Effects of seed chilling or GA3 supply on dormancy breaking and plantlet growth in Cercis siliquastrum L.

Germination and post-germination events have been compared in seeds of Cercis siliquastrum whose dormancy was removed by fulfilling the natural chilling requirement or by exogenous GA₃ application.Compared to the chilled ones, the GA₃ treated seeds showed precocious embryo growth and an earlier reserve mobilization, which started before radicle emergence.Although the hormonal application was interrupted at seed germination, the plantlets of Cercis siliquastrum that originated from GA₃-supplied seeds were taller than those from chilled ones. Moreover, they produced a greater number of leaves but a reduced root mass and had some difficulty in maintaining a good water balance.Thus, the treatment of Cercis siliquastrum seeds with exogenous GA₃ broke dormancy and induced germination, but also caused long-lasting consequences on morphogenesis of the growing plantlet.     

Leaf epidermal micromorphology of Cercis (Fabaceae: Caesalpinioideae)

The micromorphology of leaf epidermal cells and stomata of all eight species and one form (11 samples) of Cercis were observed by scanning electron microscopy and light microscopy. Both the adaxial and abaxial epidermal cells are polygonal or irregular in shape; the anticlinal walls are straight and arched or undulate. Two types of stomata, which occur only on the abaxial surface of the leaves, are found in the genus. The atypical paracytic type is present in only one species, Cercis chingii, and the anomocytic type is present in all other species. Interspecific differences are minor in the genus with regard to leaf epidermal characters, except for C. chingii, which is characterized by atypical paracytic‐type stomata, a two‐lipped outer stomatal rim, the highest stomatal density and undulate and densely pitted anticlinal walls in the adaxial epidermis. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 539–547.     

Inflated trichornes in flowers of Bauhinia (Leguminosae: Caesalpinioideae)

TUCKER, S. C., RUGENSTEIN, S. R. & DERSTINE, K. S., 1984. Inflated trichomes in flowers of Bauhinia (Leguminosae: Caesalpinioideae). An unusual kind of bifid multicellular inflated trichome is reported to occur on floral organs of II species of Bauhinia (Leguminosae-Caesalpinioideae), They occur on sepals, petals, stamens, carpels, receptacle, leaves, and stems, but not on all organs in each species. Their development in B. malabarica is described.     

紫荆属的系统发育和生物地理学研究

紫荆属（Cercis L.）约含8种,间断分布于亚洲东、西部、欧洲南部和北美。应用核糖体DNA的ITS基因序列研究紫荆属的系统发育关系。在最简约性分析,北美的两个种和南欧、西亚的一个种构成一单系群而隐藏于东亚的种类中。这表明紫荆属北美的种类和南欧、西亚的种类之间的关系比它们的各自与东亚的种类的关系要密切。研究还发现北美洲东、西部的种类可能具较近亲缘。紫荆属以白令陆桥或北大西洋陆桥为迁移途径的可能性似乎都不能排除;北半球的生物地理分布式样可具有复杂的起源。     

Comparative floral development and evolution in tribe Caesalpinieae (Leguminosae: Caesalpinioideae). Haematoxylum

Floral organogenesis and development of the tropical legume trees Haematoxylum campechianum (logwood) and H. brasiletto (brazilwood) were studied using scanning electron microscopy. The aims were to compare ontogenies, and to elucidate the relationships of Haematoxylum with other genera of Caesalpinieae, the basal tribe of Caesalpinioideae. Flowers of Haematoxylum are in racemes or fascicles, lack bracteoles, and are pentamerous, hermaphroditic, and either actinomorphic or zygomorphic. Whorls arise in acropetal order except for the carpel, which arises concurrently with the outer stamens. Sepal order is bidirectional (a rare condition) within the whorl in both. Petals and outer stamens are initiated bidirectionally in H. campechianum, and unidirectionally in H. brasiletto. Inner stamens are initiated unidirectionally in both. In H. campechianum, time of petal initiation overlaps with that of outer stamens, and initiation of the two stamen whorls overlap. In both, the gynoecium becomes stipitate, and a hypanthium forms late in development. Both show many plesiomorphic states at anthesis; H. brasiletto alone shows several specialized states (expressed late in development), including a fused, gibbous calyx cup, a zygomorphic corolla, lightly aggregated filaments held together by hairs, and fenestrations in the stamen column. Ontogenetic divergence late in ontogeny characterizes differences at anthesis between related species.     

Floral development in Tribe Detarieae (Leguminosae: Caesalpinioideae): Amherstia, Brownea, and Tamarindus

Floral development was compared among three taxa in caesalpinioid tribe Detarieae sensu lato: Amherstia nobilis and Tamarindus indica have racemose, helically arranged inflorescences, while Brownea latifolia has cauliflorous capitate flower clusters that arise as racemes. All have acropetal flower order; initiation and development are sequential in all except Brownea, which is synchronous. All have paired persistent showy bracteoles. Floral symmetry is dorsiventral (zygomorphic) in all except Brownea, with radial symmetry at anthesis. Sepals initiate helically on a circular floral apex, starting with a median abaxial sepal, in all. Petals are initiated helically in Brownea, and unidirectionally in Amherstia and Tamarindus. Stamens are initiated unidirectionally in each stamen whorl in all except Amherstia, in which the outer whorl is bidirectional. The carpel initiates concurrently with the petals in Brownea, and with the outer stamens in the other taxa. The two upper (adaxial) sepal primordia become fused during development in all, so that the calyx appears tetramerous. Some reduced petals occur in Amherstia and Tamarindus, and some reduced stamens occur in all. All produce a hypanthium by zonal growth, and all except Tamarindus have the gynoecium attached adaxially to the hypanthial rim.     

华南云实传粉生态学

在广东鼎湖山,华南云实(Laesalpinia crista L.)始花期从2月或3月开始,开花后约1周达到盛花期,盛花期持续2～4 d,花期可持续到4月底.华南云实基本繁育系统为雌蕊先熟、自交不亲和的异花受精.华南云实传粉方式为风虫媒.其主要传粉者为膜翅目昆虫,该种是云实属植物中首次报道的可行风媒传粉的种类.描述并探讨了华南云实花的结构与其主要传粉者木蜂之间的互动适应,并讨论了传粉生物学实验中的一些处理方法对华南云实开花过程的影响.     

华南云实传粉生态学(英文)

在广东鼎湖山,华南云实(LaesalpiniacristaL.)始花期从2月或3月开始,开花后约1周达到盛花期,盛花期持续2~4d,花期可持续到4月底。华南云实基本繁育系统为雌蕊先熟、自交不亲和的异花受精。华南云实传粉方式为风虫媒。其主要传粉者为膜翅目昆虫,该种是云实属植物中首次报道的可行风媒传粉的种类。描述并探讨了华南云实花的结构与其主要传粉者木蜂之间的互动适应,并讨论了传粉生物学实验中的一些处理方法对华南云实开花过程的影响。     

Martiodendron fluminense (Leguminosae, Caesalpinioideae), a new species from the Atlantic coast rainforest of Brazil

A new species of Leguminosae is described and illustrated:Martiodendron fluminense, the southernmost and the only species of the genus to occur in the Atlantic forests of southeastern Brazil.     

Genetics of seed storage proteins in the love tree Cercis siliquastrum L. (Fabaceae)

The patterns of C. siliquastrum seed storage proteins (cercins) are described using SDS-polyacrylamide gel electrophoresis. The polypeptides detected had very different molecular weights (ranging from 168 to 34 KDa) which, together with their high homogeneity, produced a very good resolution of bands. These proteins could be ascribed to five different loci. The analysis of seed sets of individual trees indicated that the love tree is almost completely autogamous with less than 5% of outcrosses. Although this mode of reproduction seems to produce a decrease in heterozygote frequency among the seeds of the population analysed, the levels of variability detected were very high for an autogamous plant: all of the loci were polymorphic, with a mean heterozygosity of 0.327 and a polymorphic index of 0.412. Protein segregation revealed a strong genetic linkage between three cercin loci (a, c and d) while the other two are independent.     

A new species of <Emphasis Type="Italic">Paloue</Emphasis> (Leguminosae: Caesalpinioideae: Detarieae) from Guyana,South America

Paloue sandwithii is described and illustrated from Kaieteur region, Guyana, South America. Characters that distinguish it from the other species of Paloue are the presence of five subequal petals and large coriaceous leaves with prominent venation on the underside of the lamina.     

Phylogenetic analysis of a polyphyletic African genus of Caesalpinioideae (Leguminosae): Monopetalanthus Harms

 To assess the new taxonomy of Monopetalanthus proposed by Wieringa, a phylogenetic study was performed using the chloroplast trnL intron and psbA-trnH spacer, and the nuclear ITS region of the 18-26S rDNA. The phylogeny clearly indicates the polyphyletic nature of Monopetalanthus. The molecular data support the transfer of M. longiracemosus to Tetraberlinia and the newly defined Aphanocalyx, which now includes all the previous Monopetalanthus species having leaflets with a marginal vein. Our analyses do not support the monophyly of the newly described genus Bikinia, which includes four new species and six species transferred from Monopetalanthus. Bikinia occurs either as paraphyletic with Tetraberlinia (chloroplast DNA data) or as a monophyletic group that also includes the new monotypic genus Icuria sister to Tetraberlinia (ITS data). Nonetheless, the molecular phylogeny generally supports the taxonomy of Wieringa in subdividing the genus Monopetalanthus into distinct groups, none of which retains the name Monopetalanthus. Received May 28, 2001; accepted July 6, 2002 Published online: November 20, 2002 Address of the authors: G. Y. Fannie Gervais, Anne Bruneau (e-mail: bruneaua@irbv.umontreal. ca), Institut de Recherche en Biologie Végétale, Université de Montréal, 4101 Sherbrooke est, Montréal, Québec, Canada, H1X2B2.     

Seed ontogeny of Chamaecrista and its systematic implications in Cassiinae (Leguminosae, Caesalpinioideae)

The genus Chamaecrista originates from the dismembering of Cassia L., which was elevated to the level of subtribe Cassiinae, giving rise to Cassia sensu stricto, Chamaecrista, and Senna. Phylogenetic analysis has suggested that Cassiinae is not monophyletic. The relationships between its genera are not clear, because they sometimes appear close to Chamaecrista and Senna and at other times close to Senna and Cassia. We describe here development of the seeds of three species of Chamaecrista and compare our data with information published in the literature for Cassiinae and non-Cassiinae legumes. The ovules appear well conserved in Cassiinae, differing only in the length of the funiculus. In terms of seed development, the shape of the endosperm haustorium is similar in Senna and Chamaecrista. Chamaecrista shares more characteristics of its mature seeds with Senna than with Cassia. Chamaecrista and Senna have variable seed shapes, the presence of pleurograms, the absence of root cap primordia, a short epicotyl, and the cotyledonary mesophyll tends to be dorsiventral. These seed characteristics place Senna close to Chamaecrista and distance it from Cassia. We also observed characteristics unique to Chamaecrista, for example the occurrence of multiple pleurograms, a partially multiplicative seed coat, and the presence of embryonic colleters.     

Apical pattern of fruit production in the racemes of Ceratonia siliqua (Leguminosae: Caesalpinioideae): role of pollinators

Fruit production and arrangement within the raceme were studied in two dioecious populations of Ceratonia siliqua (Leguminosae: Caesalpinioideae), an arboreal species that produces caulogenous racemes (emerging only from the old branches) with numerous flowers. Fruit production per raceme was low and similar between years and populations and even between individuals. During flowering, there were considerable flower losses from predation and lack of pollination. A mean of nine flowers per raceme began the transformation into fruits, of which 77% aborted. The final fruit production per raceme increased significantly following hand pollination, but was always very much lower than the availability of flowers in the raceme. The results suggest that fruit production of each raceme is limited by both availability of resources and a deficient pollination. In racemes setting fruit arrangement follows a definite pattern that remains constant between years and populations: fruit production was significantly higher in the apical zone of the raceme and lower in the basal zone. The pollinators of C. siliqua (flies and wasps) showed a clear preference for beginning their visits at the apex of a raceme. As a result, the pollen load deposited on the stigmas decreased from apex to base of the raceme. In most of the flowers situated in the central and basal zone of the raceme, the number of pollen grains deposited on their stigmas was lower than the number of their ovules. The high number of seeds in developed fruits suggests that the plant selectively aborts flowers that receive a smaller pollen load. The results indicate that the final pattern of fruit arrangement within the raceme is a direct result of pollinator activity.     

Development of protein bodies and accumulation of carbohydrates in a soybean (Leguminosae) shriveled seed mutant

The soybean seed mutant T311, when grown under specific environmental conditions, produces shriveled seed. This research investigated changes in development of protein bodies and accumulation of carbohydrates during seed development by comparing the mutant with P2180 seeds. The shriveled seeds contained larger protein bodies but fewer protein bodies per cell than round seeds. Protein bodies in T311 seeds included more dispersed crystals and less globoid regions than P2180 seeds. The elemental compositions of the crystals and of whole seeds in T311 were different from that in P2180 seeds. Starch breakdown was reduced with concomitant lower soluble sugar content in T311 seeds after the D11 stage (10.0-11.9 mm long seeds). The reduced starch breakdown and lowered soluble sugar content were consistent with lower a-amylase activity and earlier and greater water loss in T311 seeds. Changes in development of protein bodies and accumulation of carbohydrates were associated with the development of the shriveled seeds.     

Genetic diversity and structure of the endemic Caesalpinia hintonii complex (Leguminosae: Caesalpinioideae) in Mexico

The Caesalpinia hintonii complex is formed by five endemic species (C. hintonii, C. laxa, C. macvaughii, C. melanadenia and C. epifanioi) occurring in central Mexico. This species complex is under incipient genetic divergence as by-product of local adaptations in reproductive and morphological traits to different habitats. We estimate the genetic variation and structure of populations of this species complex to assess the extent of genetic differentiation among populations and related species along its geographic distribution. Estimations of genetic diversity and structure were done based on ten enzymes and 18 loci. Mean number of alleles per locus ranged from 1.5 to 1.9. Polymorphic loci ranged from 42.1 to 68.4. Observed (H_o: range 0.191–0.275) and expected (H_e: range 0.205–0.317) heterozygosities in this complex were higher compared with other endemic and legume species. Neis genetic diversity estimates showed that most genetic variation was found within (H_S = 0.325) rather than among populations (D_ST = 0.085). Populations of the species C. hintonii showed a considerable genetic differentiation (F_ST = 0.207). The results of genetic diversity and structure within and among populations are in accord with the great morphological differentiation described for this species complex.     

The unique pollen morphology of Duparquetia (Leguminosae: Caesalpinioideae): developmental evidence of aperture orientation using confocal microscopy

BACKGROUND AND AIMS: The phylogenetic affinities of the aberrant monotypic genus Duparquetia (subfamily Caesalpinioideae) are at present unresolved. Preliminary results from molecular analyses suggest a basal, isolated position among legumes. A study of Duparquetia pollen was carried out to provide further morphological characters to contribute to multi-data set analyses. Understanding the development of Duparquetia pollen was necessary to clarify the orientation of the apertures. METHODS: Pollen grains and developing microspores were examined using light microscopy, confocal microscopy and scanning electron microscopy. Evidence for the orientation of the apertures was provided by the examination of microspores within developing tetrads, using (a) confocal microscopy to locate the position of the ectoapertures, and (b) light microscopy and Alcian blue stain to locate the position of the endoapertures. KEY RESULTS: Confocal microscopy has been used for the first time to examine developing microspores in order to obtain information on ectoapertures that was unavailable using other techniques. Pollen in Duparquetia develops in tetrahedral tetrads as in other eudicots, with the apertures arranged in a modified pattern following Fischer's rule. Pollen grains are asymmetrical and have one equatorial-encircling ectoaperture with two equatorial endoapertures, a unique feature in Leguminosae, and in eudicots. CONCLUSIONS: The pollen morphology of Duparquetia is so unusual that it provides little information to help determine its closest relatives. However, it does fit with a pattern of greater pollen morphological diversity in the first-branching caesalpinioid legume groups than in the more derived clades. The latitudinal ectoaperture of Duparquetia is unique within the Fabales and eudicot clades, resembling more closely the monosulcate pollen found in monocots and basal angiosperms; however, developmental patterns are recognizably similar to those of all other legume pollen types.     

Evolutionary loss of sepals and/or petals in detarioid legume taxa Aphanocalyx, Brachystegia, and Monopetalanthus (Leguminosae: Caesalpinioideae)

Floral development using scanning electron microscopy is compared in several taxa of the Brachystegia subtribal group of caesalpinioid tribe Detariae. This group is characterized by missing sepals and/or petals. In Aphanocalyx djumaensis, Monopetalanthus durandii, and two Brachystegia species, one sepal is initiated in median abaxial position. In the first two, one or two additional sepal rudiments may initiate late. Brachystegia species have all five sepals, which remain scalelike. In Aphanocalyx and Monopetalanthus, one petal initiates adaxially and medianly (a position atypical for the first initiated petal in the family); additional petal rudiments may form in lateral sites. In Brachystegia, five petals are initiated unidirectionally on a meristem ring, but all are suppressed after initiation. In all taxa, ten stamens are initiated on a ring meristem: unidirectionally in Monopetalanthus, bidirectionally in Brachystegia, vs. in erratic order in Aphanocalyx. Carpel and petal initiation are concurrent. Different organ whorls overlap in time in Monopetalanthus and Brachystegia. In all, the floral apex characteristically is elongate radially and narrow tangentially after bracteole initiation. Two ontogenetic features, the meristem ring and the radially elongate post-bracteole floral apex, appear to be possible synapomorphies for the Brachystegia group.     

莲种子萌发和幼苗生长时期营养物质的代谢变化

莲子叶细胞中储存了丰富的营养物质,主要为蛋白质、淀粉和淀粉质体DNA.这些贮藏物质为种子萌发和幼苗的生长提供必需的能量和养料.通过组织化学和显微镜观察,研究莲从种子萌发到植株生长至具有4个节时,子叶中贮藏物质消耗的全过程.在此过程中,子叶中的贮藏物质不断降解,营养物质发生转运.蛋白体首先发生降解,其大量降解主要发生在幼苗三叶期.淀粉质体降解时会聚集成团,之后体积逐渐减小,最后完全降解.种子萌发后65天是子叶贮藏物质消耗末期,淀粉质体DNA的含量比萌发后20天的三叶期明显减少.细胞壁的形态结构发生多种形式的变化,细胞壁发生的这些变化与子叶细胞间物质的运输有关.含多糖的球形颗粒通过维管束在子叶中运输.