竹节海棠叶外植体脱分化启动的细胞学观察

竹节海棠叶外植体接种于MS+6-BA1ppm+NAA0.1ppm培养基上。外植体脱分化启动过程中,表皮及叶肉细胞主要以劈裂的无丝分裂方式进行分裂:最初核延伸为纺锤形,核仁大而明显,使整个核的轮廓呈“眼”状;随着核的中部出现裂缝,核断开成为两部分,稍后,由原来的母细胞形成两个子细胞。由于核分裂前向细胞中央移动的距离及断裂时断裂面的不同,从而造成细胞团内细胞大小悬殊及分裂面严重混乱的不等分裂现象。文中对栅栏组织细胞脱分化启动后重复进行无丝分裂形成梯状细胞团的现象也进行了讨论。     

Organogenesis of Lear Explants of Momordica grosvenori Swingle In Vitro

Leaves of Momordica grosvenori Swingle were used as experimatal material. Plantlets were obtained on MS medium supplemented with 6-BA 1 ppm and IBA 0.5 ppm. Histocytological observations on adventitious bud formation were carried out. After 1 week in culture, mesophyll cells obviously enlarged, cell divisions began in the mesophyll cells near the cut ends of explants, and meristemoids which consisted of small dark stained cells without chloroplasts were produced. Then meristemoids continued to proliferate and redifferentiated into many leaf-shaped bodies. Three weeks after cultivation, adiventitious buds were produced from meristemoids at surface layer of leaf-shaped body. The stem of plantlet was cut off when it reached 2 cm in height, and then was transferred onto MS basic medium supplemented with NAA 0.25–0.5 ppm for rooting. About 10 days after cultivation, vigorous root system was produced from the cut end of plantlets. It is possible that this technique of obtaining whole plants by leaf explant culture provides a method for the multiplication of the good individual plants of M. grosvenori.     

云南秋海棠属叶表皮及毛被的扫描电镜观察

首次报道滇产秋海棠属46种3变种叶表皮及毛被的扫描电镜特征。研究表明所有种的特征组合均有明显区别,因而这些微形态特征可作为分种和变种的依据。在每个组内难以找到一致的特征,因而在组的划分上意义不大,但秋海棠组内毛被和表皮特征的分化却为探讨一些组间的关系提供了某些线索。另外,通过探讨各组内毛被的发生和生态环境的关系,似可看出侧膜组应为较原始的类型,从而推断各组间的关系。     

中国秋海棠属植物的叶表皮特征及其分类学意义

在光学显微镜下,对中国秋海棠属(Begonia)植物7组52种2变种的叶表皮进行观察。结果表明秋海棠属植物叶表皮形态在属内组间具有较大的相似性,表皮细胞为多边形或近多边形,垂周壁平直或弓形,大多数种类表皮细胞内具有晶体,气孔器仅分布于下表皮,且以不等型为主。叶表皮综合特征,例如表皮细胞形状,表皮毛类型,表皮细胞内晶体的类型和形态,气孔器形态以及与一些种类独有特征的组合,在种间,尤其在近缘种之间具有明显的差异。     

In vitro Organogenesis in Explants from Different Cultivars of Begonia X hiemalis

Petiole explants from 17 cultivars of Begonia X hiemalis were grown on a basal agar medium with different combinations of NAA and BA as well as on media lacking microelements or vitamins. The stock plants were kept either under short days (7–8 h of light perday) at 15°C or under long days (15–16 h of light) at 18–21°C. The day length during the in vitro culture was 20 h of light and the temperature 21°C. Explants from short-day treated stock plants did not show any differentiation. In explants from long-day treated stock plants, the percentage of explants with shoot, root and with both shoot and root initiation were recorded after 55 days. Explants forming both shoots and roots were transferred to soil, and plantlet formation was observed after another 55 days. The percentage of explants with organ and plantlet formation differed between cultivars. With increasing NAA and decreasing BA concentrations, the percentage of explants forming only roots increased, whereas the percentage of explants with only shoots decreased. Plantlet formation was most frequent in explants from NAA: BA ratios of 2: 1 and 10: 1, and a variation was found between different cultivars. When the vitamin fraction was not added to the medium, this did not influence formation of shoots, roots and plantlets. When the microelements were omitted. shoots, roots and callus were formed, but no plantlets.     

Changes in the starch content during organogenesis in in vitro cultured Begonia rex stem explants

Stem explants, excised from greenhouse-grown Begonia rex plants, were cultured on basal medium (T. Murashige and F. Skoog, Physiol. Plant. 15: 473–497, 1962) contained in sterile Petri dishes. The medium was supplemented with benzyladenine (0.1 mg 1⁻¹) naphthaleneacetic acid (0.01 mg 1⁻¹) and, according to experimental requirements, with either sucrose (3%) or mannitol (3%). Histochemical and biochemical examination of the starch content of the explant was carried out over several days. There was no starch deposition or organogenesis in tissue cultured on mannitol and carbohydrate-free growth medium. The most dramatic finding was the heavy accumulation of starch in tissue cultured on sucrose medium. This copious accumulation preceded any organ formation and was mainly in regions which ultimately gave rise to shoot primordia. The heavy build-up of starch preceding organogenesis was also observed when explants previously cultured on mannitol medium were transferred to medium containing sucrose. During shoot primordia development there was a decrease in the starch content of the cultured tissue indicating the utilization of the polyglucan in the organogenic process.     

龙船花两变种叶面积回归方程的建立

以龙船花两变种橙红龙船花Ixora coccinea var. coccinea、邦德胡卡红仙丹草I. coccinea var. bandhuca的成熟叶为材料,利用WinFolia软件测定多项叶形态指标,并对叶面积进行回归分析,分别建立其8种回归方程以及总的适用回归方程。结果表明,龙船花两变种的叶片长×叶水平宽、叶周长、叶垂直长、叶片长、叶水平宽、叶片长×叶片长以及叶水平宽×叶水平宽与叶面积之间的相关系数及复相关系数均呈极显著水平(P＜0.01),可分别用来建立龙船花的叶面积回归方程;叶面积与叶片长×叶水平宽的相关系数及复相关系数最高,基于叶片长×叶水平宽的8种叶面积回归方程更好地估测两种龙船花的叶面积。经检验发现,二次函数、复合函数、幂函数能更准确地估测叶面积;由两种龙船花共同建立的3种总的回归方程中,复合函数与幂函数能更好地模拟估测叶面积。     

火把花的繁殖生物学研究

火把花（Colquhounia coccinea?）表现出典型的鸟媒综合征,因此具有作为引鸟景观植物的开发潜力。以自然、人工生境的火把花居群为研究对象,通过观察和试验对其开花物候、花部综合特征、访花动物及其行为、繁育系统、种子萌发特性进行研究,以明确火把花的繁殖特性及对不同访花动物的吸引潜力。结果显示,火把花的整体花期持续约3个月,单花花期为9.6±0.6 d;花蜜较丰富且稀薄,具有较短的花冠管和己糖为主的花蜜糖组成;访花动物主要是中华蜜蜂和多种食蜜鸟类,尤其是短喙的泛化鸟类,且在非自然生境中仍然能吸引鸟类访花;完全自交亲和但需要传粉者才能完成授粉,不存在花粉限制;不同授粉处理种子的发芽能力无显著差异;中华蜜蜂能有效传粉,鸟类的传粉作用需进一步验证。综上所述,火把花可供观赏的时间很长,具有明显的吸引鸟类访花的能力,容易通过有性繁殖途径快速获得大量幼苗。     

Gradual Depletion of 2,4-D in the Culture Medium for Indirect Shoot Regeneration from Leaf Explants of Camellia sinensis (L.) O. Kuntze

Adventitious shoot regeneration via callus phase from in vitro leaf explants is reported for the first time in tea. Callus was obtained on Murashige and Skoog medium supplemented with varied concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) (2.5, 5.0, 7.5 and 10.0 mg/l). Rhizogenesis was observed at all concentrations of 2,4-D. Adventitious shoot buds developed indirectly on leaf explants after prolonged culture for 16 weeks on medium supplemented with 10.0 mg/l 2,4-D. GC analysis of the medium and the tissues at different stages of development showed that specific levels of 2,4-D in the tissue were responsible for morphogenesis. Shoot buds developed on rhizogenic calli, only when 2,4-D declined to undetectable or negligible concentrations in the tissue probably due to detoxification and metabolism. Alternatively, shoot buds could also be evoked when rhizogenic calli were transferred to medium supplemented with low concentration of 2,4-D (1.5 mg/l). The adventitious nature of the shoots was confirmed through histological studies.     

Direct Organogenesis from Mature Leaf and Petiole Explants of Eryngium Foetidum L.

Eryngium foetidum L. plants were regenerated from mature leaf and petiole explants through direct organogenesis without intervening callus phase. From leaf explants, adventitious multiple shoots raised on Murashige and Skoog (MS) medium supplemented with 4.43 M benzylaminopurine (BAP) and 0.57 M indole-3-acetic acid (IAA), whereas in petiole explants shoot regeneration occurred at 8.86 M BAP and 0.57 M IAAA. 80% of the leaf explants and 44% of petiole explants produced shoots after four weeks of culture. The regenerated plants were rooted on MS medium supplemented with 2.46 M indole-3-butyric acid and 2.88 M gibberellic acid. The plants were successfully established in the soil and showed 70.9% survival in the field.     

变色秋海棠的繁殖栽培

利用播种、扦插和组织培养 3种方式繁殖变色秋海棠均获得成功。播种繁殖的发芽率约 60 % ;在 3种不同的叶插繁殖中 ,以锥形叶插成活率最高 ;组织培养以叶片为外植体、MS+BA1 +NAA0 .1固体发芽培养基较好 ,从外植体直接分化出芽原基和新芽 ,属于器官型再生方式。利用密闭容器栽培法或类似此种方法栽培变色秋海棠 ,取得较好效果。     

Indirect Organogenesis from the Leaf Explants of Medicinally Important Plant Curculigo orchioides Gaertn

Curculigo orchioides Gaertn is an important medicinal plant of commercial value. A protocol for indirect regeneration from the leaf explants was developed. The leaf explants on MS (Murashige & Skoog) basal medium fortified with 6-benzylaminopurine (9μM) gave rise to proliferating green callus. The calli regenerated shoots on subculturing in the MS medium with 1.1μM 6-benzylaminopurine which was the optimum concentration for multiplication. Rooting was observed in MS medium supplemented with α-napthaleneacetic acid (5.3μM), indole-3-butyric acid (1.2μM), and on MS basal medium free of plant growth regulators. The rooted plants were hardened and transferred to field with 80% survival.     

Embryogenesis and Organogenesis in Pumpkin Explants

Embryogenic callus was induced by culturing explants of pumpkin hypocotyls on Murashige-Skoog-medium with the addition of 3% glucose and one of the following growth substances (or combinations of them): β-indolylbutyric acid, 2,4-dichlorophenoxyacetic acid, β-indolylacetic acid, α-naphthyl-acetic acid, adenine (natural), kinetin, autoclaved water-melon sap and yeast extract (Difco). A large number of embryoids and adventive buds were produced. These were able to develop to normal plants. The 17 strains of embryogenic tissue obtained have maintained their embryogenic characteristics for more than 3 years. The induction of embryogenic callus in pumpkin seems to be strongly dependent on the genetic constitution of each individual plant.     

云南秋海棠属三新种

尖被秋海棠　新种　图 1ＢｅｇｏｎｉａａｃｕｔｉｔｅｐａｌａＧｕａｎｅｔＴｉａｎ ,ｓｐ .ｎｏｖ .(Ｓｅｃｔ.Ｂｅｇｏｎｉａ)ＳｐｅｃｉｅｓＢ .ａｓｐｅｒｉｆｏｌｉａｅＩｒｍｓｃｈｅｒｅｔＢ .ｌａｂｏｒｄｅｉＬ啨ｖｌ.ａｆｆｉｎｉｓ,ｄｉｆｆｅｒｔａｂｉｌｌａｓｃａｐｉｓｅｆｏｌｉｏｌａｔｉｓ ,ｌａｍｉｎｉｓｆｏｌｉｏｒｕｍｎｏｎｌｏｂｕｌａｔｉｓｖｅｌｄｕｐｌｉｃａｔｏ -ｓｅｒｒａｔｉｓ ,ｔｅｐａｌｉｓｅｘｔｅｒｉｏｒｂｕｓｏｖａｔｏ -ｌａｎｃｅｏｌａｔｉｓａｐｉｃｅａｃｕｍｉｎａｔｉｓ;ａｂｈａｃｉｎ…     

34种秋海棠基因组大小比较与分析

以34种野生秋海棠(包括4个变种)为试材,水稻(Oryza sativa L.subsp.japonica Kato)为外标,采用流式细胞法测定其基因组大小,比较不同种、组之间基因组大小的差异,并分析与染色体数的相关性。结果表明:34种秋海棠基因组大小在0.292~2.554 pg之间,最大值约为最小值的9倍,平均基因组大小为0.863 pg,最小的为盾叶秋海棠(Begonia peltatifolia H.L.Li),最大的为水鸭脚秋海棠(B.formosana(Hayata)Masam.)。中国原产的30种秋海棠平均基因组大小(1C=0.925 pg)较南美洲原产的4种的(1C=0.398 pg)大,中国台湾原产的3种秋海棠基因组均比大陆原产的27种的大。中国原产秋海棠不同组间基因组的大小存在差异,同一组内基因组大小亦不相同,本研究所测材料以四室组的基因组最大,为1.285 pg,组内变化近3.2倍;秋海棠组和二室组次之,分别为0.895 pg和0.888 pg,组内变化近6.4、6.8倍;侧膜胎座组基因组最小,为0.721 pg,组内变化约1.2倍。相关性分析表明秋海棠基因组大小与染色体数无显著相关性。本结果可为秋海棠遗传多样性分析及基因组学研究提供一定的基础数据。     

五种中国秋海棠属植物的染色体数目

对 5种中国秋海棠属 (BegoniaL .)植物的体细胞染色体数目进行了报道 ,分别为 :小叶秋海棠B parvulaL啨ｖｌ.etVant .2n =2 8;石生秋海棠B lithophilaC .Y .Wu 2n =2 4 ;木里秋海棠B muliensisY櫣 2n =2 4 ;蕺叶秋海棠B limprichtiiIrmsch .2n =2 2 ;以及二室组sectionPlatycentrum的一个未知种B sp . 2n =2 0。     

丽格海棠的组织培养

由于丽格海棠通过扦插获得的量有限,进口种子的价格又很昂贵,所以以它的叶、茎、花茎、叶柄等营养器官作为外植体,进行组织培养来快速获得丽格海棠。通过诱导芽分化和诱导愈伤两种途径,研究不同植物生长调节剂及浓度,对外植体萌发和生根的影响。研究表明基本培养基为MS,最佳分化培养基为6-BA1．00mg／L NAA0．10mg／L;最佳生根培养基为1／2MS NAA0．mg/L;花土：沙子=1：1,是丽格海棠最佳的驯化移栽基质,在该基质中生根苗移栽成活率达90％。     

气孔在四季秋海棠营养器官和繁殖器官上的发育及相关性分析

主要观察了气孔在四季秋海棠营养器官和繁殖器官上的分布和发育情况,并分别对叶片和翅上气孔簇大小、气孔簇密度等指标的相关性进行了研究、结果表明:在叶片的下表皮、雌花和雄花的花被片、苞片、小苞片和翅上有气孔分布,而在茎、花梗上却未见气孔分布.叶片下表皮和翅上气孔通常成簇分布.在叶片的下表皮,气孔簇大小与气孔簇密度呈显著的负相关(P<0.05);气孔簇密度与叶片长度呈极显著的负相关(P<0.01).而翅上的气孔簇密度、气孔簇大小与子房长度无显著相关性(P>0.05).在四季秋海棠中,不同器官表皮的气孔簇大小是不同的,这可能与生理功能的不同有关.     

云南八种秋海棠属植物的染色体数目

对 8种 (变种 )中国秋海棠属 (BegoniaL .)植物的体细胞染色体数目进行了报道 ,分别为 :盾叶秋海棠BegoniacavalerieiL啨ｖｌ. 2n =30 ;角果秋海棠B ceratocarpaS .H .HuangetShui 2n =2 0 ;掌叶秋海棠B hemsleyanaJ .D .Hooker 2n =2 0 ;长果秋海棠B longicarpaK .Y .GuanetD .K .Tian 2n =2 0 ;红孩儿B palmatavar .browingiana (Champ .exBenth .)J .GoldingetC .Kareg .2n =2 2 ;大王秋海棠B rexPutz.2n =2 2 + 1B ;勐养秋海棠B mengyangensissub sp .mengyangensisM .C .TebbittetK .Y .Guan 2n =2 2 ;变色秋海棠B versicolorIrmsch . 2n =2 2。除掌叶秋海棠、大王秋海棠和变色秋海棠外 ,其余染色体数目均为首次报道。