高羊茅植株再生体系的研究与建立

利用幼苗下胚轴建立了高羊茅(FestucaarundinaceaSchreb.)植株再生体系。当高羊茅种子以次氯酸钠为主要消毒剂时,其最适的浓度和时间分别为次氯酸钠50%(V/V)处理20min,种子发芽率为80%,污染率为0%。研究发现用高羊茅下胚轴诱导愈伤组织时,下胚轴的不同的切法对愈伤组织诱导有影响,从一端切的下胚轴诱导愈伤率74.7%高于从两端切55.8%。以下胚轴为外植体,2,4D的浓度为9mg·L1时,愈伤组织诱导率最高。高羊茅愈伤组织的分化再生率可达80.7%。     

大叶秦艽的组织培养与植株再生

以秦艽的叶和下胚轴为外植体,成功地诱导出愈伤组织和再生植株.诱导愈伤组织最合适的培养基为附加2 m g·L- 1 2 ,4 - D和0 .5 mg·L- 1 6 - BA的MS培养基,诱导率可达到10 0 % .愈伤组织转移到附加2 mg·L- 12 ,4 - D和0 .5 mg·L- 1 KT和5 0 0 m g·L- 1 L H的MS培养基上进行继代培养,增殖后的愈伤组织转移到附加0 .1mg·L- 1 2 ,4 - D和0 .5 m g·L- 1 6 - BA的MS分化培养基上进行分化,其分化率可达到86 .6 7% ,将分化出的芽转接到不加激素的MS上,结果可生长出大量的分化苗.     

影响沙田柚叶片离体培养的因素研究

研究了离体培养条件下影响沙田柚叶片愈伤组织诱导和分化的一些因素。结果表明 ,2 ,4 D可以诱导愈伤组织的形成 ,高浓度的蔗糖 (6% )显著提高叶片愈伤诱导率与愈伤组织重量 ,且在 2 ,4 D和蔗糖之间存在着相互作用。外源GA3处理抑制愈伤组织的诱导和生长 ,而CCC与ABA处理显著提高叶片的愈伤诱导率和愈伤组织生长量。愈伤组织转移到附加 3 .0mg/LBA的MS分化培养基上可以分化出芽 ,0 .2 5mg/LGA3的加入可以进一步提高愈伤组织的分化率和每块愈伤组织的再生芽数。     

扁桃愈伤组织诱导及分化的研究

以扁桃优良品种'Naporeil'的茎段、叶片和花药作为外殖体,分别对其进行愈伤组织诱导和分化研究,以筛选愈伤组织的最佳诱导增殖培养基、分化培养基和生根培养基.结果表明,该品种以茎段、花药作为外殖体最易诱导获得愈伤组织,叶片不适宜作为外殖体诱导愈伤组织;愈伤组织的最佳诱导增殖培养基均为B5+0.5 mg/L 2,4-D+0.2 mg/L 6-BA+1.0 mg/L NAA,愈伤组织诱导率为100%,增殖倍数最高可达7倍;茎段愈伤组织的分化培养基为MS+0.2 mg/L NAA+0.8 mg/L 6-BA+0.5 mg/L ZT,分化率为71%;花药愈伤组织未见分化.由茎段愈伤组织再分化获得的不定芽在1/2MS+0.5 mg/L IBA培养基上诱导生根,并给以黑暗预处理可使生根率达80%以上.     

新疆雪莲植株再生体系研究初探

以新疆雪莲叶片、叶柄和根为外植体,诱导新疆雪莲植株再生,获得愈伤组织诱导、分化和生根最佳培养基,并初步建立其再生体系.研究结果表明:所用培养基均能诱导出愈伤组织且诱导率最高可达100%,分化率最高可达78%.对不同外植体的愈伤组织诱导结果表明:叶片和叶柄的诱导效果最好,根的诱导效果较差.其中对叶片愈伤组织诱导效果最好的培养基是MS+NAA0.50 mg/L+2,4-D0.10 mg/L+6-BA1.00mg/L,对叶柄的诱导效果最好的培养基是MS+NAA1.00mg/L+2,4-D0.10mg/L+6-BA0.10mg/L;分化培养基以MS+NAA0.20 mg/L+6-BA1.00mg/L较适宜,生根培养基以1/2MS0+NAA1.00mg/L较适宜.     

芝麻愈伤组织诱导与植株再生体系的建立

以芝麻栽培种(Sesamum indicum, 2n=26)、野生种(S. radiatum, 2n=64; S. schinzianum, 2n=64)及其远源杂交后代(S. schinzianum × S. indicum)为材料, 研究了不同基因型、外植体类型、激素种类及其浓度对芝麻愈伤组织诱导及植株再生的影响, 建立了芝麻愈伤组织诱导及高频植株再生的技术体系。结果表明, 6-BA/NAA激素组合有利于绿色紧密型愈伤组织的形成及分化; 最佳愈伤组织诱导及分化培养基为MS+ 0.1 mg·L^–1NAA + 2.0 mg·L^–16-BA+ 30 g·L^–1蔗糖。在该培养条件下, 野生种下胚轴愈伤组织的诱导率最高为97.50%, 分化率为94.02%; 栽培种下胚轴愈伤组织的诱导率最高为40.60%, 分化率为8.16%; 远缘杂交后代幼胚外植体愈伤组织的诱导率最高为46.67%, 分化率为89.29%。该研究结果为芝麻转基因技术体系的建立及新种质创制奠定了基础。     

牛蒡组织培养和高频植株再生的研究

通过对牛蒡(A rctium lapp a L.)不同外植体、不同激素配比的比较研究,建立了牛蒡离体培养高效植株再生体系.牛蒡子叶与下胚轴切段在含2.0 m g/L 2,4-D和0.5~2.0 m g/L BA的M S培养基中愈伤组织诱导率可以达到87%~100%;在1.0~3.0 m g/L NAA和0.5~2.0 m g/L BA的M S培养基上通过愈伤组织间接分化或外植体直接分化形成不定芽,其中愈伤组织分化率可达100%;下胚轴的分化率明显高于子叶,在1.0 m g/L NAA和1.0 m g/L BA的M S培养基上下胚轴直接分化率达77.3%.组织学观察发现牛蒡再生有器官发生和体细胞胚发生两种途径.将生长状态良好的不定芽转至含1.0 m g/L IBA和1.0 m g/L NAA的1/2 M S培养基上生根,移栽,成活率达到93.3%.从诱导愈伤组织到组培苗在珍珠岩中过渡成活,大约需要13周.组培苗次年开花并结实,生长形态特征正常.     

影响魔芋愈伤组织形成的几个因素

研究了魔芋不同外植体类型、激素种类和激素组合、光暗培养条件、不同生理时期取材等因素对愈伤组织诱导能力的影响以及不同处理所得愈伤组织的分化能力。结果表明 ,不同外植体类型诱导愈伤组织能力顺序为 :顶花芽 >幼嫩芽鞘 >子芋 >根状芋 ;经过 4℃低温预处理的子芋和根状芋比未经预处理的外植体更易诱导出愈伤组织 ;MS +BA1 .0～ 2 .0 +NAA1 .0～ 2 .0培养基均能诱导外植体产生愈伤组织 ,愈伤组织诱导率大多在 5 0 %以上 ,最高达 87.5 % ;在魔芋生长期取材比在休眠期取材更易诱导出愈伤组织 ;不同处理所得愈伤组织在分化能力上具有较明显的差异。     

虎杖愈伤组织的诱导及高产白藜芦醇材料的筛选

将虎杖(Polygonum cuspidatum)不同外植体经不同消毒时间处理后,接种在添加不同激素种类和水平的相同基本培养基上或相同激素种类和水平基本培养基上进行诱导实验,同时对根、根茎芽、叶、韧皮诱导的愈伤组织进行白藜芦醇的含量测定实验,其结果表明:基本培养基以MS较好,外植体叶对激素种类较为敏感,其中适当浓度的NAA诱导愈伤组织比2,4-D的效果要好,KT比BA要好,在有KT存在的培养基上诱导愈伤组织比较紧密,有利于分化;在MS NAA2m g/L KT0.1mg/L培养基上诱导愈伤组织较好,根茎芽的诱导率最高,为73%.愈伤组织的生长趋势从接种的第3d开始生长,到21d时生长达到最高峰,干重为0.461g,以后生长速度减慢.不同材料诱导的愈伤组织中白藜芦醇的含量以根茎部芽的愈伤组织含白藜芦醇最高,其次是叶和根,最低的为韧皮.     

大花萱草不同外植体诱导愈伤组织的比较研究

选取4个萱草品种（H.hybrida Stella D＇Oro,H.hybrida pink Charm,H.hybrida Bayley Hay,H.hybrida Frans Hal）进行不同外植体诱导愈伤组织的研究.接种萱草叶片、根段、茎尖和子房花药几种外植体诱导愈伤组织发现：茎尖诱导愈伤组织的效果最好;叶片取材方便但是诱导率相对较低;根段较难诱导愈伤组织;子房和花药受取材时间限制且污染率较高,但是愈伤组织诱导率较叶片和根段高.激素的筛选试验表明,MS＋2mg/L 6-BA＋0.2 mg/L NAA对愈伤组织诱导效果良好.对不同萱草品种的相同外植体进行愈伤组织诱导实验,发现其诱导效率也不同：萱草品种H.hybrida Stella D＇Oro生长愈伤组织数量最多,80%以上的茎尖诱导出愈伤组织并再生出芽;H.hybrida Pink Charm在愈伤组织诱导培养基上,约50%的无菌苗获得愈伤组织;H.hybrida Bayley Hay在愈伤组织诱导培养基上,经过1个月的诱导,即可产生愈伤组织,其诱导成功率为30%～40%;H.hybrida Frans Hal诱导产生愈伤组织的频率较低,为20%～30%.     

A new species of Hedysarum (Fabaceae) in Iran and other new Hedysarum records

Hedysarum al-shehbazii , a new species endemic to Iran, is described and illustrated. This species belongs to Hedysarum section Multicaulia . It is confined to the western part of Iran (Kermanshah Province), and is known from a single population close to the Iraq frontier, although possibly also growing in the adjoining eastern part of Iraq. The conservation status of this species is 'vulnerable' according to World Conservation Union (IUCN) criteria. In addition, H. varium and H. syricum are reported as new records from a single gathering close to the Turkish frontier. Moreover, H. kotschyi and H. pogonocarpum are transferred from Hedysarum section Crinifera to Hedysarum section Multicaulia .  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 155 , 505–512.     

Chemotaxonomy studies on the genus Hedysarum

In combination with phytochemical results, the pilot chemotaxonomy study on genus Hedysarum by using HPLC methods revealed differences between section Fruticosa and the three other sections Multicaulia, Obscura and Subacaulia, but there was a closer genetic relationship with Multicaulia and Subacaulia. Isoflavonoids and pterocarpans were proved to be the common constituents of genus Hedysarum, whereas pterocarpans, benzofurans, and coumestans were the characteristic constituents of section Fruticosa, and chalcones were the chemical markers of section Multicaulia and section Subacaulia. The present finding is consistent with the classical morphological classification of genus Hedysarum, and provides supporting evidences for dividing Hedysarum into two subgenera, i.e. subgenus Hedysara and subgenus Ruticosa.     

Variation of plastid and mitochondrial DNAs in the genus Hedysarum

Summary Plastid and mitochondrial DNAs from Hedysarum species of the western Mediterranean basin, H. spinosissimum ssp eu-spinosissimum, H. spinosissimum ssp capitatum, H. carnosum, H. coronarium and H. flexuosum, were compared by restriction endonuclease fragment analysis. ctDNA fragment patterns for ssp eu-spinosissimum and ssp capitatum were indistinguishable in different enzyme digests. An identical ctDNA variation was found in Hpa II digests with two Sardinian populations of ssp capitatum. Each of the two subspecies was characterized by specific mt DNA patterns with Pst I, Bam HI, Sma I and EcoRI. No variation was detected in populations of different geographical origins for a given subspecies. H. carnosum, H. coronarium and H. flexuosum generated specific ct and mt DNA patterns. Comparison of mitochondrial fragments indicated: — a strong homology between the two subspecies, — a closer homology among the three other diploids, each being closer to the other two than to H. spinosissimum subspecies — as was also the case for the plastid genomes.     

Diversity of Rhizobia isolated from various Hedysarum species

Cultural and physiological properties, serology, plasmid profiles and infective traits were determined for 23 strains of rhizobia isolated from various Hedysarum species: H. coronarium (common name: sulla) (16), H. carnosum (1), H. alpinum (3), H. mackenzii (2) and H. pallens (1) from Portugal, Spain, Tunisia, Alaska and Israel. Strains isolated from H. alpinum, H. mackenzii and H. pallens have slow growth rates on yeast-extract mannitol medium and were unable to nodulate H. coronarium plants, whereas the latter were effectively nodulated by all sixteen fast growing strains from sulla. Regardless of the country of origin all H. coronarium strains fell into one serogroup and were not serologically related with strains of other Hedysarum species. The RAPD (random amplified polymorphic DNA) fingerprinting method which was carried out on five H. coronarium and three H. alpinum strains allowed distinction to be made among serologically related rhizobia. No particular plasmid profile pattern was observed in relation to the host or geographical origin of the strains.     

Gamma proteobacteria can nodulate legumes of the genus Hedysarum

The bacteria hosted in the root nodules of the three Mediterranean wild legume species Hedysarum carnosum, Hedysarum spinosissimum subsp. capitatum, and Hedysarum pallidum, growing in native stands in different habitats in Algeria were isolated. Bacteria were recovered on yeast-mannitol-agar or on minimal media from a total of 52 nodules. Isolates were analyzed by Amplified Ribosomal DNA Restriction Analysis (ARDRA) using the enzyme CfoI, and further sorted by RAPD fingerprinting. A total of ten different types were found and their amplified 16S rDNA was sequenced and compared to databases. The BLAST alignment indicates that all the species whose sequences share 98 to 100% identity to the bacteria found in these nodules belong to the class Gammaproteobacteria and include Pantoea agglomerans, Enterobacter kobei, Enterobacter cloacae, Leclercia adecarboxylata, Escherichia vulneris, and Pseudomonas sp. No evidence of any rhizobial-like sequence was found even upon amplifying from the bulk of microbial cells obtained from the squashed nodules, suggesting that the exclusive occupants of the nodules formed by the three plants tested are members of the orders Enterobacteriales or Pseudomonadales. This is the first report of Gammaproteobacteria associated with legume nodules. Despite the presence of the related crop plant Hedysarum coronarium, specifically nodulated by Rhizobium sullae, these three Hedysarum species demonstrate to have undergone a separate path in terms of endophytic interactions with bacteria. An hypothesis to account for differences between the symbiotic relationships engaged by man-managed legumes, and those found in plants whose ecology is independent from human action, is discussed.     

岩黄耆属系统分类研究进展

回顾了自Fedtschenko以来在岩黄耆属分类、区系地理和系统发育方面所取得的成就,根据目前的研究现状,提出了岩黄耆属今后研究的重点和方向。     

花棒茎流对降雨的响应

干旱半干旱区植物生理过程的水分响应依赖于降雨强度和频率,研究典型沙生植物对降雨的响应有助于预测未来气候条件下荒漠生态系统的结构和功能变化.2012和2013年花棒生长季,在宁夏盐池采用包裹式茎流仪对花棒茎流进行连续观测,分析茎流在晴天和雨天的变化特征及其对不同降雨事件的响应.结果表明: 雨天的花棒日茎流量低于晴天.晴天,茎流日变化呈“几”字型宽峰曲线,与太阳辐射和相对湿度呈正相关;雨天,茎流日变化呈多峰曲线或者一直处于极低状态,与太阳辐射和空气温度呈正相关.降雨不仅可以通过影响当天太阳辐射、空气温度、饱和蒸汽压差和相对湿度影响花棒茎流通量,还通过调控土壤含水量影响降雨后的茎流通量.降雨量<20 mm时,降雨前后茎流通量差异不显著;降雨量>20 mm时,降雨后的茎流通量比降雨前有显著提高.高土壤含水量不仅能够提高茎流通量,并且能够提高茎流通量对太阳辐射、饱和水汽压差和空气温度的响应敏感性.