth of alfalfa were significantly inhibited as CdCl2 concentration increased (40 and 80 mg/L) . Under 80 mg/L,the germination rate and vigor index of alfalfa seed were only 14. 8% and 46. 5% of those of controls,and shoot fresh weight decreased to (3. 48 ±0. 15),(4. 03 ±0. 19) and (7. 00 ±0. 22) mg under pH 4. 0,pH 6. 0 and pH 8. 0,all down to the minimum respectively. The germination rate and vigor index of alfalfa seed decreased with the decrease of pH. Treated with concentration of CdCl2was 80 mg/L under weak base (pH 8. 0) condition,the germination rate (66. 40% ± 3. 19%) was higher than those treated with strong acid (pH 4. 0) (11. 20% ± 3. 61%) and weak acid (pH 6. 0) (9. 20% ±4. 22%),while the vigor index (93. 90 ± 10. 71) was also higher than those under pH 4. 0 (49. 77 ± 3. 25) and pH 6. 0 (56. 67 ±3. 48),respectively. The results indicated that adjust of the environment from acid to alkaline could alleviate CdCl2toxicity to seed germination and seedling growth in alfalfa.

Alfalfa(Medicago sativa) is a typical perennial autotetraploid and outcrossing plant.The sexual reproduction of alfalfa is susceptible various factors,and its original genetic integrity is easy to lose.Vegetative propagation of alfalfa by stem cutting is extremly important to ensure the genetic stability of alfalfa resources and cultivars.In this research,taking male sterile mutant(ms1) identified in alfalfa as experimental material,the effects of different growth regulator treatments and culture mediums on its clonal propagation were studied.The results showed that,there were significant differences among treatments of three growth regulators on the clonal propagation(P0.05).The efficiency of ABT was the best for the regeneration,and then followed by NAA and IBA.The highest rooting rate reached under treatment of 150 mg·L-1 ABT.Under this treatment,the survival rate was up to 88.3%,which was 71.0% higher than that of the control(P0.05),and also exhibited the good performance of numbers of root(3.94),root length(8.96 cm),rooting effect(0.74) and numbers of leaf(10.46).The survival rate of all the cuttings was not significant different among the five culture mediums(P0.05),while significant differences in the numbers of root,root length,rooting effect and numbers of leaf were found(P0.05).The mixed culture medium was better than the single culture medium,which provided a good support for the growth of cloning plants,and the efficiency of M4(soil + vermiculite + perlite) and M5(soil + sand + perlite) were the best compared to the single garden soil.

Pollen is the foundation of plant reproduction,and successful release of pollen is essential for plant reproduction.Due to the complexity and the diversity of the process of pollen release in papilionaceous plants, the picture of the physiological and the mechanical mechanisms in pollen release is still incomplete.In this paper,the mechanism of pollen release in papilionceous plants is reviewed.The pollen release in papilionceous plants is a complex process,which includes a physiological process(internal release)and a mechanical(or physical)process(extrinsic release).The physiological process of pollen release includes anther formation and anther dehiscence.The formation of viable pollen depends on accurate execution of developmental programmes, and the tapetum cells are essential for the development of the pollen grain.In the case of anther dehiscence, four types of anther wall have been observed in papilionaceous plants including basic type,monocotyledonous type,dicotyledonous type and reduced type.The mechanical process of pollen release shows that there are four patterns in papilionaceous plants:the explosive model,piston model,brush model,and valvular model.Comparisons of pollination efficiency made between these models,showed that the piston and valvular models may be the two basic evolutionary branches of pollen release in papilionaceous plants.The spatial and temporal patterns of pollen release are still a hotspot of evolution in papilionaceous plants and are related to flower morphology,pollination biology and mating system.

In the Hupfer method, the P fraction is classified as NH4Cl-P (loosely adsorbed P), BD-P (Fe-P), NaOH-P (Al-P), HCl-P (Ca-P) and residual-P. We extensively extracted the P fraction data from previous pub-lished papers and analyzed all the data together. The results show that total phosphorus (TP) was significantly correlated with NH4Cl-P, BD-P, NaOH-P, HCl-P and residual-P (P<0.001). Quadratic relationships were found between TP and NH4Cl-P, BD-P and HCl-P. There were significant linear relationships between TP and NaOH-P and residual-P. Furthermore, the native P content of sediments, external sources of P loading, resuspension of sediment particles and redox potentials were demonstrated as major factors influencing P distribution. This study provides a novel insight into the mutual correlation of each P composition and will help identify the hotspots of P release region by using fractionation and TP under favorable conditions.

Fifty four alfalfa cultivars were studied in a greenhouse with 2 cutting treatments.ANOVA and cluster analysis based on biomass,cell wall component(cellulose,hemicellulose and lignin) content,plant height, branches and stem/leaf showed the following results:1) there were significant differences for all biofuel traits such as biomass and cell wall compositions between 54 alfalfa cultivars(P<0.01),and the variations within varieties were higher than those among varieties;2) the variation coefficients of biomass and cell wall compositions analyzed in these 54 alfalfa cultivars showed that biomass(42.42%)>content of lignin(17.22%)>content of cellulose(12.74%)>content of hemicellulose(10.04%);3) The content of hemicellulose was significantly affected by cutting treatment,but not for biomass,content of cellulose and lignin;4) Cluster analysis based on biofuel traits divided 54 alfalfa cultivars into 5 groups,of which the groupⅡand the groupⅤhad the highest biomass production performance,and the latter group showed better regeneration.In this study,the comprehensive analysis based on yield production,contents of cellulose,hemicellulose and lignin showed that 8 cultivars-Gannong No.3, Huangyangzhen,WL903,Hetian,Sanditi,Pingliang,Dayushan and Italian alfalfa-could be potential materials for improving alfalfa as a biofuel feedstock in future breeding programs

紫花苜蓿(Medicago sativaL.)是世界上最重要的豆科牧草之一,利用雄性不育系获得杂种优势,可以有效提高紫花苜蓿产量、抗逆性和品质,因此开展紫花苜蓿雄性不育机制研究和杂交制种应用,对于紫花苜蓿产业发展具有重要意义。本文就目前国内外紫花苜蓿雄性不育机制研究及其应用进展做一回顾,包括紫花苜蓿雄性不育类型及其遗传机制、雄性不育细胞发育和生理生化机制以及雄性不育基因定位研究进展等方面,并对紫花苜蓿雄性不育杂交制种现状及其应用前景进行了展望。

Arbuscular mycorrhizae(AM) is a widely distributed plant-fungal symbiosis in natural ecosystem.Herbivore is a general ecological process in grassland ecosystem.In order to discover the ecological stretegies among AM fungi-plant-animal,the interrelation between AM fungi and herbivore and the response of host plant on their cooperative effects were studied in this review,and three points were discussed:1) the research about herbivore on AM fungi colonization and AM fungi spores population,2) the influence of AM on animals behaviors,especially the Insects gather their foods,and 3) the responses of plants to their cooperative effects.Finally research perspectives were also given out in this field.

【目的】紫花苜蓿的育性特征与种子产量紧密相关,研究紫花苜蓿不同亚（变）种的育性遗传变异可为紫花苜蓿育性基因定位和种子生产提供基础数据。【方法】2007-2008年,利用TTC染色法和生物统计学方法对3个紫花苜蓿亚种,包括黄花苜蓿（Medicago sativa subsp.falcata）、紫花苜蓿（M.sativa subsp.sativa）和蓝花苜蓿（M.sativa subsp.caerulea）,以及1个紫花苜蓿变种杂花苜蓿（M.sativa var.media）共计9个品种的花粉活力、胚珠数和结实率进行了观察,并研究分析了不同品种花粉活力与胚珠数的遗传变异以及与结实率之间的相关性。【结果】（1）花粉活力和胚珠数的变异分析结果表明,不同紫花苜蓿品种花粉活力和胚珠数存在显著差异,其中紫花苜蓿（匈牙利）花粉活力和胚珠数最高,达85.48%和13个/小花;（2）自交结荚率与花粉活力呈极显著线性正相关（P〈0.01）,而人工授粉结荚率与胚珠数呈显著线性正相关（P〈0.05）;（3）在自交与人工授粉条件下,苜蓿品种结实率呈现种间变异大于种内变异趋势,而自然授粉条件下则呈现种内变异大于种间变异,表明苜蓿属植物授粉方式与结实率紧密相关,且自交结实率〈人工授粉结实率〈自然授粉结实率。【结论】紫花苜蓿亚（变）种花粉活力和胚珠数具有丰富的遗传多样性,且分别在自交和人工授粉方式下与苜蓿的结实率显著正相关。

【Objective】 The aim of the present study was to reveal the genetic variation of fertility and the relationship with seed set of three subspecies and one varieties of Medicago sativa, offering theoretical reference for selecting and breeding of superior species. 【Method】 In this paper, genetic variations of pollen vigor and ovule numbers in nine 9 varieties of Medicago sativa belong to M. sativa subsp. falcate, M. sativa subsp. sativa, M. sativa subsp. caerulea and M. sativa var. media were studied. From 2007 to 2008, the pollen vigor, number of ovules per flower and their relationships with seed set were investigated respectively. 【Result】 There existed significant difference (P0.05) in pollen vigor and ovules per flower among these Medicago sativa plants, and the highest pollen vigor and ovules per flower were observed in Hungary (M. sativa subsp. sativa) with 85.48% and 13, respectively. According to the correlation analysis, the seeds set under self-pollination showed a significant linear correlation with pollen vigor (P 0.01), while seed set under artificial-pollination showed a significant linear correlation with ovules per flower (P0.05). The variations of seed set among-varieties were larger than those of within-variety under self-pollination and artificial pollination, but variations of seed set within-varieties were larger than those among-varieties under open pollination. The results indicated that the ways of pollination had significant effects on seed set in Medicago sativa plants, and the number of seeds per inflorescence was self pollinationartificial pollinationopen pollination. 【Conclusion】 The high genetic polymorphisms of pollen vigor and ovules per flower in Medicago sativa were observed. There was a positive correlation between seed set and pollen vigor under self pollination as well as ovules per flower under artificial pollination.

将不同品种的优良性状通过品种间的杂交集中到一个品种中是育种工作的主要目标,而利用基因型选择代替传统的表型选择将大大加快育种进程和提高育种效率,其中,DNA标记的获得是进行DNA标记辅助育种的重点。随着作物分子标记辅助育种技术的快速发展,苜蓿（Medicagosativa L.）重要性状关联的分子标记研究也取得了很大进展。本文就苜蓿草产量、抗病（虫）害、抗逆性和繁殖特性等主要农艺性状关联的分子标记研究进展进行了综述,主要包括RFLP（DNA-DNA杂交）、RAPD和SSR（PCR）以及AFLP（PCR与限制性酶切技术结合）等分子标记,最后还就苜蓿分子标记辅助育种（marker assisted selection,MAS）所面临的限制因素及其在苜蓿品种改良中的应用前景进行了探讨。

The aim of this work is to develop a method of plant regeneration from leaf explants of Platanus occidentalis L. successfully. Woody plant medium (HortScience 16:453–459, 1981) and Murashige and Skoog (Physiol Plant 15:473–497, 1962) medium were used as induced and rooted basal medium, respectively. The effects of combinations of 6-BA, IBA, NAA and KT with different concentrations on adventitious bud regeneration from P. occidentalis leaf explants were compared. The results showed that the highest shoot regeneration frequency (90%) and maximum number (13.72 ± 0.44) of shoots per explant was recorded on WPM medium supplemented with 22.20 mmol l−1 6-BA and 0.49 mmol l−1 IBA. A 40-day-old explants were much more productive for shoot formation than others in this study. The regenerated shoots were cultured on MS medium supplemented with 1.33 mmol l−1 6-BA, 0.16 mmol l−1 NAA and 2% (w/v) adenine, after 2-week shoots were transferred to 1/2 MS medium supplemented with 0.49 mmol l−1 IBA for rooting. Hardened plantlets via acclimatization were transferred to pots and transplanted to the soil finally. To ascertain whether tissue culture had effects on the genetic stability of plantlets regenerated, the genetic diversity was assessed using RAPD marker. A total of 96 bands ranging from 0.5 to 2.2 kb with an average of 6.4 bands per primer, were obtained using 15 primers. Amplified products exhibited few of polymorphic patterns across all the plants of P. occidentalis and the overall frequency of detection of somaclonal polymorphisms was lower than 0.0104%.

Alfalfa (Medicago sativa L.) belongs to the typical allogamy,and the sampling strategies are closely related to its molecular genetic diversity analysis. Four alfalfa varieties,Longdong (local variety), Zhonglan 1 (synthetic variety),Graze and Queen (introduced variety),were selected and their bulked DNA samples obtained from 10,20,40 and 60 individual plants,respectively. The results of unweighted pair-group method with arithmetic averages (UPGMA)analysis based on random amplification polymorphic DNA (RAPD)and simple sequence repeat (SSR)markers showed that 40 and 60 bulked DNA sample methods had the same genetic relationships between these 4 alfalfa varieties, which indicated that populations with 10 and 20 individual plants were too small,and the accurate analysis were positive related to the sampling numbers but the cost of analysis increased also. According to the results above,40 individual plants was the suitable sampling strategies in genetic diversity analysis of alfalfa based on RAPD and SSR markers.