两种竹果的胚体类型及系统分类意义

竹类果实胚体类型复杂多样,中胚轴的有无,外胚叶的存在与否,盾片是否具有裂片,第一叶折叠或卷曲为大致的划分标准。胚的类型,胚芽、胚根与盾片的关系,胚体弯曲程度,中胚轴伸长程度及盾片的大小和形态等,在不同的种中有不同的特征。首次报道了花眉竹和融安黄竹这两种竹果的胚体类型分别为P+PP和F+PP及各自的特征,并探讨其系统分类的意义,为竹类植物的系统分类补充解剖学方面的证据。     

玉米胚胎发育、萌发与胚的结构及子叶二型性

运用扫描电镜与半薄切片技术,观察了玉米(Zea mays L.)的胚发育过程,得到以下认识：第一、关于原胚。玉米合子细胞分裂形成的原胚分为胚柄、胚基与胚体三部分。胚柄短小,寿命短暂。胚基具有生长带,纵向伸长长度大,胚基的上部参与形成胚根鞘,其余部分干缩后附在胚根鞘末端。第二、玉米胚的背腹极性及二型子叶。原胚初期胚体出现背腹极性,腹面的细胞小,细胞质稠密,液泡较少;背面的细胞较大,细胞质稠密度略低,液泡较多。原胚后期胚体分化为腹部与背部,腹部从腹面的中央突起,背部在腹部的周围(从左至右侧)及整个胚体背面。进入幼胚时期,腹部分化为胚芽鞘、生长锥、胚轴、胚根和胚根鞘(大部分)。期间,胚芽鞘原基和根原始细胞的分化都从胚体的中轴部位开始,然后向两侧和四周扩展,表现出胚体腹面形态的两侧对称性。原胚的背部形成盾片原基,盾片原基经历向左、右、上、下的迅速扩展和加厚的生长,将整个腹部所分化形成的构件藏于盾片的纵沟之中,最后盾片从纵沟的边缘长出的左、右侧鳞均向胚体的中轴线生长,完整显示出玉米胚腹面的两侧对称。玉米胚由腹部顶端形成胚芽鞘和生长锥的情况与水稻胚的胚芽鞘(顶生子叶)和生长锥的形成相同,玉米的胚芽鞘也是顶生子叶,盾片则是侧生子叶。玉米异型子叶的由来在于胚体的背腹极性。第三、玉米胚的真实形态结构及胚胎发育时期的划分。玉米胚是一个胚轴,其顶部是具胚芽鞘的胚芽,中部是具侧生子叶(盾片)的胚轴,下部是具胚根鞘的胚根。盾片从背面到腹面包住整个胚轴系统,在胚的腹面上可见从盾片边缘衍生的左、右侧鳞的边缘相迭,只在接缝线的上、下端留下蝌蚪状的小孔,使胚芽鞘和胚根鞘的末端稍露出。胚胎发育分为4个时期：1．原胚期——从合子细胞分裂开始至分化背部与腹部为止;2．腹部迅速分化期;3．盾片快速生长期;4．侧鳞生长、胚套形成期。第四、获取垂盲于胚腹面正中央纵切面是正确认识玉米胚形态的关键。     

玉米胚胎发育、萌发与胚的结构及子叶二型性

运用扫描电镜与半薄切片技术,观察了玉米(Zea mays L.)的胚发育过程,得到以下认识:第一、关于原胚.玉米合子细胞分裂形成的原胚分为胚柄、胚基与胚体三部分.胚柄短小,寿命短暂.胚基具有生长带,纵向伸长长度大,胚基的上部参与形成胚根鞘,其余部分干缩后附在胚根鞘末端.第二、玉米胚的背腹极性及二型子叶.原胚初期胚体出现背腹极性,腹面的细胞小,细胞质稠密,液泡较少;背面的细胞较大,细胞质稠密度略低,液泡较多.原胚后期胚体分化为腹部与背部,腹部从腹面的中央突起,背部在腹部的周围(从左至右侧)及整个胚体背面.进入幼胚时期,腹部分化为胚芽鞘、生长锥、胚轴、胚根和胚根鞘(大部分).期间,胚芽鞘原基和根原始细胞的分化都从胚体的中轴部位开始,然后向两侧和四周扩展,表现出胚体腹面形态的两侧对称性.原胚的背部形成盾片原基,盾片原基经历向左、右、上、下的迅速扩展和加厚的生长,将整个腹部所分化形成的构件藏于盾片的纵沟之中,最后盾片从纵沟的边缘长出的左、右侧鳞均向胚体的中轴线生长,完整显示出玉米胚腹面的两侧对称.玉米胚由腹部顶端形成胚芽鞘和生长锥的情况与水稻胚的胚芽鞘(顶生子叶)和生长锥的形成相同,玉米的胚芽鞘也是顶生子叶,盾片则是侧生子叶.玉米异型子叶的由来在于胚体的背腹极性.第三、玉米胚的真实形态结构及胚胎发育时期的划分.玉米胚是一个胚轴,其顶部是具胚芽鞘的胚芽,中部是具侧生子叶(盾片)的胚轴,下部是具胚根鞘的胚根.盾片从背面到腹面包住整个胚轴系统,在胚的腹面上可见从盾片边缘衍生的左、右侧鳞的边缘相迭,只在接缝线的上、下端留下蝌蚪状的小孔,使胚芽鞘和胚根鞘的末端稍露出.胚胎发育分为4个时期: 1.原胚期--从合子细胞分裂开始至分化背部与腹部为止;2.腹部迅速分化期;3.盾片快速生长期;4.侧鳞生长、胚套形成期.第四、获取垂直于胚腹面正中央纵切面是正确认识玉米胚形态的关键.     

竹类果实的形态解剖特征与系统进化

研究了２１属３９种竹子的果实形态解剖特征,发现其果实皮性质,喙的形状和质地,腹沟和胚盖的有无,糊粉层的厚度及胚的形状,可作为竹类的分属依据。依果皮性质,竹类果实可分为４大类：基本型颖果,浆果状颖果,坚果状颖果和半坚果状颖果。浆果状颖果可能是原始的类型,坚果状颖果可由其演化而来;半坚果状颖果可由坚果状颖果进化而来;基本型颖果既可能来自半坚果状颖果,也可能由浆果状颖果演化而来。原始竹果具有以下特点：果     

油松幼胚中几种酶的组织化学定位研究

油松(Pinus tabulaeformis)胚胎发育早期,未分化的幼胚中存在着三磷酸腺嘌呤核苷酶、酸性磷酸酶和过氧化物酶。前两种酶分布于胚体的全部细胞内。在胚柄中,主要存在于胚附近的1—3个胚柄细胞内。过氧化物酶的分布可因胚体大小不同而有变化;圆锥形幼胚的胚体及胚附近的胚柄细胞内显示出清晰的过氧化物酶活性,但是在柱状幼胚中,过氧化物酶主要分布在胚体基部及正在伸长的胚柄细胞中。实验结果表明,油松的幼胚细胞内有着多种酶以及旺盛的代谢活动,这些酶的存在可能与幼胚发育分化期间,对附近组织中物质的吸收、利用和转运有关。     

小麦不同生理状态的幼穗和幼胚盾片与诱导分化能力关系的研究

用植物组织培养的方法,研究了冬小麦品种鄂恩1号和品系鄂55072不同生理状态的幼穗和幼胚盾片与诱导分化的关系。结果表明,长度在0.4-2.0cm间的幼穗和直径在0.4-1.5mm间的盾片随生理状态不同,其诱导和分化频率有明显的差异,幼嫩的材料再生频率较高。经SAS统计分析,发现0.5-1.0cm长的幼穗和直径为0.4-1.1mm的盾片是处于诱导分化的最佳生理时期的实验材料,平均每个胚性愈伤组织的植株再生分别达到3.17和5.63株。通过比较幼穗和幼胚盾片的植物组织培养结果,发现幼胚盾片比幼穗愈伤组织出现早,生长快,植株再生绿苗率高,这表明小麦幼胚盾片是较好的植物组织培养的材料。     

稻胚发育的三维形态研究兼论胚各部分的形态本质

运用扫描电镜及塑料半薄切片技术,从水稻（ＯｒｙｚａｓａｔｉｖａＬ．）授粉后２ｄ开始至种子成熟,追踪观察了稻胚的三维形态发育,根据结果,对胚各部分的形态本质提出一些新的见解。（１）授粉后２ｄ的胚由胚柄、胚基和胚体组成。胚基为胚柄和胚体之间的过渡区,呈喇叭状,胚基与胚柄不能等同。２ｄ的胚未出现器官分化,属原胚;但胚背腹分化明显,即存在背腹极性。（２）授粉后第３至第５天幼胚的形态变化及器官分化至关重要。盾片和胚芽鞘在授粉后３ｄ的幼胚上同时出现,两者均直接由原胚分化,并非胚芽鞘从盾片发生。胚芽鞘原基经历这３ｄ的特殊形态演变,形成空心倒锥状的胚芽鞘,展现了禾本科特有的胚芽鞘的形态形成机理。３ｄ幼胚胚根的原形成层、基本分生组织及根冠分化;４ｄ幼胚小丘状生长锥形成,胚根的原表皮分化,茎根轴形成;５ｄ幼胚胚芽、胚轴与胚根初步形成。（３）稻胚具有二型子叶,胚套是胚的外围子叶,盾片是此子叶的一个主要部分（侧生子叶）,胚芽鞘是顶生子叶。     

谷子胚和胚乳的发育

合子的第一次分裂为斜的横分裂,胚发育至棒状原胚后,胚顶端一侧的细胞加速分裂形成一团分生组织细胞,由这团分生组织分化盾片、胚芽鞘、胚芽生长点和胚根。胚体的其它部分参与部分盾片和胚根鞘的构成。胚柄不参与胚的组成,胚无外胚叶,胚胎发育属禾本型。核型胚乳。从胚囊壁产生的自由生长壁把胚乳游离核隔开形成一层胚乳细胞。然后这层细胞平周分裂使胚乳细胞变成二层,以后的胚乳细胞增殖以细胞有丝分裂方式进行。胚乳的最外层     

我国主要禾本科植物幼苗发育基本类型与系统分类

本文在观察了代表22个族76个属的203种禾本科植物幼苗的发育过程和 各种性状的基础上,探讨了重要性状的形成与分布区、生境条件的关系及重要性 状之间的相关性。 根据胚轴和根系发育的不同形式,将禾本科幼苗划分为三大 型：竹型、狐茅型和黍型。根据苗叶和不定根的特点,又把这些大型分为七个 亚型：真竹亚型、稻亚型、芦竹亚型、针茅亚型、狐茅亚型、画眉草亚型和真黍亚 型。 经过与胚体和植株各方面数据的互相印证,证明与幼苗形态的七个亚型相 对应,在系统分类上是七个亚科：竹亚科、稻亚科、芦竹亚科、针茅亚科、狐茅亚科、画眉草亚科和黍亚科。     

小麦分离合子与幼胚中膜钙和钙调素的分布

用非酶手工显微解剖法分离小麦（ＴｒｉｔｉｃｕｍａｅｓｔｉｖｕｍＬ．）合子与幼胚。应用金霉素（ＣＴＣ）和氟奋乃静（ＦＰＺ）荧光探针,观察了合子与胚胎发育过程中膜钙和活化钙调素的分布。合子原生质体ＣＴＣ荧光呈极性分布。二细胞至十几个细胞原胚时期各细胞间的ＣＴＣ和ＦＰＺ荧光均匀分布。幼小梨形胚胚体ＣＴＣ和ＦＰＺ荧光稍强于胚柄。接近分化的梨形胚ＣＴＣ荧光仅位于胚体与胚柄之间的几层细胞和胚体腹侧中部的几个细胞中。胚芽刚分化时,胚基部ＣＴＣ荧光较强,ＦＰＺ荧光则仅出现在胚基部。讨论了合子分离技术和膜钙与钙调素（ＣａＭ）在胚胎发育中的可能作用。     

The Morphological and Anatomical Characters of Bamboo Fruits with Relation to Systematics and Evolution

The morphological and anatomical characteristics of bamboo fruits of 39 species in 21 genera have been surveyed. The results showed that characters as the shape, the middle cross section, the morphology of pericarp, rostrum and embryo, the presence or absence of ventral groove and embryotega, and the thickness of aleurone layer of fruits were the important features in identifying different genera, and also in studying systematics and evolution of the bamboos. All the bamboo fruits examined herewith could be considered as caryopses, and they could be subdivided into four types viz. typical, bacoid, nucoid and seminucoid type. Type A,typical,as most grass fruits, with thin pericarp throughout or thickened only at apex, ventral groove (hilum) and embryotega, was found in the majority of bamboos, such as Fargesia and Arundinaria. Type B, bacoid, with thick and fleshy pericarp, was found in nine genera: Melocanna, Dicochloa, Ochlandra,Olrneca, Melocalarnus, Chirnonobarnbusa ,Qiongzhuea, Ferrocalamus and Alvirnia. Type C, nucoid, with hard pericarp, was found so far only in Dendrocalamus and Cephalostachyurn. Type D,semi-nucoid, the intermediate type between type A and C, with pericarp, as in type A, in the dorsum and pericarp, as in type C in the ventrum was found in Sinocalarnus, PhyUostachys and Thyrsostachys. Bacoid may be the primitive type, from which nueoid may have evolved. Semi-nucoid may have evolved from nucoid. Typical type may be advanced and have evolved from bocoid or semi-nucoid. The primitive fruits of bamboos may have characteristics such as follows: globose or spheroidal in shape, round middle cross section; thick and fleshy pericarp throughout, less differentiated, presence of vascular bundle; absence of ventral groove (hilum) and embryotega; aleurone layer composed of a number of cell layers; large and curved'or folded embryo. Bamboos with such a fruit have iterauctant inflorescences except Ferrocalamus.     

利用秆维管束进行中国散生竹类的聚类分析

本文是应用模糊聚类分析方法研究中国散生竹类分类的一次尝试。分类特征采用了竹秆上、中、下三段各类型维管束数,方法上使用了模糊(Fuzzy)直接聚类分析进行综合分析。经电子计算机运算后,不仅取得了与传统分类基本一致的分类结果,同时也表明这种方法较之其它一些植物数量分类方法简便易行,此外还讨论了一些中国散生竹类分类上的问题。     

Bamboo dominance reduces tree regeneration in a disturbed tropical forest

Human disturbance may change dominance hierarchies of plant communities, and may cause substantial changes in biotic environmental conditions if the new dominant species have properties that differ from the previous dominant species. We examined the effects of bamboos (Bambusa tulda and Cephalostachyum pergracile) and their litter on the overall woody seedling abundance, species richness and diversity in a mixed deciduous forest in northeastern Thailand. These bamboo species are gaining dominance after human disturbance. Our results show that seedling abundance and species richness were reduced by bamboo canopies. Seedling abundance and species diversity under bamboo canopies were affected by bamboo litter, whereas seedling abundance and species diversity outside bamboo canopies did not respond to the mixed-tree litter manipulation. Removal of bamboo litter increased seedling abundance and species diversity. However, bamboo litter addition did not affect seedling abundance or species diversity compared to either control or litter removal. This may indicate that the effect of natural amount of bamboo litter is as high as for litter addition in preventing seedling establishment by woody species and hence in minimizing resource competition. We conclude that undergrowth bamboos and their litter affect tree seedling regeneration differently from mixed-tree litter, causing changes in plant community composition and species diversity. Increased human disturbance, causing a shift in dominance structure of these forests, may result in a concomitant reduction in their overall woody species abundance, richness and diversity. Thus, management of bamboos by controlling their distribution in areas of high bamboo density can be an important forest restoration method.     

Specialization on Guadua Bamboo Seeds by Three Bird Species in the Atlantic Forest of Argentina

Most bamboos are semelparous. Their synchronous masting events occur on a cycle of 3–120 yr and represent an extremely pulsed resource for granivorous birds. Although many bird species feed occasionally on bamboo seeds, there are constraints to specializing on such a fluctuating resource and few bird species are known to specialize on bamboo seeds. Three of these bird species are endemic to the Atlantic forest of South America: the purple-winged ground-dove Claravis godefrida , buff-fronted seedeater Sporophila frontalis , and Temminck's seedeater Sporophila falcirostris . All three species are irregularly recorded in the province of Misiones, Argentina. We compared the temporal and spatial patterns of records of these birds in Misiones to masting events of the five common bamboos: yatevó Guadua trinii , takuaruzú Guadua chacoensis , takuapí Merostachys claussenii , pitinga Chusquea tenella , and takuarembó Chusquea ramosissima . All bird records coincided with times and places where Guadua bamboos ( G. trinii and G. chacoensis ) were known or estimated to have seeds. None of the bird species occurred during masting events of Merostachys or Chusquea , unless Guadua was also masting. We discuss relevant ecological and morphological features of the birds that might bear on their association with Guadua bamboos and that might be key to their conservation.     

The Morphology of Fruits and Starches in Bamboos,and Its Relation to Systematic Position

In this article, 30 speceis of bamboos, including 19 genera in 5 tribes, were collected and the morphology of fruits and starches of them was studied. The results are as follows. I. The morphology of fruits is important in studies of systematic position in bamboos. According to the systems of W. Munro and G. Bentham whether the pericarp is adhesive to or free from the seed coat may be taken as a basis of classification. It is also confirmed in this article. It is found in this work that all taxa with a binding pericarp and seed coat are of caryopsis that also has a ventral suture and hilum, while all others with a separated pericarp and seed coat are of bacca or nut, which has no ventral suture and hilum. The former has a hard and thin pericarp and rich endosperm, while the latter has a fleshy and thick pericarp and no endosperm. These characteristics form a basis of classification of major groups. II. In 1907, Brandis found that no any endosperm in matured fruit of Dinochloa, Melocalamus, Melocanna and Ochlandra. It has been proved by Stapf in at least one genus. We found that the baccae of Qiongzhuea, Melocanna, Ferrocalamus and Chimonobambusa Subg. Oerocalama were empty, with no endosperm. This may be a common character of the bacca. We believe, therefore, that the systematic position of Qiongzhuea, Ferrocalamus and Chimonobambusa Subg. Oreocalama is close to Melocanneae. III. Starch grains of bamboo fruits are complex in structure. They are round or ellipsoidal, consisting of 3-22 polyhedral or apple-like small grains. The morphology of starch grains is not so important as fruit in bamboo classification, but some characteristics are of a high value in the identification of genera and species, when they are combined with other features. In Cephalostachyum, the starch grain is very big, with 20-40 μm in diam, and the starch small grain is polyhedral or apple-like with 7.5-22.5 μm in diam, while in Dendrocalamus, the starch grain is small, with 10-28.9 μm in diam. and the starch small grain is only polyhedral, with 3-11.9 μm in diam. The morphology and size of the starch grain and starch small grain are also different in Melocanna and Chimonobambusa Subg. Oreocalama. IV. W. Munro’s system divided Bambuseae into three major groups according to the morphology of flower and fruit. Because the material was not sufficient at that time, the system wrongly put Cephalostachyum, Dendrocalamus into the group Bacciferea. Now it is found that both Cephalostachyum and Dendrocalamus have a nut. Later G. Bentham found this problem and divided the Bambuseae into four subtribes, treating Dendrocalamus as a separate subtribe, Dendrocalamae, and putting the bacca group into another subtribe, Melocannae. It is better, but it also has some shortcomings. Hackel, Gamble, E. G. Camus, A. Camus and Keng Pojie all accepted the view of Bentham, placing Dendrocalamus and Melocanna into different subtribes or tribes.     

中国竹类植物馆藏标本现状与地理分布

馆藏标本是分类学研究的主要凭证, 对特定类群标本的采集信息进行细致整理和分析, 有助于理解该类群研究的历史、现状和不足。此外, 结合最新的系统学研究成果和相应的环境数据构建生态位模型, 可以加深人们对特定类群分类与分布状况的认识。被子植物的分类鉴定常基于繁殖性状进行, 然而, 竹类植物一般进行克隆繁殖, 只有在经过长期的营养生长之后, 才会进行有性生殖并同时死亡。因此, 国内的竹类标本大多仅记录了营养性状, 具有繁殖性状的标本数量稀少。由于这一特殊的生物学习性, 竹类植物是当今分类学研究中最为困难的类群之一。本研究基于全国竹类植物馆藏标本的采集数据, 分析了我国竹类标本的采集和保藏现状; 利用比值法和斜率法从采集地理偏差和采集类群偏差两方面评估了竹类植物标本的采集完整度; 结合气候数据, 利用模型模拟的方法分析了影响不同竹类分支分布的主要因素。采集信息分析结果表明, 国内标本馆对竹类标本的收集和保藏存在很大的不均衡性, 且对研究团队具有较高的依赖性; 其次竹类标本的采集量的变化较好地反映了国内植物分类学研究的历史; 而对类群和地理采集完整度的评估结果表明, 中国竹类标本的采集和整理工作仍任重道远。模型模拟结果表明, 温度限定了竹类植物两大分支各自的分布北界, 水分对温带木本竹类分支(temperate woody bamboos, TWB)的限制作用比旧世界热带木本竹类分支(paleotropical woody bamboos, PWB)强, 而温度对PWB的限制性更强。生态位模拟的结果进一步显示, 中国温带和旧世界热带木本竹类两大分支的适生区出现了明显的分化, 但在亚热带区域仍有部分重叠。植物标本记录了特定类群在时间和空间上的分布格局, 相关的信息一方面可以促进物种灭绝风险评估、可持续利用和综合保护, 另一方面也可助力大尺度生物多样性分布格局及全球变化对多样性的影响研究。     

Endophytic fungi and silica content of different bamboo species in giant panda diet

The giant panda (Ailuropoda melanoleuca), one of the most threatened mammalian species in the world, has adapted to herbivorous diet consisting mainly of bamboo (Poaceae: Bambusoidea). The most acute threats to the survival of the giant panda are habitat loss and fragmentation. However, changes in habitat may influence also the quality of giant panda diet through the bamboo species composition as well as their symbiotic leaf endophytes and plant chemical properties. Here we explore species composition and frequency of endophytic fungi and silica content in different bamboo species in the range of giant panda habitat in relation to panda food preference. Silica content of the bamboos varied from 3.7 g/kg to 45.7 g/kg and did not correlate with panda preference and altitudinal gradient. Systemic and vertically in seeds transmitted fungal endophytes or bacterial endophytes were not detected in bamboo leaves. Nearly half of the identified endophytic fungi belonged to genus Arthrinium. Pandas preferred bamboo species naturally occurring in higher altitudes. Furthermore, the total amount of endophytes tended to be lower in samples collected from bamboos in higher altitudes. This draws attention to the importance of more detailed studies on the endophytic fungi-bamboo-panda trophic interactions and the effect of land use and climate change on conservation programs of giant panda.     

Research on ecological stoichiometry in bamboos: From biological basis to applications in silviculture of bamboo forests

Bamboo ecology and nutrient management require guidance of a set of theoretical principles. By focusing on the contents of multiple nutrient elements and their ratios and summarizing recent research findings in biology, ecology and silvics of bamboos, this paper seeks to establish the bamboo ecological stoichiometry (BES) in order to support the sustainable development of bamboo forests. It is considered that: (1) bamboos have the ubiquitous characteristics of stoichiometry, with average leaf C:N:P of 380:16:1, which complies to the “homeostasis hypothesis”; (2) the internal factors such as organs, ages and development stages and the external factors such as soil, climate and harvest can all affect the characteristics of bamboo stoichiometry; (3) changes in the ecological stoichiometry of bamboos affect the bamboo biological and ecological processes including photosynthesis, nutrients uptakes, flowering, shootings and growth, community dynamics, and qualities of bamboo products; (4) the principles of BES have been preliminarily used to guide the nutrient diagnosis, balanced fertilization, and production of high-quality and high-yield bamboos. As a new tool, BES can be further improved to integrate biology and silviculture under the background of ecological and environmental protection and food safety. Future research should place more emphasis on elucidating the ecological homeostatic mechanisms for more bamboos, as well as on understanding the stoichiometric principles in producing high-quality bamboo shoots, the bamboo-soil stoichiometric interaction processes, the nutrient diagnosis and stoichiometric balanced fertilization, and the optimal ecosystem management of bamboo forests.