ZT、ABA等内源物质与杉木树龄及其组培复壮的关系

对不同树龄的杉木嫩梢及其培养体中ABA、ZT和单宁含量的变化作了分析测定。结果表明:在不同季节ABA和单宁的含量均和树龄呈正相关。三种年龄杉木的嫩梢中ABA含量的年变化趋势基本相同,均以抽梢旺季较低,盛夏季节较高。根据ABA水平,组培材料的采集应在春梢生长旺季进行。 采自2、10年生母本的外植体材料,经初代培养后,ZT含量均有明显上升。但在2年生母本培养体中尤为明显。与此同时ABA含量却大幅度下降。经4次继代培养后两种材料中ZT含量均有所下降,且差异缩小。ABA含量却出现回升。它们的消长与嫩梢增殖能力有关。     

ZT、ABA等内源物质与杉木树龄及其组培复壮的关系

对不同树龄的杉木嫩梢及其培养体中ABA、ZT和单宁含量的变化作了分析测定。结果表明:在不同季节ABA和单宁的含量均和树龄呈正相关。三种年龄杉木的嫩梢中ABA含量的年变化趋势基本相同,均以抽梢旺季较低,盛夏季节较高。根据ABA水平,组培材料的采集应在春梢生长旺季进行。采自2、10年生母本的外植体材料,经初代培养后,ZT含量均有明显上升。但在2年生母本培养体中尤为明显。与此同时ABA含量却大幅度下降。经4次继代培养后两种材料中ZT含量均有所下降,且差异缩小。ABA含量却出现回升。它们的消长与嫩梢增殖能力有关。     

西蒙得木组织培养繁殖技术的研究

通过对西蒙得木〔Simmondsia chinensis(Link)〕组织培养大批量繁殖技术的研究,探索基本培养基、生长调节物质及蔗糖含量等对嫩梢增殖及生根的影响,结果表明:采用春季生长的1年生实生苗以及6年生高产的优株茎节作外植体,培养于含有ZT 1～3 mg/L或BA 1～3mg/L和NAA 0.01～0.1 mg/L的MS培养基中,经30～40天,几乎所有腋芽均能长成嫩梢,切取长达4～6 cm的嫩梢,培养于含有NAA的1/2MS培养基中,经1周暗培养,1个月后生根率达93％,小植株移栽于含砂土的基质中,保持湿润,获得成功。用幼苗及优株作外植体的培养效果无显著差异,说明此法不受遗传型的限制。     

台湾的泡桐丛枝病

由类支原体(mycoPlasma—likeorganism(引起丛枝病是台湾泡桐)Paulownia taiwaniana)一种最严重的致命病害,也是台湾发展泡桐的限制因素。台湾泡桐的丛枝病是1974年发现的,传播迅速。感染的树木长出很多次生枝和三次嫩梢、叶少、枝和嫩梢黄绿色,当季顶枯,次年树木停止生长。取自病株的根插条大多有丛枝病症状。台湾泡桐和白桐     

黄榆组织培养再生体系建立

以黄榆枝条水培萌发的茎尖与茎段为外植体进行组织培养研究,建立植株再生体系,结果表明:初代培养以WPM培养基最佳,诱导率可达77.16%,外植体最佳灭菌时间为6 min,最佳细胞分裂素为6-BA,以1.0 mg·L~(-1)质量浓度诱导效果最佳,2 a生母树采集的外植体诱导率最高;继代培养以WPM+6-BA2.0 mg·L~(-1)+NAA0.3 mg·L~(-1)效果最佳,平均增殖芽数达到4.1个;生根培养以1/2MS+NAA0.5 mg·L~(-1)最佳,20 d后试管苗生根率可达83.33%,平均生根数为3.2个。     

糖和激素对香花槐微体快繁的的影响

以香花槐的幼茎为材料建立无性系，研究了蔗糖、BA、NAA和IBA等物质对香花槐嫩梢增殖倍数、嫩梢长度以及根诱导的影响。试验结果表明，增殖培养适宜蔗糖浓度为30g／L，BA浓度为0．5mg／L，N从浓度为0．05mg/L。根诱导可用NAA或IBA，但以NAA为最好，适宜的浓度为O．5～1．0mg／L。     

有机物和激素对四倍体刺槐微体快繁的影响

研究了水解乳蛋白(LH),蔗糖,BA,NAA和IBA等物质对四倍体刺槐嫩梢增殖倍数、嫩梢长度以及根诱导的影响。结果表明,增殖时的适宜BA浓度为0．5mg／L,NAA浓度为0．05mg／L,蔗糖浓度为30g／L,增加LH有利于提高增殖倍数。根诱导用NAA为好,适宜的浓度为0．5～1．0mg／L。     

平榛离体培养技术的研究

对平榛外植体不同取材时期和外植体种类对初代培养的影响及增殖培养阶段不同激素对增殖生长的影响进行研究.结果表明:外植体种类与取材时间是平榛离体培养的关键,最佳外植体为休眠过后室内萌发的嫩梢顶芽,其污染率低,萌芽率可达83.33%;适宜平榛离体培养的基本培养基为DKW培养基;芽分化阶段较好的培养基为DKW+TDZ 1.0mg/L+IBA 0.01mg/L+GA0.2mg/L;继代增殖培养阶段,细胞分裂素TDZ和生长素IBA的组合最有利于芽的增殖生长,其最适浓度分别为0.5mg/L和0.1mg/L,增殖倍数为3.2.     

针叶树的快速无性繁殖

对于影响针叶树种插条生根潜力的因素作了研究,目的在于改进快速无性繁殖的方法。在遗传限度范围内,根的再生能力在相当程度上取决于生根基质(按:例如砂、土壤等),对质量、扦插的日期、材料植物的年龄和生理状况、插条材料的年龄和它在植物体上的位置以及化学处理。硬枝插条的效果最好,因为它具有较高含量的植物生长素、碳水化合物和形态学上的根原始细胞。用它要比取自正在生长的嫩梢作插条,能提高生长速度2.5～5倍。     

迷迭香工厂化育苗技术

用迷迭香小苗枝条为外植体进行组织培养，用组培苗嫩梢作为插穗进行扦插育苗试验。结果表明：芽增殖以MS＋6BA0.5mg/L NAA0.01mg/L 蔗糖30g/L培养基的增殖率达1.4倍；不定根诱导以1／3MS＋IBA0.5mg/L 蔗糖20g/L的培养基效果好，生根率达100％；以组培苗嫩梢扦插，生根率达98％以上。利用芽增殖培养→生根炼苗培养→移栽上盆→扦插→出圃这一流程生产苗木，成本低、苗木质量优、繁殖速度快，可在生产上推广应用。     

Micropropagation of red sanders (Pterocarpus santalinus L.) using mature nodal explants

In vitro clonal multiplication of Pterocarpus santalinus L. was achieved using mature nodal explants of a 10-year-old elite quality tree. Combinations of serial transfer technique and incorporation of antioxidants (250 mg/l L-ascorbic acid and 50 mg/l citric acid) into the culture medium helped to minimize medium browning and improve explant survival during shoot sprouting. About 70% of explants were sprouted on Murashige and Skoog (MS) liquid medium containing 4.4 μM 6-benzyladenine (BA). The explant harvest period also influenced the bud break and shoot sprouting in nodal explants. The combination of 4.4 μM BA and 2.2 μM thidiazuron (TDZ) was found to be the most suitable growth regulator for obtaining the highest percentage of nodal segment sprouting (74%–75%), the number of secondary shoots per primary shoot (two or three), the shoot length (5–6 cm), the number of new nodal segments generated per active explant (four or five), and the multiplication coefficient (3.5) within 6 weeks. Repeated subculturing of nodal explants obtained from shoot cultures enabled continuous production of healthy axillary shoots. At the end of the sixth passage, about 90% of nodal explants produced five or six healthy green shoots, each being about 6.6 cm long with six or seven nodes. Multiplication coefficient was also increased from the first subculture (5.4) to the sixth subculture (8.3). The best rooting response was achieved on solidified half-strength MS medium supplemented with 4.9 μM indole-3-butyric acid (IBA). About 70% of the micropropagated plantlets were established successfully in 20-cm pots containing a mixture of soil and farmyard manure (4 : 1 ratio) and formed new leaflets.     

Rapid Micropropagation of Edible Bamboo Dendrocalamus asper

Abstract

Micropropagation protocols for Dendrocalamus asper using nodal shoots and seeds culture are described. Multiple shoots were induced through forced axillary branching. Ninety-five percent of the nodal shoot explants taken from juvenile primary and lateral branches, produced multiple shoots through axillary buds activation within 2 to 8 weeks on Murashige & Skoog's (MS) medium supplemented with 0.1-15 mg/l benzyladenine (BA). The cultured seeds also produced multiple shoots (1-20) within 6 weeks on this medium. The multiple shoot differentiation was influenced by the concentration of BA in the medium. The in vitro generated shoots were excised and subculture on MS + 3.0 mg/l BAP for further shoot multiplication. Fifteen to 20 fold rate of shoot multiplication was achieved by regular subculturing. These shoots were multiplied for more than 3 years without loss of vigor. Ninety-five percent of the shoots were rooted, when propagules (each consisting of cluster of 3 shoots) were transferred on to MS medium with 3.0 mg/l NAA or 10 mg/l indole-3-butyric acid (IBA).

To date, 18,000 plants (through axillary bud initiated from nodal ex-plants) and 6,000 plants from seed culture have been hardened and acclimatized. 12,000 plants have been field transferred.     

Photosynthesis of oak leaves under water stress: maintenance of high photochemical efficiency of photosystem II and occurrence of non-uniform CO(2) assimilation

Shoot cultures of Quercus rubra (L.) were established from both juvenile and adult plant material. Initial explants from epicormic shoots formed on the basal zone of the trunks had a greater capacity for in vitro establishment than explants from crown branches. The growth of vigorous axillary shoots was obtained by culturing decapitated shoots horizontally on Woody Plant Medium supplemented with 0.2 mg l(-1) of 6-benzylaminopurine. After 3 weeks of culture the shoots were transferred to fresh medium for two more weeks, giving a 5-week multiplication cycle. Efficient shoot production was achieved by combining three treatments favoring the growth of lateral buds: excision of the apex, horizontal culture and cytokinin treatment. The addition of indoleacetic acid or indolebutyric acid to the multiplication medium did not improve shoot proliferation rates, and naphthaleneacetic acid was detrimental. Recycling the same explant for several successive subcultures improved the efficiency of the propagation procedure. Using the optimal multiplication procedures, nine clones (six of juvenile origin and three from adult trees) were tested in vitro and it was found that genotype and age affected performance.     

Factors affecting in vitro propagation of Quercus robur L

Explants from five clones of Quercus robur (three of juvenile origin and two from adult trees) were cultured on Gresshoff and Doy medium supplemented with 0.2 mg l(-1) 6-benzylaminopurine. Shoot proliferation from apical and nodal segments was influenced by both clone and type of explant. To increase the efficiency of the propagation procedure, donor shoots (20-25 mm in length and with 2 mm removed from the tip) were recultured at 4-week intervals, and the newly formed shoots harvested before each transfer. Under this regime, the multiplication coefficient (proportion of explants forming axillary shoots multiplied by the mean number of new 8-mm stem segments per explant) was greatest for the second crop and declined sharply by the fourth or fifth crop, in three of the four clones tested. Successive additions of fresh liquid medium to old cultures was much less effective than transfer to fresh medium in promoting axillary shoot production. Elongation of shoots before rooting was increased significantly (P < 0.05) in one of two clones tested by transfer to a medium containing either 0.1 or 1.0 mg l(-1) of zeatin. Addition of fresh liquid medium containing zeatin to old cultures failed to improve shoot elongation or axillary shoot production. However, treatment for 15 days with liquid medium containing 0.1 or 1.0 mg l(-1) indol-3-yl-acetic acid increased subsequent rooting.     

黄金香柳的组织培养与快速繁殖

文章报道黄金香柳的组织培养和快速繁殖试验。结果表明：以黄金香柳嫩茎作外植体进行培养,不定芽诱导率高,经连续3次培养不定芽增殖倍数可达7.9～10.7。适宜黄金香柳丛芽快速增殖的培养基配方为MS＋6-BA 0.5 mg/L＋NAA 0.01 mg/L＋蔗糖30 g/L,一次继代培养时,平均每瓶无菌材料可提供45.5个枝芽（≥1 cm）用于转接生根。诱导植株生根的最佳培养基配方为MS＋IBA 1.0～1.5 mg/L＋蔗糖15 g/L,适宜的培养时间为21～25 d,生根率可高达96%以上。移植的试管植株90%以上存活。     

Regeneration and multiplication of Albizia procera Benth. through organogenesis

Vegetative propagation techniques are recognized as indispensable tools for mass multiplication of important multipurpose trees adopted in different agroforestry systems. Albizia procera, one among important species, is difficult to propagate commercially either by stem / root cuttings or layering. A study was undertaken to develop procedure for its in vitro regeneration through organogenesis. Explants collected from 15±2 yr-old mature plus trees and from 15 days old juvenile seedlings were regenerated with exogenous application of different hormones. Epicotyl and hypocotyl explants excised from juvenile seedlings showed higher callusing than axillary bud and shoot tip explants derived from mature trees. Benzylaminopurine (BA) at 3 μg/l was most effective, which induced hundred percent callusing in epicotyl and hypocotyl explants in 1/2 Murashige and Skoog (MS) medium. Callus originated from axillary buds and apical shoot tips of mature trees failed to form organs, however callus derived from epicotyl and hypocotyl explants proliferated and formed de novo shoots and leaflets. A concentration of 3 μg/l of BA was found effective for shoot proliferation. Shoots grew vigorously in 2 μg/l gibberellic acid (GA₃) treatment and rooted in 1/2 MS medium supplemented with indole-3-butyric acid (IBA) and indole-3-acetic acid (IAA). Rooting was most successful on medium supplemented with 6 μg/l IBA alone on which 93.3% of the shoots formed roots. Sand or vermiculite supplemented with 4 ml of yoshida solution proved as best hardening media, which recorded 70-80% survival of plantlets. One year old tissue culture raised plants had comparatively more height, collar diameter, biomass, and root shoot ratio than plants raised from cuttings and seeds of the same age. The procedures enumerated provide a basis for the development of in vitro techniques for rapid multiplication of A. procera. This revised version was published online in June 2006 with corrections to the Cover Date.     

In vitro morphogenetic competence of basal sprouts and crown branches of mature chestnut

Basal shoots of five clones of mature chestnut tree (Castanea sativa Mill. and C. sativa x C. crenata Siebold & Zucc.) had a greater capacity for in vitro establishment, multiplication and rooting than crown branches of the same trees. Cultures from basal shoots were more responsive than crown-derived cultures in terms of in vitro reactivity (proportion of the explants with shoot development), the mean number of shoots formed per explant, the length of the tallest shoot in each culture, and the multiplication coefficient (defined as the product of the reactivity and the mean number of shoots per explant). Multiplication coefficients were greatest between subcultures 6 and 12, but subculturing failed to increase the rooting potential of shoots of crown origin. Multiplication and rooting rates were also determined for clones derived from seeds of mature trees. Genotype influenced the in vitro performance of clones of both adult and seedling origins.     

In vitro regeneration of Salix nigra from adventitious shoots

Black willow (Salix nigra Marsh.) is the largest and only commercially important willow species in North America. It is a candidate for phytoremediation of polluted soils because it is fast-growing and thrives on floodplains throughout eastern USA. Our objective was to develop a protocol for the in vitro regeneration of black willow plants that could serve as target material for gene transformation. Unexpanded inflorescence explants were excised from dormant buds collected from three source trees and cultured on woody plant medium (WPM) supplemented with one of: (1) 0.1 mg l(-1) thidiazuron (TDZ); (2) 0.5 mg l(-1) 6-benzoaminopurine (BAP); or (3) 1 mg l(-1) BAP. All plant growth regulator (PGR) treatments induced direct adventitious bud formation from the genotypes. The percentage of explants producing buds ranged from 20 to 92%, depending on genotype and treatment. Although most of the TDZ-treated inflorescences produced buds, these buds failed to elongate into shoots. Buds on explants treated with BAP elongated into shoots that were easily rooted in vitro and further established in potting mix in high humidity. The PGR treatments significantly affected shoot regeneration frequency (P < 0.01). The highest shoot regeneration frequency (36%) was achieved with Genotype 3 cultured on 0.5 mg l(-1) BAP. Mean number of shoots per explant varied from one to five. The ability of black willow inflorescences to produce adventitious shoots makes them potential targets for Agrobacterium-mediated transformation with heavy-metal-resistant genes for phytoremediation.