Pollen morphology inParis and its related genera

Pollen grains ofParis, Medeola, andScoliopus have been examined with light, scanning electron, and transmission electron microscopies.P. quadrifolia L.,P. verticillata Bieb.,P. delavayi Franch. andP. polyphylla Smith have monosulcate pollen characterized by psilate, foveolate or reticulate exine sculpture. In contrast to the former species,P. japonica (Fr. et Sav.) Franch. andP. tetraphylla A. Gray have monosulcate pollen with gemmate (rarely rugulate) exine.Medeola has monosulcate pollen with reticulate exine that is distinct from that ofParis. Scoliopus has monosulcate pollen characterized by a peculiar reticulate exine pattern. The palynological evidence suggests thatParis andTrillium are closely related to each other, andMedeola andScoliopus should be separated fromParis andTrillium.     

Preparation of the tritiated molecular forms of gangliosides with homogeneous long chain base composition

Gangliosides G_M2, G_M1 and G_D1b were radiolabelled at C-6 of the terminal galactose orN-acetylgalactosamine by the galactose oxidase/[³H]NaBH₄ method; gangliosides G_M2, G_M1, Fuc-G_M1 and G_D1a were radiolabelled at C-3 of the long chain base by the 2,3-dichloro-5,6-dicyanobenzoquinone/[³H]NaBH₄ method.By application of an original HPLC procedure, eight different molecular species were prepared from each labelled ganglioside. Each of these species was characterized by the presence of one of the following long chain bases:erythro C18 sphingosine,threo C18 sphingosine,erythro C18 sphinganine,threo C18 sphinganine,erythro C20 sphingosine,threo C20 sphingosine,erythro C20 sphinganine andthreo C20 sphinganine.From G_D1b only the species containing theerythro forms of long chain bases were obtained.The individual molecular species were more than 99% homogeneous and had a radiopurity better than 99%. The molecular species of the same ganglioside, radiolabelled at C-3 of the long chain base, had identical specific radioactivity, namely 1.17, 1.25, 0.85 and 1.28 Ci/mmol for G_M2, G_M1, Fuc-G_M1 and G_D1a respectively. The molecular species of the same ganglioside, radiolabelled at C-6 of terminal galactose orN-acetylgalactosamine, had similar specific radioactivity, namely 1.34–1.40, 1.44–1.51, 1.37–1.44 Ci/mmol for G_M2, G_M1 and G_D1b respectively.     

Intraspecific Genetic Diversity of Undaria pinnatifida in Japan, based on the Mitochondrial cox3 Gene and the ITS1 of nrDNA

The intraspecific genetic diversity of the kelp Undaria pinnatifida (Harvey) Suringar (Laminariales, Phaeophyceae) was investigated using DNA sequences of the mitochondrial cytochrome oxidase subunit 3 (cox3) gene and internal transcribed spacer 1 (ITS1) of nuclear ribosomal DNA in plants collected from 21 localities along the Japanese coast between 2001 and 2003. Morphological variation was also examined and compared with the genetic diversity. Cox3 analyses of 106 plants revealed 9 haplotypes (I–IX) that differed from each other by 1–7 bp (all synonymous substitutions). Haplotype I was distributed in Hokkaido and the northern Pacific coast of Honshu, while haplotype III was found along the Sea of Japan coast of Honshu. Other types were found along the central and southern coast of Honshu. ITS1 analyses of 42 plants revealed 0–1.7% nucleotide differences, but plants from the Sea of Japan coast and northern Japan had similar sequences. The lower genetic differentiation along the Sea of Japan and northern coasts might be due to the recent establishment (after the middle of the last glacial period) of the Sea of Japan flora. The cox3 haplotype of cultivated plants was found in natural populations occurring close to cultivation sites (Naruto, Tokushima Pref., and Hokutan, Hyogo Pref.). This suggests that cultivated plants possibly escaped and spread or crossed with plants of natural populations. Morphological analyses of variation in 10 characters were conducted using 66 plants. The results showed no significant local variation owing to the wide variation in each population and did not support any forma previously described. No correlations between the morphological characters and cox3 haplotypes were detected.     

Interaction of gangliosides with plasma low density lipoproteins

The role of gangliosides in the reception of low density lipoproteins (LDL) was studied using as targets mouse ascites hepatoma 22a (MAH) cells which bind LDL through a specific high affinity receptor. Low density lipoprotein binding and uptake by MAH cells decreased after brief treatment of the cells with neuraminidase to partially remove surface sialic acid residues. The LDL uptake capability of the neuraminidasetreated MAH cells was fully restored after incorporation of exogeneous G_M1- and G_D1a-gangliosides into the cell surface. In contrast, free (extracellular) gangliosides inhibited LDL uptake by native MAH cells. This inhibitory effect was seen at ganglioside concentrations corresponding to the ganglioside content of serum and was most pronounced with gangliosides whose sialic acids were linked to a terminal galactose residue (G_M3, G_D1a, G_T1b) but was smaller or absent with gangliosides whose sialic acids were attached to an internal galactose (G_M1, G_M2). The binding of gangliosides to LDL was structure and concentration dependent, saturable and trypsin sensitive. The LDL-ganglioside interaction was further investigated by steady state fluorescence spectroscopy. Changes in the LDL fluorescence polarization were observed with as little as 0.01 M concentrations of the gangliosides. The magnitude and nature of the effect depended on the type of ganglioside. We conclude that the LDL surface possesses sites recognizing specific carbohydrate sequences of glycoconjugates and that changes in the cell surface concentrations of sialic acids significantly modulate the LDL uptake. It is postulated that shedding of gangliosides into the blood stream may be a factor involved in regulation of cholesterol homeostasis.Abbreviations MAH mouse ascites hepatoma 22a - LDL low density lipoprotein - ASM anthrylvinyl-labeled sphingomyelin [N-12-(9-anthryl-trans-dodecanoyl-sphingosine-1-phosphocholine] - RITC rhodamine isothiocyanate. The designation of gangliosides follows the IUPAC-IUB recommendation [1]: G_M3, II³NeuAc-LacCer, II³-N-acetylneuraminosyllactosylceramide - G_M2 II³-NeuAc-GgOse₃Cer, II³-N-acetylneuraminosylgangliotriaosylceramide - G_M1 II³-NeuAc-GgOse₄Cer, II³-N-acetylneuraminosylgangliotetraosylceramide - G_D1a, II³ IV³(NeuAc)₂-GgOse₄Cer, II³, IV³-di(N-acetylneuraminosyl)gangliotetraosylceramide - G_T1b II³(NeuAc)₂, IV³ NeuAc-GgOse₄Cer, II³-di-N-acetylneuraminosyl, IV³-N-acetylneuraminosylgangliotetraosylceramide     

全球陆地生态系统光合作用与呼吸作用的温度敏感性

基于全球647套通量数据,定量分析了全球尺度下生态系统光合作用和呼吸作用的温度敏感性(Q10)随纬度、气候和植被的分布规律。结果表明:在全球尺度下,光合作用和呼吸过程的温度敏感性(Q10,G和Q10,R)都随纬度的升高而增加,其中Q10,G和Q10,R的均值分别为3.99±0.21和2.28±0.074。除热带多树草原、常绿落叶林外,Q10,G均大于Q10,R值。不同植被类型的温度敏感性存在显著性差异,表现为:针叶林阔叶林;落叶林常绿林,其中生态系统的季节性变异是造成差异的主要原因。当植被类型和纬度区域共同影响Q10值时,植被类型对Q10值的总变异贡献更大。气候类型对Q10,G和Q10,R都有显著影响。在气候带上,干旱带的Q10,G最小,而冷温带的Q10,G最高。不同气候类型下(除温带草原气候外)的Q10,G都大于Q10,R。在极端条件下,温度可能不在是主导因素,而水分对温度敏感性的影响不可忽略,今后的研究需要更多的关注生态系统温度敏感性对水分变化的响应。     

Somaclonal variation in high tannin sorghums

Summary Genetic variants were found among over 6,000 primary plants (R₁) regenerated from embryogenic tissue cultures of eight high tannin sorghums [Sorghum bicolor (L.) Moench]. Field assessment of somaclonal variation has progressed to the R₂ population, with over 48,000 R₂ seedlings (27,000 plants) in 1,126 rows from 1,055 R₁ plants. A total of 43 variant phenotypes was recovered, including several types of chlorophyll deficiencies, dwarfism, short culm, sterility, narrow leaf, and several previously unreported variants, such as ragged leaf, multibranched heads, and Hydra, a developmental variant which produces large numbers of panicles. Variation production greatly depends on parent genotype and appears to increase with increasing time in cultures. The toal average somaclonal variation rate (based per 100 R₁ plants) and somaclonal variant frequency (based per 100 R₂ plants) estimated in the tested population were 11.3 and 1.6, respectively. Chimerism was found in regenerants. The estimated size of the mutated sector carried by mutant regenerants ranged from the whole plant to less than 3% of a single head. The average proportion of mutated R₁ heads carrying large (80%–100%), medium (40%–80%), and small (<40%) mutated sectors was 38.7%, 26.0% and 35.3%, respectively. Some sector mutations do not appear until the R₃ generation. In order to avoid losing variants, the population for selecting somaclonal variation should be as large as possible. Some of these variants found may be useful for further study or for use in breeding programs.     

巨桉和天竺桂幼树对不同浓度SO2的光合生理响应

二氧化硫是大气主要污染物之一,可对植物的关键生理过程光合作用产生重要影响。利用密闭环境控制室熏气处理,研究不同浓度(自然状态下浓度、0.5mg·L-1、1.5mg·L-1、3.0mg·L-1)SO2对盆栽巨桉和天竺桂幼树叶绿素含量、光响应曲线、光合特征参数、光合日变化及硫含量的影响。结果表明:(1)SO2胁迫显著减少了巨桉叶绿素a、b含量,且叶绿素a/b值显著降低,而天竺桂在SO2胁迫下叶绿素a、b含量显著增加,叶绿素a/b值无显著影响。(2)SO2胁迫显著抑制了两树种的净光合速率(Pn);在SO2胁迫下巨桉气孔导度(Gs)、胞间CO2浓度(Ci)和蒸腾速率(Tr)显著上升,而天竺桂的Gs和Tr显著被SO2抑制,Ci随SO2浓度的增加先升高后降低。(3)巨桉表观量子效率(AQY)、暗呼吸速率(Rd)、光补偿点(LCP)和光饱和点(LSP)及天竺桂Rd和LCP均随着SO2浓度的增加而先升高后降低,而天竺桂的AQY和LSP逐渐降低。(4)一天中,SO2胁迫显著提高了巨桉Pn、Gs和Tr,而对天竺桂Pn无显著影响,较低浓度SO2胁迫显著促进了天竺桂Gs和Tr,高浓度SO2胁迫则显著抑制其Gs和Tr;SO2胁迫显著抑制了两种植物的Ci。(5)SO2胁迫下,巨桉和天竺桂幼树叶片硫含量均显著增加。研究认为,巨桉对较低浓度的SO2胁迫有一定的适应能力,但对高浓度SO2胁迫的抗性不如天竺桂强,这可能与二者不同的叶片形态及生理特性有关。     

Morphologic,cytogenetic, and enzymatic variation in tissue culture regenerated plants of apomictic old-world bluestem grasses (Bothriochloa sp.)

Somaclonal variant plants may be of use in broadening the germplasm base of plant species and providing useful stocks for cytogenetic investigations. This study was conducted to compare morphologic, cytogenetic and enzymatic characteristics of 21 R₁ (initial regenerate) bluestem,Bothriochloa sp., plants, visibly identified in a field-grown population of 522 plants as probable variants, with their respective R₀ (explant donor) progenitor. An R₂ seedling population was grown to ascertain the transmission of the variant R₁ phenotypes. All R₁ plants differed from their respective R₀ progenitors in one or more morphological characters. Foliage colour was the most pronounced difference in most cases. Four of the plants, three of which were dwarfed, produced no inflorescences. The R₁ plants tended to be shorter than R₀ progenitors and had corresponding decreases in lengths on inflorescences and lowest racemes. All R₁ plants of accessions 8911C and 8793 had an increase in chromosome number from2n=4x=40 to2n=5x=50. Three dwarfed R₁ plants, derived from accession 8873B, were aneuploids, two having2n=48 chromosomes and the third being a probable mixoploid with 55–58 chromosomes. Other plants of accession 8873B had the R₀ chromosome number. Fertility, as estimated by pollen stainability and seed set, generally was reduced in R₁ plants relative to the R₀. This reduction was not drastic, however, with all flowering plants having 45% or higher seed set. Apomixis apparently maintained fertility in all R₁ plants, including those with a pentaploid chromosome number. All R₁ plants differed from their respective R₀ plants in peroxidase and esterase banding patterns. All R₁ plants of accessions 8911C, and 8793, respectively, had identical peroxidase and esterase bands. For both enzyme systems two banding patterns were present in R₁ plants of accession 8873B, with 12 of 13 plants exhibiting common patterns. Examination of R₂ progeny plants confirmed the genetic transmission of the variant phenotypes and, by virtue of uniformity, indicated apomictic reproduction in the R₁ plants. The results demonstrate the production of potentially useful genetic and cytogenetic variant plants via tissue culture in these apomictic species.     

The time and duration of the premeiotic inteprhase in microsporocytes ofTrillium kamtschaticum

The time and duration of each phase of the premeiotic interphase were determined in microsporocytes of two clones (S and K clones) ofTrillium kamtschaticum. After collectionTrillium plants were stored at 3 C or 7 C prior to completion of premeiotic mitosis in archesporial cells. For autoradiography, cells were explanted in the presence of³H-thymidine to identify the interval of the premeiotic DNA synthesis. Approximate durations of the G₁, S and G₂ phases for the K clone stored at 3 C were estimated to be 12, 12 and 14 days, respectively. The interval of premeiotic development was markedly different between clones. A high degree of synchrony in meiotic development, which is usually observed within anthers up to late meiotic prophase, was confirmed at the S phase, suggesting that synchrony is established during the G₁ interval.     

Trade-off relationships between some reproductive characteristics in plants with special reference to life history stragegy

Several reproductive triats in plants were studied in more than 200 populations of 61 wild species from diverse ecological conditions. As a result, it was found that there occur three distinct types of plants in the energy allocation patterns to reproductive structures (RA) and the propagule output per plant (P_N), i.e. (1) the number of propagules per plant increases in response to the increase in RA (Type I), (2) the number of propagules decreases in response to the increase in RA (Type II), and (3) the RA remains constant despite the great differences in the propagule number per plant. A conspicuous trade-off relationship was also discovered to occur between the RA to a single propagule (R_A) and the propagule output per plant (P_N), such that log R_A=logC−blot P_N, or R_A=C/P_N ^b =CP_N ^−b , where C is a constant. The three different ranges ofb-values were recognized, i.e.b<1.0,b>1.0, andb=1.0, which correspond to Type I, Type II, and Type III, respectively. Related problems to the concept ofr- andK-strategy are also discussed.     

<Emphasis Type="Italic">Agrobacterium</Emphasis>-mediated transformation of Perilla (<Emphasis Type="Italic">Perilla frutescens</Emphasis>)

Agrobacterium tumefaciens-mediated transformation system for perilla (Perilla frutescens Britt) was developed. Agrobacterium strain EHA105 harboring binary vector pBK I containing bar and γ-tmt cassettes or pIG121Hm containing nptII, hpt, and gusA cassettes were used for transformation. Three different types of explant, hypocotyl, cotyledon and leaf, were evaluated for transformation and hypocotyl explants resulted in the highest transformation efficiency with an average of 3.1 and 2.2%, with pBK I and pIG121Hm, respectively. The Perilla spp. displayed genotype-response for transformation. The effective concentrations of selective agents were 2 mg l⁻¹ phosphinothricin (PPT) and 150 mg l⁻¹ kanamycin, respectively, for shoot induction and 1 mg l⁻¹ PPT and 125 mg l⁻¹ kanamycin, respectively, for shoot elongation. The transformation events were confirmed by herbicide Basta spray or histochemical GUS staining of T₀ and T₁ plants. The T-DNA integration and transgene inheritance were confirmed by PCR and Southern blot analysis of random samples of T₀ and T₁ transgenic plants.     

The detection of picomolar quantities of GD1b,GT1b and GQ1b on thin-layer chromatograms by the direct binding of125I-labeled tetanus toxin,fragment C

The¹²⁵I-labeled fragment C of tetanus toxin was found to bind specifically to the gangliosides G_D1b, G_T1b, and G_Q1b when applied to thin-layer chromatograms on which a mixture of gangliosides had been resolved. As little as 2.5 pmoles of these gangliosides could be detected by this method. In addition to factors determined by the sample, namely the amount and species of gangliosides present, optimal binding of the¹²⁵I-labeled fragment C also depended upon the iodination procedure used to generate the probe, the toxin concentration, and the concentration, buffer type, pH, and ionic strength of the binding solution. This new technique was shown to be a sensitive method for the detection and identification of specific gangliosides originating from extraneural or neural cells.Nomenclature: The gangliosides follow the nomenclature system of Svennerholm [Eur J Biochem (1977) 79:11–21] G_M3 II³NeuAc-LacCer - G_D3 II³(NeuAc)₂-LacCer - G_M1 II³NeuAc-GgOse₄Cer - G_D1a IV³NeuAc, II³NeuAc-GgOse₄Cer - G_D1b II³(NeuAc)₂-GgOse₄Cer - G_T1b IV³NeuAc, II³(NeuAc)²-GgOse₄Cer - G_Q1b IV³(Neu-Ac)₂, II³(NeuAc)₂-GgOse₄Cer - G_P1b IV³(NeuAc)₃, II³(NeuAc)₂-GgOse₄Cer     

Screening for grain polyphenol variants from high-tannin sorghum somaclones

Several hundred somaclones established from plants regenerated from embryogenic callus cultures of six high tannin sorghum lines were screened for variants with altered levels of polyphenols in the grain. Grain from over 6000 plants including the R ₁ (primary), R₂, and R₃ generations were analyzed for total phenols, flavan-4-ols, and proanthocyanidins (condensed tannins). Although many variants which had lost the ability to synthesize chlorophyll were found, none of the somaclones tested had lost or greatly reduced the ability to synthesize any of the polyphenols assayed. However, we did observe statistically significant differences in polyphenol concentration between tissue culture-derived R₁ plants and the parental controls. In the R₂ generation the proportion of somaclones which differed significantly from the parents varied from 47% to 68% depending upon genotype. The average somaclonal variation rate and somaclonal variant frequency estimated in the tested population for the three polyphenol characteristics ranged from 37.3% to 40.7% and 5.3% to 7.8%, respectively. Variants with decreased levels of polyphenols were usually epigenetic and reverted back to normal levels in subsequent generations, but those with increased levels usually persisted after two meiotic cycles, indicating they are heritable. Variants with polyphenol levels increased up to 80% or decreased by 30% were selected for in the R₃ generation.     

遮阴对高山杜鹃叶片解剖和光合特性的影响

为了解高山杜鹃对光能的需求和适应性,该研究以盆栽3 a生高山杜鹃品种cv. Furnivall's Daughter为材料,探讨了遮阴对高山杜鹃叶片解剖结构和光合特性的影响。结果表明:光照强度对高山杜鹃品种cv. Furnivall's Daughter叶片的气孔密度没有显著影响,其气孔密度范围在299.70~327.22个·mm~(-2)之间,但光照对气孔开度和单个气孔器的面积影响显著,100%全光照和30%全光照处理植株分别具有最小和最大的叶片气孔开度。在处理的光强范围内,随着光强减弱,叶片厚度、栅栏组织厚度、海绵组织厚度以及上、下表皮厚度逐渐降低,有利于提高叶片的光能利用效率。100%全光照处理下,高山杜鹃叶片的光饱和点(LSP)、净光合速率(P_n)、饱和光合速率(P_(max))、气孔导度(Gs)、蒸腾速率(Tr)均较低,遮阴处理有效提高了Pn、P_(max)、G_s、T_r和光能利用效率(LUE),且30%全光照处理植株的叶片光补偿点(LCP)、暗呼吸速率(Rd)最低,而LSP、P_n、P_(max)、G_s、T_r和LUE最高。这表明高山杜鹃在云南昆明地区的最适光照条件是30%左右的全光照,在高山杜鹃的栽培及应用中,应采取适当的遮阴措施以满足其生长的最佳光照条件。     

Evaluation of the mycological status of luncheon meat with special reference to aflatoxigenic moulds and aflatoxin residues

The luncheon meat samples analyzed, which were produced locally by the two main luncheon meat producing companies in Egypt were relatively highly contaminated either by moulds and yeasts in general, aflatoxigenic species and aflatoxin residues in particular. The most frequently encountered fungi from the samples were yeasts, Aspergillus niger, A. flavus, Penicillium chrysogenum, Rhizopus stolonifer, Mucor circinelloides. Less common were Cladosporium sphaerospermum, Alternaria alternata, Mycosphaerella tassiana, P. aurantiogriseum and P. oxalicum. The most important aflatoxigenic species, A. flavus, was isolated frequently. It was 10% of the total fungal isolates from both samples of the two companies. Seven luncheon meat samples out of 50 analyzed were positive for aflatoxin B₁ or B₁ and G₁, while all samples were negative for aflatoxins B₂, G₂, M₁ and M₂. Aflatoxin B₁ was detected only in 4 and 3 samples out of 25 analyzed from each of company A and B, respectively. The highest detectable level, 11.1 ppb, was recorded in a sample from company B and the least, 0.5 ppb, in a sample from company A. Aflatoxin G₁, at concentration of 3.2 ppb, was detected in only one sample of the aflatoxin B₁ – contaminated 3 samples of company B: this sample also had the highest level of aflatoxin B₁. Some luncheon meat samples had higher numbers of aflatoxigenic A. flavus than others, however these samples were negative for aflatoxins. The hazardous potential of such contamination will be discussed. This revised version was published online in June 2006 with corrections to the Cover Date.     

Antioxidant Enzyme Isoforms on Gels in Two Poplar Clones Differing in Sensitivity After Exposure to Ozone

The effect of acute ozone (O₃) fumigation on isozyme patterns of superoxide dismutase (SOD), peroxidase (POD) and ascorbate peroxidase (APX) in mature (ML) and young leaves (YL) of two poplar clones, contrasting in O₃-sensitivity was analysed. Untreated leaves of both the O₃-sensitive (O₃-S) clone Eridano of Populus deltoides×P. maximowiczii and the O₃-resistant (O₃-R) clone I-214 of P.×euramericana showed four distinct SOD isoforms with a relative mobility (R_f) of 0.54 (MnSOD), 0.60 (Cu/ZnSOD), 0.65 (unidentified), and 0.71 (Cu/ZnSOD). After O₃-fumigation the activity of the SOD isoforms showed only quantitative variations with respect to control plants. In ML of untreated O₃-R plants seven POD isoforms (R_f= 0.13, 0.19, 0.34, 0.59, 0.64, 0.70 and 0.75) were found, while in YL one isoform (R_f= 0.34) was undetected. Only three POD isoforms in both ML and YL of untreated O₃-S plants were resolved. The electrophoretic pattern of POD in O₃-S leaves was greatly modified by acute O₃-fumigation with the appearance of new isoforms in both YL and ML and the disappearance of an isoform (R_f= 0.13) in YL. Additionally, O₃-exposure induced the appearance of two APX isoforms in YL (R_f= 0.66 and 0.70), and one isoform in ML (R_f= 0.70) of the O₃-S clone. By contrast, the activity of the three APX isoformes (R_f= 0.64, 0.70 and 0.76) detected in O₃-R leaves showed only quantitative variation with respect to untreated plants. From these data it is concluded that: 1) in these poplar hybrids antioxidant enzyme activity is developmentally regulated and greatly affected by acute O₃ stress treatments and 2) the different enzymes activity displayed by the two poplar clones, especially for POD and APX isoformes, could partly explain their distinct O₃-sensitivity.     

Selection of somaclonal variants with low-temperature germinability in melon (Cucumis melo L.)

Summary Plants were regenerated from adventitious buds and somatic embryos (R₀) of melon (Cucumis melo L.), the cultivar Andes. Somaclonal variants of melon with low temperature germinability were selected from the progenies (R₁) of R₀ plants. Among 5,618 R₁ seeds harvested from 23 R₀ plants that were regenerated from adventitious buds 4 seeds germinated after 5 days of culture at 15 °C (selection rate; 0.07%). However, among 374 R₂ seeds harvested from 2 R₁ plants no seed germinated after 7 days of culture at 14 °C. Among 9,181 R₁ seeds harvested from 50 R₀ plants regenerated from somatic embryos 110 seeds germinated after 5 days of culture at 15 °C (selection rate; 1.20%). Among 3,717 R₂ seeds harvested from 17 R₁ plants 113 seeds germinated after 7 days of culture at 14 °C (selection rate; 3.04%). R₃ seeds were collected from these R₂ plants following self-pollination. Forty-five of the 47 lines (R₃) originated from 10 R₀ plants showed higher germination rates than that of the original cultivar. Selected lines with low-temperature germinability showed greater fruit growth rate than the original cultivar during the middle stage when they were cultivated in a greenhouse under low-temperature conditions. Of fruits harvested from 31 lines, 15 lines showed greater fruit volume than the original cultivar.     

Fossil bagrid catfishes from Japan and their zoogeography, with description of a new species,Pseudobagrus ikiensis

Morphological characteristics of fossil bagrid catfishes from six Miocene to Pleistocene localities in Japan are described. A new species of the Middle Miocene bagrid,Pseudobagrus ikiensis, is described, based on five nearly complete specimens (ca. 19 cm SL) and one half-body specimen from the Chojabaru Formation (15 Ma) of the Iki Group in Nagasaki Prefecture. The species is diagnosed by a unique combination of characters: 14–16 anal fin rays, 44–47 vertebrae, deeply forked caudal fin, pectoral spines with serrations on the anterior edge and supraoccipital process extending to the first pterygiophore of the dorsal fin.Pseudobagrus ikiensis is morphologically close to the extantP. fulvidraco, which is widely distributed in China, Siberia and the Korean Peninsula, suggesting that both lineages had appeared by the Middle Miocene. All other fossil specimens are from the Pliocene (3–4 Ma) Ueno Formation (lowest Kobiwako Group, Ohyamada, Mie Pref.) and Tokai Group (Tsu, Mie Pref.), and Pleistocene cave deposits (Inasa, Shizuoka Pref., Mine, Yamaguchi Pref. and Kanogawa, Ehime Pref.). These are incomplete, comprising mainly dorsal and pectoral spines. Being indistinguishable from the extantP. nudiceps, they are thus considered to be included in that lineage. Although the geological distribution of these Plio-Pleistocene fossils nearly overlaps that of the extantP. nudiceps (west of the Suzuka Mountains), fossil specimens have also been found in the Ise Bay area (Tsu), whereP. ichikawai is the only extant bagrid, and further east (Inasa). Based on evidence that the latter is not a sister species ofP. nudiceps, the distribution of the fossils indicates that the range ofP. nudiceps was restricted to west of the Suzuka Mts. during the Pleistocene or Holocene.     

Patterns of genetic diversity and differentiation in the tsetse fly <Emphasis Type="Italic">Glossina morsitans morsitans</Emphasis> Westwood populations in East and southern Africa

Genetic diversity and differentiation within and among nine G. morsitans morsitans populations from East and southern Africa was assessed by examining variation at seven microsatellite loci and a mitochondrial locus, cytochrome oxidase (COI). Mean COI diversity within populations was 0.63 ± 0.33 and 0.81 taken over all populations. Diversities averaged over microsatellite loci were high (mean number of alleles/locus ≥7.4; mean H _E ≥ 65%) in all populations. Diversities averaged across populations were greater in East Africa (mean number of alleles = 22 ± 2.6; mean h _e = 0.773 ± 0.033) than in southern Africa (mean number of alleles = 18.7 ± 4.0; mean h _e = 0.713 ± 0.072). Differentiation among all populations was highly significant (R _ST = 0.25, F _ST = 0.132). Nei’s G _ij statistics were 0.09 and 0.19 within regions for microsatellites and mitochondria, respectively; between regions, G _ij was 0.14 for microsatellites and 0.23 for mitochondria. G _ST among populations was 0.23 for microsatellite loci and 0.40 for mitochondria. The F, G and R statistics indicate highly restricted gene flow among G. m. morsitans populations separated over geographic scales of 12–917 km.     

Number of floral organs in Circaeaster agrestis (Circaeasteraceae) and possible homeosis among floral organs

98.9% of 5092 flowers from 1041 individuals of Circaeaster agrestis have five floral organs, the formula is P₃A₁G₁ (73.13%), P₂A₂G₁ (25.59%), and P₂A₁G₂ (0.22%). Only 0.4% of the flowers have six floral organs and the formula is P₃A₁G₂ (20 flowers) or P₃A₂G₁ (one flower). All these flowers have one vascular bundle in the pedicel and were considered to be normal ones. There are 33 flowers (0.65%) with six or more floral organs and two vascular bundles in the pedicel and we found traces of fusion of different degree of two flowers into one. These flowers were considered as abnormal. Therefore the normal number of floral organs of C. agrestis is five and occasionally six, and the floral formulas are P₃A₁G₁ or P₂A₂G₁, sometimes P₂A₁G₂, and occasionally P₃A₁G₂ or P₃A₂G₁. A tepal in P₃A₁G₁ may be replaced by a stamen in P₂A₂G₁ or by a carpel in P₂A₁G₂ or in reverse. A carpel in P₃A₁G₂ may be replaced by a stamen in P₃A₂G₁ or in reverse. We hypothesize that there are two possibilities for the number of the floral organs to be five (six), the result of reduction from P₃A₂G₂, or there exists homeosis among floral organs.