洋葱花器数目变异研究

以洋葱JQS-1、MST-140、Red beauty 3个常规栽培品种的鳞茎为试材,观察统计洋葱花器数目的变化,探讨花器数目的变异与植物花器多样性的关系,为植物花器发育模式以及植物分类和系统发育研究提供依据。结果表明:(1)洋葱花序中正常的洋葱小花含有6枚雄蕊,一些异常小花雄蕊的数目减少到5枚或增加到7~11枚;正常花药中的花粉粒数量大、形状规则、分散均匀,而异常花药中的花粉粒形状不规则。(2)雌蕊数目也发生变异,子房由正常的3室,变成了2室、4室或6室;花柱从正常1枚,增加到2枚或3枚。(3)正常小花含有6片花被片,异常小花的花被片数目从5片到10片。(4)花被片与雄蕊数目的变异有同步增减和非同步增加2种类型。     

蓝花丹二型花雌、雄蕊发育进程及内源激素对花柱生长的影响

为了解二型花雌、雄蕊发育进程及内源激素对长、短花柱生长发育的影响,以蓝花丹(Plumbago auriculata Lam.)为材料,观察分析了长花柱(L型)、短花柱(S型)花朵内雌、雄蕊的发育特征,并分别检测了L、S型花柱中的内源激素水平。结果显示:蓝花丹雌、雄蕊发育进程基本符合逻辑斯蒂变化曲线,并可划分为5个时期,即T1初始发育期、T2转折期(一)、T3快速发育期、T4转折期(二)、T5平稳发育期;在整个发育进程中,L型花朵中雌蕊的生长速率始终高于雄蕊;S型花朵中雌蕊的生长速率在T3期由快转慢,导致T3~T5期雌蕊的生长速率始终低于雄蕊,从而形成了雌蕊低于雄蕊的短花柱特征。这说明花柱的分化是在二型花雌、雄蕊快速发育的T3期开始出现,并逐渐形成花柱异长植物最显著的花部形态特征。IAA、IPA和GA含量均在T1~T3期增加、T4~T5期降低,且在L型花柱中的含量始终高于S型,而ABA含量的变化趋势与这3种生长促进类激素相反,说明在蓝花丹花柱发育过程中,IAA、IPA和GA可能参与调控花柱的伸长生长,而ABA主要在发育后期促使花柱成熟。     

秦岭石蝴蝶人工种群花器变异现象研究

以人工栽培的秦岭石蝴蝶为实验材料,通过观察并记录花器官形态和数目的变化,初步探讨秦岭石蝴蝶花器变异规律,并分析了导致其变异的诱因。结果显示:(1)在观察的1 996朵秦岭石蝴蝶花朵中,发现了17种花冠变异类型、5种萼片变异类型和7种可育雄蕊变异类型,总变异率分别为34.57%、38.38%和32.67%。(2)秦岭石蝴蝶花梗或可分支,花梗苞片数目2～3枚。(3)相关性分析结果表明,下唇数目与可育雄蕊数目呈正相关,相关系数为0.927 4,而上唇数目与可育雄蕊数目呈负相关,相关系数为-0.481 1,结合花型图示分析这可能与秦岭石蝴蝶雄蕊着生于花冠下唇内侧近基部有关。该研究统计的秦岭石蝴蝶变异类型丰富,可能对于今后秦岭石蝴蝶的系统进化、花器官发育、生殖生态以及分子遗传方面研究奠定了基础,也为培育不同观赏价值的品种提供思路。     

田埂报春多倍体诱导及其形态学研究

在离体培养条件下,比较不同浓度、不同处理时间的秋水仙素对田埂报春进行染色体加倍的诱导效果。结果表明:0.08%秋水仙素处理48h的诱变效果最佳,诱变率高达56%。经秋水仙素诱导后形成的多倍体植株与原二倍体植株比较,在形态上,四倍体植株表现出多倍体特征,叶片变厚,叶形指数减小,保卫细胞增大,单位面积气孔数减少,叶绿体数明显增多。对变异植株进行细胞学研究发现,体细胞中期染色体数目为2n=4x=36,而原二倍体的染色体数目为2n=2x=18,基数x=9,因此,变异植株(2n=4x=36)为四倍体。前者的核型公式为2n=4x=8L+12M2+4M1+12S,核型属于1A;后者的核型公式为2n=2x=4L+6M2+2M1+6S,核型也属于1A。检测发现少数个体有非整倍体变异。     

中间锦鸡儿(caranaga intermedia)染色体变异研究

对中间锦鸡儿(caranaga intermedia)种子根尖染色体进行检测,统计分析了染色体数目和结构变异类型.核型分析结果表明中间锦鸡儿正常核型为2n=2x=16=14m+2sm,还发现了核型公式为2n=2x=16+1B=1st+9m+2sm+1m(sAT)+1sm(SAT)+2m(SAT)+1B;核型公式为2n=2x=16+1B=6sm+8m+2m(SAT)+IB;以及核型公式为2n=2x=15=7sm+8m的变异类型.本研究首次发现了中间锦鸡儿存在B染色体和中间随体,此外还发现存在单体植株.随体具有个体差异,有中间随体和端部随体两种,且无论个体间和个体内B染色体均存在数目和结构的多态性.对其中120粒种子根尖染色体结果统计分析.发现具有15条染色体的植株占0.83%;具有16条染色体的植株占89.17%;具有17条染色体的植株占3.3%;具有18条染色体的植株占2,5%,其中有一个体中多于的一条染色体始终呈点状;19条染色体的植株占1.67%,5条多于染色体的占0.83%,而多余染色体条数在1～3之间变动的植株占1.67%.     

Ogura CMS紫菜苔×萝卜×甘蓝型油菜杂种的获得及细胞遗传学研究

以OguraCMS紫菜苔×萝卜杂种F1(AR ,2n =19)为母本 ,以甘蓝型油菜 (AACC ,2n =38)为父本进行杂交 ,获得了 4棵杂种植株。其中 1株 (PRN 1)的花色为嵌合体 ,该植株上的花多为黄色 ,但是也有乳白色花 ,另外还有 1朵花甚至 1个花瓣上同时具有黄色和白色区域 ,其余 3株 (PRN 2、 3、 4 )都开白花。PRN 4的花药开花前退化 ,其余 3株都可以看到 3～ 6枚花药 ,能够产生部分花粉 ,但是PRN 2的花粉不能被I2 KI溶液染色。PRN 2具有 4个蜜腺 ,PRN 1和PRN 3具有 2个蜜腺 ,PRN 4无可见蜜腺。在低温下PRN 2叶色正常 ,其余 3株幼叶表现不同程度缺绿。PRN 1的染色体数目为 2n =38,染色体平均配对构型为 14 6 7Ⅰ +10 0 7Ⅱ +1 0 6Ⅲ ,其染色体组构成可能是AACR ;PRN 2的染色体数目为 2n =35 ,染色体平均配对构型为 13 89Ⅰ +8 33Ⅱ +1 33Ⅲ +0 11Ⅳ ,PRN 3的染色体数目为2n =33,染色体平均配对构型为 14 0 0Ⅰ +7 82Ⅱ +1 0 0Ⅲ +0 0 9Ⅳ。PRN 4的染色体数目未能确定。与甘蓝型油菜回交后PRN 1～ 3植株各自产生了一定数量的种子 ,而PRN 4则未产生种子。对这些杂种及其后代的遗传及育种意义进行了讨论     

海石竹的离体快繁及核型分析

以海石竹 (Armeriamaritima)的叶片为外植体 ,经离体培养诱导产生愈伤组织 ,再分化形成不定芽 ,并经过继代增殖和壮苗生根 ,获得完整的再生植株 ,最后对其再生植株进行核型分析。结果表明 ,海石竹叶片的愈伤组织诱导和分化的适宜培养基为MS +BA 1 .0mg/L +NAA 0 .2mg/L ,诱导初期进行 7d暗培养 ,最佳增殖培养基为MS+BA 1 .0mg/L +NAA 0 .1mg/L ,生根培养基为MS+NAA 0 .2mg/L。以上培养基均含蔗糖3 0 g/L ,琼脂 5g/L ,pH 5 .8。海石竹的核型公式为 2n=2x=1 8=1 0m +8sm ,存在染色体数目变异的现象。     

异质生境对二型花柱植物雪地报春花性状分化的影响

该研究以生长在新疆北部的二型花柱植物雪地报春(Primula nivalis)为研究材料,对7个低海拔(1 657~2 013m)森林居群和7个高海拔(2 400~2 700m)草原居群的花型比例进行调查,对花部特征进行检测,并对长、短花柱植株在不同海拔居群的花性状分化进行了比较研究,以揭示该类群植物的演化与环境的关系。结果表明:(1)在高海拔草原居群中长花柱植株比例高于短花柱植株。(2)比较草原和森林生态系统中的雪地报春居群,长花柱花形态特征间存在显著差异,但短花柱花形态特征间的差异不显著。(3)高海拔草原居群中长花柱花的花冠筒长度、雄蕊长度、雌雄蕊距离、雌雄异位程度以及雌雄蕊空间位置是导致花性状分化的主要因素。(4)在草原居群中,长花柱花的雄蕊、雌雄异位程度及花冠口至雄蕊距离的变化减少了长短花柱花间的互补式对应性。研究认为,在异质生境中长花柱花性状的变化是导致该物种长短花柱花性状分化的主要因素。     

小叶杨与美杨种间杂交的胚胎发育和杂种胚珠的离体培养

1.观察了小叶杨(Populus simonii Carr.)和美杨(Populus pyramidalis Borkh.)人工杂交后从花粉粒萌发至胚分化完成的发育过程:1.大多数美杨花粉粒可以在小叶杨的柱头上萌发长出花粉管,花粉管在花柱中正常地生长并通过珠孔进入胚囊,于授粉后4—7天发生双受精作用,形成初生胚乳核和合子。胚乳的发育正常或不正常,后者表现为在游离核阶段的败育或胚乳细胞发育不良。胚在各个发育阶段尤其是球形胚和心形胚阶段,都可能败育,也可以正常发育成为分化完全的有效胚。2.将授粉后19天、22天、26天和29天含有不同发育阶段(心形期、鱼雷期、子叶伸长期)未成熟的杂种胚珠接种于人工培养基上,结果表明:1.M110培养基(1/2 MS+IAA 0.01毫克/升+BA 0.1毫克/升+蔗糖2%)是选用培养基中效果最好的;2.不同发育阶段杂种胚的胚珠可以离体培养成生长正常的小植株。     

南瓜两性花的形态与结构研究

对南瓜的两性花进行外部形态及结构的研究,结果表明：南瓜的两性花可有子房上位花、子房半下位花和子房下位花三种类型：花萼、花冠均为５,合瓣;雄蕊３,其中有两枚各由两个雄蕊合生而成,分离和部分联合,花药结构特殊,花粉发育正常;雌蕊具有单个或两个柱头及花柱。子房壁结构正常。上方的子房壁表皮发育完好,具气孔器。胚珠在外形上也发育正常。两性花与单性花同生长在一个植株上,可以连续多代稳定地遗传,萌生当代植株的种子来源于上一代雌花。这对探讨被子植物的系统进化关系有着重要的意义     

Floral Morphology of Populus lasiocarpa Oliv and Its Phylogenetic Position in Populus

The results of this study, which involved macroscopic, microscopic and SEM investigation of flowers of Populus lasiocarpa Oliv., may be stated as follows: 1. Female, male and bisexual flowers possess well developed perianth greenish in color with obvious veins and glandular teeth. The branched vascular bundles and stomata apparatus are observed in the transection of the perianth. It suggests that the perianth is homologous with the leaf. 2. Each pistil of female and bisexual flowere possesses 3(–5) separate styles. The ovary is I-celled with 16–34 ovules. Each male flower has 41–110 stamens. The connective of stamen is protrusive. Presence of bisexual, polygamous flower and monoecism is not rare. 3. In comparison with several other species of Populus, P. lasiocarpa is supposed to be the most ancient and primitive species of the Populus. The central and south-west China perhaps is one of distributional center of Populus.     

Archamamelis,hamamelidalean flowers from the Upper Cretaceous of Sweden

Lignite fossil flowers (including pollen) and isolated stamens of probable hamamelidalean (possible hamamelidaceous) affinities from the upper Cretaceous (Late Santonian or Early Campanian) of Sweden are described. The flowers are 6–7-merous with probably a double perianth, one whorl of stamens and (2-?)3 carpels. The stamens are disporangiate; each theca opens by a valve towards the centre of the flower. Pollen is tricolpate, tectate-columellate and reticulate; the endexine is lamellated in the apertural region. The gynoecium has free styles and a syncarpous ovary. In the one flower that was serially sectioned the ovary is either non-functional or development of the few (2?) ovules is retarded.     

Floral anatomy and systematics of Alliaceae with particular reference to Gilliesia, a presumed insect mimic with strongly zygomorphic flowers

The floral structure of Alliaceae is assessed in relation to the systematics of the family, especially the nature of the component parts of the remarkably insect-like flower of Gilliesia graminea. Both presence of solid styles and possession of tenuinucellate ovules represent consistent synapomorphies for Alliaceae and support the separation of Agapanthus and Themidaceae from Alliaceae. Within Alliaceae, absence of septal nectaries (i.e., complete fusion of carpel margins) is a synapomorphy for the sister genera Gilliesia and Gethyum; septal nectaries are present in all other Alliaceae. A gynobasic style and reduced ovule number are probable synapomorphies for the genus Allium. In contrast to most other Alliaceae, in Gethyum and Gilliesia only three (abaxial) stamens (A1, a1, a2) are expressed, as in the apostasioid orchid Neuwiedia, but the perianth of Gethyum is only slightly bilaterally symmetric (zygomorphic), whereas Gilliesia graminea shows bilateral symmetry in all three floral whorls: perianth (suppression of the inner adaxial tepal in most flowers), androecium (suppression of three adaxial stamens), and gynoecium (slight bilateral symmetry, evident in transverse section). The precise relationships of Miersia and Solaria, the other two genera of Alliaceae with bilaterally symmetric flowers, are unknown, but their morphology indicates a close relationship with Gilliesia and Gethyum. Appendages of tepaline origin occur in Gethyum, Gilliesia, and Miersia; their papillate epidermis suggests that they function as osmophores. Their presence in Miersia, which has six stamens, indicates that these novel structures, which develop late in floral ontogeny, evolved independently from stamen suppression in this group. Within Gilliesia graminea, the genetic mechanisms controlling tepal number and shape are apparently unstable, resulting in fluctuating asymmetry. In G. graminea the possession of insect mimicry, presence of osmophores and absence of nectar together indicate a deceitful pollination mechanism similar to that of some Orchidaceae; this would make Gilliesia highly unusual among non-orchid monocots, given that pollination by sexual deceit is normally regarded as exclusive to orchids.     

Discovery of Bisexual Flowers in Pterocarya Stenoptera C. DC.

This paper reports the bisexual structure of the flowers of Pterocarya stenoptera. The bisexual flowers are borne at the end of a leafy shoot of the current year in many-flowered terminal pendulous catkins. They have the same structure as the general female ones. Each flower grows in the axil of a bract, with a pair of bracteoles and four small perianths. Each flower has two or three carpels in the centre of the flower, and upon them there are two or three styles with stigmas on the inner face. They differ from the general female ones in that each of them contains 4-6 stamens, forming a single whorl. The stamens alternates with, or is opposite to, the perianth elements. Sometimes they contain 8 (-10) stamens, forming two whorls, with 6 in the outer whorl and 2 (-4) in the inner whorl, and in this case the pistil in the bisexual flower of terminal catkins often becomes a rudiment. It is interesting that we have also found bisexual flowers in another tree, which are borne in lateral male catkins. They have the same structure as general male ones, and the pistils are often represented by a rudiment. Manning (1940) points out that some female flowers of Pterocarya stenoptera and P. fraxinifolia occasionally have stamens ( ? ) opposite the sepals. In P. stenoptera we have found that both the stamens and the stigmas of bisexual flowers are functional. They are capable of producing functional fruits. This is the same case as in Myrica Gale described by Davey and Gibson (1917). Rendle (1952) points out that in the male flowers of Platycarya the pistils often appeared as a rudiment. He considers, however, the male flowers derived from the bisexual flowers with an indefinite number of stamens. The rudimentary pistils of lateral male catkins in P. stenoptera we found are just the same as the ones found in Platycarya by Rendle. The discovery of the bisexual flowers in P. stenoptera may prove that the unisexual flowers of the present-day Juglandaceae are derived from ancestors with bisexual flowers.This tends to support the hypothesis that Cycadicae is the possible ancestor of the angiosperms.     

千金榆花序及花器官发育

在扫描电镜下首次观察了桦木科鹅耳枥属千金榆花序和花的形态发生过程。千金榆雌花序由多个小聚伞花序螺旋状排列组成;每个小花序原基分化出1枚初级苞片和一团小花序原基分生组织,由小花序原基分生组织分化形成2个花原基和2个次级苞片;每个花原基分化出2个心皮原基,形成1个二心皮雌蕊;次级苞片远轴面发育快于近轴面,呈不均等的联合状;雌蕊基部有1层环状花被原基。雄花序为柔荑状,由多个小聚伞花序螺旋状排列组成;每个小花序原基分化出1枚初级苞片和一团小花序原基分生组织,由小花序原基分生组织分化出3个花原基分区,并分化形成3朵小花,小花无花被,位于两侧的小花分别有2枚雄蕊,位于中央的小花有4枚雄蕊,雄蕊共8枚,稀为10枚,该3朵小花为二歧聚伞状排列,其花基数应为2基数。     

Gender variation in Actinidia deliciosa,the kiwifruit

Summary Flower and fruit characters were measured in ten female, five male and five fruiting male selections of A. deliciosa var deliciosa (A. Chev) Liang and Ferguson. Flowers from female vines had functional pistils, which contained many ovules. Stamens appeared to be fully developed but produced only empty pollen grains. Flowers from male vines had functional stamens that produced high percentages of pollen grains with stainable cytoplasmic contents. Pistils did not contain ovules and were generally small with vestigial styles. Fruiting male vines had both staminate and bisexual flowers. Staminate flowers were similar to those found on strictly male vines. Bisexual flowers produced ovules and stainable pollen. Pistils were smaller than in pistillate flowers. Although the three flower sexes differed in style length, ovary dimensions and ovules per carpel, staminate and bisexual flowers were similar in number of flowers per inflorescence, stamen filament length, pollen stainability, inflorescence rachis length and carpel number, and differed from pistillate flowers in these characters. The three flower sexes had similar sepal and petal numbers. The fruit of fruiting males were considerably smaller than those of females. Low ovule number appears to be the major factor limiting fruit size in the fruiting males studied. Prospects for developing hermaphroditic kiwifruit cultivars through breeding are discussed.     

Variation and Phylogenetic Relationships Between Polygonatum odoratum and P. cyrtonema

The present paper is a report on combined cytological and taxonomical studies of Polygonatum odoratum and P. cyrtonema. Based on the extensive field observation and mass collection for some years, the authors made a detailed comparison of the variation pattern of morphology、cytology as well as geographic distribution between forms of P. odoratum and P. cyrtonema. The results show that: Form I: Stem angular, leaves elliptic, peduncles with one, rarely two flowers, perianth 1.7-2.0 cm long, stamens adnate to perianth in the middle part or a little lower. The karyotype formula is 2n=20=12m+8sm (2SAT); Form II: Stem angular, leaves narrow-oblong, peduncles with 2-3 flowers, perianth 2.8-3.2 cm long, the position of stamens on perianth is above the middle part. It has the karyotype 2n=20=8m+1osm(4SAT)+2st; Form III: Stem terete, leaves oblong-lanceolate, peduncles with 3- 10 flowers, perianth 1.5- 2.0cmlong, stamens are adnate to perianth also above the middle part. In this form, two kinds of karyotypes are found: 2n = 22 = 6m+8sm+8st and 2n = 20 = 4m+6sm (2SAT) +10st; Form IV: Stem terete, leaves elliptic, peduncles with 1-4 flowers, perianth 2.3-2.8 cmlong, stamens adnate to perianth above the middle part. The karyotype formulae are 2n = 20 = 4m+14sm (2SAT)+2st and 2n = 20 = 10m+10sm (2SAT); Form V: Stem terete, leaves oblong-lanceolate, peduncles with 3-5 flowers, perianth less than 2.0cm long, stamens adnate to perianth above the middle part. It is of the karyotype 2n=22=4m+8sm(2SAT) +10st. It is pointed out that the P. odoratum collected from the Qinling Range may be a hybrid or an intermediate in the evolutionary process from P. odoratum to P. cyrtonema. The differences between the different forms of P. cyrtonema are obvious and stable, and are probably derived from the chromosomal variation. The different forms of P. cyrtonema may have evolvedfrom P. odoratum along different courses.     

Floral ontogeny and systematic position of the Didiereaceae

Floral ontogenetical data from all four genera of the Didiereaceae (s.str.) are presented for the first time. All Didiereaceae s.str. are dioecious, having unisexual flowers with organ rudiments of the opposite sex. Two median bracts followed by a tetramerous perianth (two alternating dimerous ``whorls'), a slightly complex androecium with 6–12 stamens in a single row (on a common ring primordium), four of which mostly alternating with the perianth members, and one basal ovule connecting three free septa at their very base are flower characters in Didiereaceae, supporting phylogenetic analyses based on nucleotide sequence data. Closest relatives are the (formerly) portulacaceous genera Portulacaria (5 stamens alternating with the perianth), Ceraria (5 stamens alternating with the perianth), and Calyptrotheca (many stamens), all with pentamerous perianths, from which the tetramerous perianth in Didiereaceae can be derived. Applequist and Wallace (2003) included these three genera in an expanded family Didiereaceae (with three subfamilies).     

MORPHOLOGY,VASCULAR ANATOMY AND EMBRYOLOGY OF PISTILLATE AND STAMINATE FLOWERS OF ASPARAGUS OFFICINALIS

Flowers of three pistillate (female), two heterogametic staminate (male) and two homogametic male genotypes of Asparagus officinalis L. were compared for morphology and vascular anatomy of the flower and for embryological development to the stage of mature ovules and pollen. Flowers are liliaceous, the staminate with rudimentary pistils and the pistillate with collapsed anthers. The uncomplicated vascular pattern differs between staminate and pistillate flowers only in the size and degree of maturation of bundles to stamens and carpels. Longer styles appear to be correlated with a greater extent of ovule development in ovaries of staminate flowers. Microsporogenesis in males is normal with wall development corresponding to the Monocotyledonous type. The tapetum is glandular and binucleate, cytokinesis successive, the tetrads isobilateral or occasionally decussate, and the mature pollen grain two-celled. A pair of heteromorphic, possibly sex, chromosomes was observed in heterogametic male plants. Anther development is initially the same in pistillate flowers, but the tapetum degenerates precociously followed by collapse of microspore mother cells. In pistillate flowers the ovules are hemitropous, bitegmic, and slightly crassinucellate. Megasporogenesis-megagametogenesis conforms to the Polygonum type. In staminate flowers ovule development is like that in pistillate flowers until degeneration starts in nucellar and integumentary cells at the chalazal end. Ovules in both homogametic male genotypes rarely complete meiosis, while in the heterogametic males it is normally completed with about one ovule in 20 flowers forming a mature megagametophyte. Since manipulation of sex expression in Asparagus could be important in developing inbred male and female lines for breeding purposes, those aspects of the morphological and embryological observations presented which might be useful in planning experiments to induce sex changes are discussed briefly.     

ANDROMONOECY IN ZIGADENUS PANICULATUS (LILIACEAE): SPATIAL AND TEMPORAL PATTERNS OF SEX ALLOCATION

I describe patterns of sex allocation and gamete packaging in the andromonoecious lily Zigadenus paniculatus. In this species, pistil length was continuously, but bimodally, distributed within plants, and smaller pistils contained fewer mature ovules. In hermaphrodite flowers, ovule number per flower increased with blooming rank in small plants but decreased with blooming rank in large plants. Flowers with pistils less than three-fourths stamen length almost never produced fruits and were classified as males. The pedicel, tepals, stamens, and pistil of hermaphrodite flowers were all heavier than those of males. Hermaphrodite flowers were concentrated on the terminal raceme, males on the lower racemes. In combination with acropetal blooming, this spatial separation of flower types resulted in a seasonal decline in the proportion of open flowers that were hermaphrodite. However, individual flowers were protandrous, so that the population sex ratio, initially strongly male-biased, declined as the season progressed. Hand pollinations showed that plants were self-incompatible. Inflorescence size was positively correlated with bulb size, and plants with large inflorescences had a higher proportion of male flowers. Nutrient supplementation had no effect on inflorescence size, but increased the proportion of hermaphrodite flowers. Nutrient-supplemented plants also began blooming earlier than controls. I discuss these patterns in relation to the adaptive significance of andromonoecious breeding systems.