湿地松成熟合子胚直接器官发生及植株再生

以湿地松成熟胚为外植体诱导不定芽发生,初步建立植株再生体系.先用含不同浓度6-BA的液体培养基处理湿地松成熟胚12～36 h,吸干后转移到无激素的培养基上培养.6周后,经60mg·L-1 6-BA液体培养基预处理12 h的胚不定芽诱导率最高达69%,预处理24 h平均每个外植体产芽数达到最高(9～12个),但芽体较小,在继代培养基中伸长较慢;经30 mg·L-1 6-BA液体培养基预处理的胚不定芽诱导频率较低,仅25%～38%,但芽体健壮,在继代培养基中伸长较快;6-BA浓度大于80 mg·L-1时不利于不定芽分化.不定根诱导的研究结果表明,NAA对不定芽生根具有促进作用,在改良1/2GD NAA0.05mg·L-1培养基中培养4周后,生根率达50%,移栽成活率为60%左右.     

沙松成熟胚不定芽诱导研究

以沙松成熟胚为外植体进行不定芽的诱导研究,结果表明:初代培养中沙松成熟胚不定芽诱导最佳培养基组合为改良DCR+2.0 mg·L-16-BA,诱导率可达到63.16%;继代培养中最佳培养基为无添加激素的1/2SH培养基,培养30 d不定芽平均伸长0.7 cm;添加0.1 mg·L-1的活性炭对沙松不定芽的伸长生长最为适宜。     

离体条件下西黄松成熟合子胚不定芽的诱导及植株再生

以西黄松成熟胚为外植体诱导不定芽,在GD 9.85～19.70 μmol·L'-1 6-BA 0.0～14.42 μmol·L-1 NAA上不定芽诱导率最高达65.8%,平均增殖率为7,最大增殖率达10;不定芽形成有2种途径,即子叶直接形成不定芽和子叶组织再分化形成不定芽;NAA不利于外植体不定芽的诱导;不定芽的生长和扩繁采用不加生长调节剂的1/2 GD和1/2 SH培养基;培养基中加入适量的活性炭有利于不定芽和根的生长.不定嫩梢在1/2 GD和1/2 SH附加不同浓度NAA和GA,3的培养基上进行生根诱导,试验结果表明:NAA对不定根的形成起主要作用,在1/2 GD 28.84 μmol·L'-1 NAA 4.17 μmol·L'-1 GA,3培养基中不定梢的生根率为16.7%.在离体培养条件下,以西黄松成熟胚为外植体获得了再生植株.     

葡萄不定芽离体诱导再生植株的研究

进行了紫苑、魏可和砧木 99R几个葡萄品种不定芽离体诱导再生植株的研究。实验通过对其叶片、叶柄、茎段外植体的诱导再分化 ,以器官发生途径实现植株再生。结果表明 :不同品种间存在差异 :(1)紫苑不定芽诱导再生效果最好 ,其中用IBA与TDZ组合诱导最好 ,叶柄在MS +IBA0 .2 0mg/L +TDZ0 .75mg/L培养基中再生率高达 4 2 .9% ;用IBA与BA组合效果也较好 ,叶柄和茎段在MS +IBA0 .0 5mg/L +BA2 .0mg/L中再生率达 30 .8%。 (2 )魏可叶柄不定芽诱导再生在MS +IBA0 .2 0mg/L +BA2 .0mg/L培养基再生率 2 0 .0 %。 (3)砧木品种 99R不定芽诱导再生率较低 ,叶片在MS +IBA0 .0 1mg/L +BA1.5mg/L培养基中再生率 2 0 .8%。(4)栽培品种比砧木易于诱导再生不定芽     

思茅松丛生芽诱导及植株再生

以思茅松成熟合子胚培育的无菌苗的带子叶顶芽为外植体,建立了思茅松组培的丛生芽诱导、伸长和生根的植株再生体系。丛生芽诱导培养基为1/2MS+2.0～3.0 mg.L-16-BA+0.05～0.1 mg.L-1NAA,其诱导率为93.3%;丛生芽伸长诱导培养基为1/2 MS+0.05 mg.L-1NAA;丛生芽小芽不定根诱导培养基为1/2MS+2.0 mg.L-1IBA,其生根率为46.67%。     

火炬松丛生芽诱导及植株再生

采用火炬松带子叶项芽为外植体建立了组织培养再生体系。结果表明,火炬松丛生芽的形成受诱导培养基中激素浓度及外植体年龄的影响较大。适合火炬松丛生芽诱导的培养基为改良GD 6-BA 4 ms／L NAA 0．02 mg/L(诱导率86．7％),截取外植体的最佳苗龄为14-21 d。已分化的丛生芽继代培养在无6-BA但附加0．5- 1．0 g/L活性炭或0．02-0．05 mg/L NAA的培养基上伸长很快。伸长的丛生芽接种在附加0．05 ms／L NAA的1／2改良GD培养基中,1个月后有12．5％产生不定根。     

樟子松成熟胚的离体培养与不定芽的形成

沙藏45d的樟子松种子,剥胚培养在5个系列17种培养基上.在6BA0.2～2.0(mg/L,单位下同)+NAA0.05～0.5以及6BA1.0+IAA0.2～0.5的激素配比范围内,可诱导胚形成不定芽.KT与NAA或IAA配合时无不定芽形成.不定芽分化部位明显受激素种类控制,6BA与NAA配合可诱导胚轴分化出不定芽,而6BA与IAA配合,则可从子叶顶端和基部诱导出不定芽。     

桔梗丛生芽的诱导及植株再生

用桔梗茎段为外植体,以MS为基本培养基,对添加不同浓度和比例的外源激素对桔梗丛生芽的诱导、增殖及植株再生的影响进行探讨。结果表明:丛生芽诱导培养基以MS+6-BA0.3mg/L+NAA0.05mg/L效果最佳;增殖培养基以MS+6-BA2.0mg/L+NAA0.5mg/L效果最佳;生根培养基以1/2MS+NAA0.2mg/L效果最佳。     

长白落叶松愈伤组织及不定芽的诱导

以长白落叶松成熟合子胚为研究对象,从外植体消毒方式及愈伤组织与不定芽诱导的适宜培养基、激素组合和配比的选取等方面着手,进行长白落叶松愈伤组织及不定芽诱导的研究。结果表明:先用4%NaClO消毒去皮种子15 min后,再用0.5%NaClO消毒胚2 min为长白落叶松成熟合子胚的最佳消毒方法;BM为愈伤组织诱导的最适培养基;当BM+2.0 mg·L^-1 TDZ时,愈伤组织诱导率最高,为89%;BM+1.5 mg·L^-1 TDZ时,不定芽诱导率最高,为80.0%。     

Callus induction and plant regeneration from mature bluegrass (Poa pratensis L.) seeds

A protocol was discussed for high efficient plant regeneration from seven bluegrass (Poa pratensis L.) cultivars via an indirect callus induction and somatic embryogenesis method. Mature seeds were used as explants for callus initiation. Callus induction and proliferation efficiencies were investigated on NB, modified MS (MMS) and MS media, supplemented with 2.0 mg·L-1 2,4-dichlorophenoxyacetic acid (2,4-D). The MMS medium performed best. Based on the MMS medium, direct and indirect callus induction effects of bluegrass from mature seeds were compared at the range of 1-5 mg·L-1 2,4-D contained in the medium. Under the direct callus induction method, the most suitable 2,4-D concentrations varied among cultivars. Under the indirect callus induction method, a significantly high callus induction frequency (93.33%-98.33%) was obtained and there were barely any statistically significant differences among the tested genetically diverse cultivars. Somatic embryos were promoted on the MMS medium supplemented with 3 mg·L-1 2,4-D, 0.1 mg·L-1 kinetin and 0.8 mg·L-1 CuSO4. Embryogenetic calli developed into plantlets on the MMS medium containing different concentrations of thidiazuron (TDZ), and the differentiation frequencies varied in the range from 20.15% to 77.65%. The 0.25 mg·L-1 TDZ was generally the most suitable concentration for the tested cultivars.     

Micropropagation of mature Calabrian pine (Pinus brutia Ten.) from fascicular buds

Dormant meristems of fascicles explanted from 10-year-old, field-grown trees of Pinus brutia Ten. were cultured in vitro. Browning of cultured fascicles was reduced by including 150 mg l(-1) sodium diethyldithiocarbamate (SDD) in a cytokinin-containing medium. The stage of development of fascicles when placed in culture affected both shoot-bud production and the degree of browning. Only fascicles at an advanced stage of development had a high rate of shoot-bud production. Fascicles cultured for 6 weeks in initiation medium containing 150 mg l(-1) SDD and then for 4 weeks in initiation medium containing 1 mg l(-1) insoluble polyvinylpolypyrrolidone showed the highest rate (23%) of shoot-bud development and the lowest rate (15%) of browning. Elongation of activated shoot buds was considerably enhanced by reducing the concentration of cytokinin in the culture medium. Only shoots >/= 20 mm in height were capable of producing further crops of buds and shoots. When treated with a combination of auxin and cytokinin, only 16% of the elongated shoots produced roots.     

Somatic embryo production and plant regeneration of Japanese black pine (Pinus thunbergii)

Somatic embryogenesis in Pinus thunbergii was initiated from megagametophytes containing immature zygotic embryos. Embryogenic cultures were maintained and proliferated in medium supplemented with 2,4-dichlorophenoxyacetic acid and 6-benzylaminopurine. High maturation frequencies of somatic embryos were obtained on maturation media containing maltose, activated charcoal, abscisic acid, and polyethylene glycol as osmotic agent. The best result among the cell lines tested was achieved with the cell line T-205-3. More than 900 somatic embryos per petri dish, on average, were obtained after about 8 weeks of culture on maturation medium. Sixty percent of somatic embryos tested germinated after transfer to plant growth regulator-free medium and then 85% of them converted into plantlets.     

In vitro regeneration of plantlets from mature embryos of Pinus ayacahuite

A plantlet regeneration protocol was developed for Pinus ayacahuite var. ayacahuite (Ehrenb.). Embryos from mature seeds from ten provenances were cultured in a 16-h photoperiod for 3 days on a medium containing 30 mM sucrose and 0.7% agar. Cotyledons from these embryos were subcultured onto MCM medium (Bornman 1983) supplemented with 50 micro M N(6)-benzyladenine and 90 mM sucrose for 2 weeks. Bud development and shoot elongation were maximized by subculturing the explants on half strength AE medium (von Arnold and Ericksson 1981), supplemented with 60 mM sucrose and 0.05% activated charcoal every 30 days. Seed source had a significant effect on the responses of the embryos to the bud induction protocol. For the provenance with the best response to bud induction, about 79% of the cultured cotyledons formed buds, and each cotyledon formed a mean of 9.1 buds, so that about 70 shoots could be induced from each seed. The best rooting response (40% rooting) was obtained by treating the shoots for 8 h with 100 micro M naphthalene acetic acid.     

Adventitious micropropagation of mature Larix decidua using dormant versus flushed axillary vegetative buds

Tissues of winter-dormant buds were collected from mature Larix decidua, and used for adventitious shoot organogenesis. Tissues of dormant buds merely died on the cytokinin-supplemented, bud-initiation medium. In contrast, buds allowed to flush under greenhouse conditions subsequently yielded approximately two adventitious shoots per bud explant tissue. These shoots elongated normally and several rooted spontaneously. Microbial contamination of in vitro cultures was negligible using explants from buds orgininally collected in a dormant state.     

马尾松成熟胚愈伤组织的增长研究

基本培养基和生长调节剂对马尾松成熟胚愈伤组织增长的影响表明:马尾松成熟胚愈伤组织的增长适应范围较广,对DCR,LV,WV5三种基本培养基以及2,4-D和BA试验3种浓度要求不严格,9种试验组合愈伤组织均能保持旺盛增长.采用DCR+2,4-D0.5 mg/L+BA0.5 mg/L培养基,马尾松成熟胚愈伤组织经多次继代均能保持旺盛增长.     

大强度抚育对油松人工林天然更新的影响

以油松人工林为研究对象,在大强度抚育条件下,通过林分层次结构、各层次林木胸径结构、树高结构及其林木分布格局等指标研究林下天然更新状况,结果表明:油松人工林在22a、32a时分别进行株数强度50%和40%的下层抚育,后经20a天然更新(林分年龄52a),林分形成明显层次结构,分为主林层、演替层及更新层,整个林分林木胸径、树高结构均呈多峰分布,其中主林层、演替层林木胸径和树高结构均呈单峰山状分布,更新层林木胸径和树高结构呈多峰分布,各林层平均胸径分别为23.2cm、12.6cm和3.1cm,平均树高分别为18.4m、14.5m和2.8m,而对照标准地胸径、树高结构均呈单峰分布,平均胸径、树高分别为18.6cm及17.9m;主林层、演替层各层林木空间分布呈均匀分布,密度分别为840株/hm~2和1 125株/hm~2,更新层林木空间分布呈聚集分布,密度为675株/hm~2,对照样地林木空间分布偏向均匀分布,密度为1 605株/hm~2。     

朝阳地区油松人工林天然更新的主要类型

采用标准地调查方法对朝阳地区油松人工林天然更新进行了研究,将其归纳为疏林林下更新、林缘更新、侵蚀沟更新、林隙更新和动物传播种子更新5种类型。不同坡向疏林地油松天然更新幼树株数差异明显;侵蚀沟内油松天然更新明显优于正常坡面;阴坡林隙更新良好,阳坡林隙基本不能进行天然更新;油松林缘更新幼树主要分布于距林缘20 m以内;动物传播种子天然更新多以散生天然油松幼树形式存在。     

The effects of microhabitat,plant litter,and seed burial on the regeneration of Quercus wutaishanica and Pinus tabulaeformis

The effects of microhabitat (shrubs and herbs), plant litter, and seed burial on the regeneration of Liaodong oak (Quercus wutaishanica Mayr) and Chinese pine (Pinus tabulaeformis Carr.) were studied in three typical stands (Liaodong oak forest, Chinese pine plantation, and grassland) in the Loess Plateau, China. We monitored the establishment and growth of seedlings of these two woody species in sown experimental plots, in which shrubs and herbs, plant litter, and seed burial were manipulated. In the grassland, shrubs and herbs facilitated Liaodong oak establishment, with no effect on the establishment of Chinese pine. In the two forest stands, shrubs and herbs primarily had an inhibition effect on the establishment of these trees. The effects of plant litter were facilitation or inhibition, depending on the target species and the habitat. Seed burial had a positive effect on seedling establishment. In all three habitats, shrubs and herbs had inhibition effects on seedling growth of both tree species. Plant litter and seed burial did not influence seedling growth in either species. Liaodong oak and Chinese pine use different regeneration strategies during early stages of succession and similar strategies during late stages of succession.     

海拔对油松天然更新和胸径生长的影响

通过比较河北省木兰围场国有林场管理局森林经营区不同海拔高度油松天然更新及生长情况,研究不同海拔高度对油松天然更新和胸径生长的影响,结果表明:不同海拔高度油松天然更新能力强弱依次为951~1 150m750~950m1 151~1 350m1 351~1 550m1 551m以上;而不同海拔高度对天然更新油松的胸径平均年生长量的影响为,0~60a油松在海拔951~1 350m时胸径生长最快,而在750~950m和1 551m以上的海拔区间生长较慢,61~90a油松在7 50~1 550m的海拔高度,胸径平均生长量没有差异,而在1 551m以上,生长量明显下降。