Vacuolated pinealocytes in the hedgehog (Erinaceus europaeus L.) and the mole (Talpa europaea L.)

Special cells in the hedgehog and mole pineal gland which are characterized by an enormous single vacuole were studied. The presence of secretory granules (in the hedgehog) and of paracrystalline structures (in the mole) in the cytoplasm of these cells indicates that they are pinealocytes.     

Micropropagation of hornbeam (Carpinus betulus L.) and ash (Fraxinus excelsior L.)

Shoot multiplication of hornbeam was stimulated onWPM, QL andDKW medium supplemented with a low concentration of BAP or BPA (0.1-0.2 mg I -1) andIBA (0.1 mg I -1). Low concentration of thidiazuron promoted axillary bud formation, higher concentration inhibited shoot elongation. Microshoots were rooted onWPM supplemented with a low auxin concentration (IBA or NAA 0.2-0.5 mg I -1). High rooting percentages were obtained. Shoot proliferation of ash was stimulated on MS andDKW medium supplemented withBAP orBPA (2.0-5.0 mg I -1) andIBA (0.1 mg I -1). Root formation was promoted onWPM containing a low auxin concentration. Rooted plantlets were transplanted into soil and after hardening off the micropropagated trees were planted in the field. The planted trees grew normally without showing signs of abnormality.     

扫帚菜、蕨菜营养成分分析

对扫帚菜、蕨菜两种山野菜的粗蛋白、粗脂肪、膳食纤维、胡萝卜素、氨基酸、维生素及微量元素等营养成分进行了分析.结果表明,两种山野菜营养丰富,各种营养成分较为齐全,为开发食用山野菜等绿色食品提供科学依据和参考.     

Karyotypes of Bembidion quadrimaculatum (L.) and Clivina fossor (L.) (Coleoptera: Carabidae)

Bembidion quadrimaculatum possesses 24 chromosomes: 2n male = 22 + XY, 2n female = 22 + XX; their structure is meta- and submetacentric and differences in length between them are slight. Achiasmatic meiosis has been identified in spermatogenesis. The diploid chromosome number in Clivina fossor is 44; 2n male = 42 + XY, 2n female = 42 + XX. The chromosome structure is meta-, submeta-, and subtelocentric and X is the longest element in the set. 1 to 2 chiasmata per bivalent occur in meiosis.     

Epigenetics’ Role in the Common Bean (Phaseolus vulgaris L.) and Soybean (Glycine max (L.) Merr.) Nodulation: a Review

Plant Molecular Biology Reporter - Nitrogen-fixing bacteria establish symbiosis with legumes for the biological nitrogen fixation process in specific root structures called nodules. Among these...     

Synchronization of protoplasts from Glycine max (L.) Merr. and Brassica napus (L.)

Cells of Glycine max originating in a suspension culture and cells of Brassica napus prepared from hypocotyls were synchronized. Synchronization was achieved by preparing protoplasts in the usual way and subsequently letting the protoplasts regenerate into cells by removing the cell-wall-digesting enzymes. More than 70% of the cells had divided synchronously at the end of the first cycle as determined by the mitotic index. The high frequency of mitosis critically depended on the osmolality of the medium. The duration of the S-phase was estimated by measuring the activity of thymidylate kinase as well as incorporation of [³H]deoxythymidine into acid-insoluble material. The data indicate that synchronization is induced by resetting the cell cycle.Abbreviations dTMP deoxythymidine 5-monophosphate - TCA trichloroacetic acid     

Shrinkage of flounder Platichthys flesus (L.) and turbot Psetta maxima (L.) following freezing

Freezing of adult flounder Platichthys flesus and turbot Psetta maxima for 24 h resulted in mean decrease of total length ( L _T) of 2·1 and 1·3% and a reduced body mass ( M ) of 3·1 and 1·3%, respectively. Increasing the freezing time to 25 days increased the shrinkage in turbot but not in flounder. The L _T and M _T conversion equations for the different species and time spent frozen are given. The differences between species could be explained by the higher volume to surface area relationship in turbot compared with flounder.     

Conservation of S-locus for self-incompatibility in Brassica napus (L.) and Brassica oleracea (L.)

 Self-incompatibility (SI) in Brassica is a sporophytic system, genetically determined by alleles at the S-locus, which prevents self-fertilization and encourages outbreeding. This system occurs naturally in diploid Brassica species but is introduced into amphidiploid Brassica species by interspecific breeding, so that in both cases there is a potential for yield increase due to heterosis and the combination of desirable characteristics from both parental lines. Using a polymerase chain reaction (PCR) based analysis specific for the alleles of the SLG (S-locus glycoprotein gene) located on the S-locus, we genetically mapped the S-locus of B. oleracea for SI using a F₂ population from a cross between a rapid-cycling B. oleracea line (CrGC-85) and a cabbage line (86-16-5). The linkage map contained both RFLP (restriction fragment length polymorphism) and RAPD (random amplified polymorphic DNA) markers. Similarly, the S-loci were mapped in B. napus using two different crosses (91-SN-5263×87-DHS-002; 90-DHW-1855-4×87-DHS-002) where the common male parent was self-compatible, while the S-alleles introgressed in the two different SI female parents had not been characterized. The linkage group with the S-locus in B. oleracea showed remarkable homology to the corresponding linkage group in B. napus except that in the latter there was an additional locus present, which might have been introgressed from B. rapa. The S-allele in the rapid-cycling Brassica was identified as the S₂₉ allele, the S-allele of the cabbage was the S ₅ allele. These same alleles were present in our two B. napus SI lines, but there was evidence that it might not be the active or major SI allele that caused self-incompatibility in these two B. napus crosses. Received: 7 June 1996/Accepted: 6 September 1996     

Competition for nutrients between Calluna vulgaris (L.) Hull and Molinia caerulea (L.) Moench

Summary A combination of a removal and fertilization experiment in the field and a replacement experiment in containers in a cold frame was carried out to investigate the role of nutrient supply in the interactions between Calluna vulgaris and Molinia caerulea. It is concluded that the growth of Calluna as well as that of Molinia increased with increasing nutrient availability. However, the increase in biomass of Molinia was much larger than that of Calluna. It is also concluded that increased nutrient availability favours the competitive vigour of Molinia in interaction with Calluna.     

Biodiversity of rice (Oryza sativa L.) and sugarcane (Saccharum officinarum L.) rhizosphere pseudomonads

Fluorescent pseudomonads were isolated from the rhizosphere of rice and sugarcane and examined for their biodiversity. All fifty strains of the fluorescent pseudomonads produced indole acetic acid. Among these pseudomonads, halves of sugarcane rhizosphere isolates and one isolate from the rice rhizosphere exhibited phosphate solubilization activity. On the contrary, majority of the rice rhizosphere pseudomonads, and one isolate from sugarcane rhizosphere exhibited antifungal activity. These fluorescent pseudomonads were further classified based on their growth and biochemical characteristics. Those isolates that had same biochemical characteristics were distinguished by random amplification of polymorphic DNA (RAPD). These biochemical and molecular biological methods clearly differentiated fluorescent Pseudomonads of rice and sugarcane rhizosphere.     

Experimental research on the feeding of bream (Abramis brama L.) and white bream (Blicca bjoerkna L.)

Summary The feeding efficiency (the amount of food organisms (chironomids) eaten per unit time and weight raised to the power 0.8) of bream and white bream was determined in relation to the grain size of the substrate, in which the food was presented. Sand was used as substrate with a grain size up to 1500 , divided in eight fractions. The bream used had lengths of 14 and 33 cm and the white bream had a length of 21 cm.The experiments showed quite clearly that the grain size of the substrate influenced the feeding efficiency of all these fishes. An increasing grain size resulted in an decreasing feeding efficiency, because only up to a definite grain size the substrate can be filtered through the gill rakers. If the grain size is larger, the substrate cannot be sieved and is spit out. The size at which this switch occurred was different for all the fishes. For the small bream it was 350 , for the large bream 500 , and for the white bream 600 .Comparing the feeding efficiencies for a grain size which can be sieved by all these fishes, no significant difference was found between large bream and white bream. The small bream, however, was less efficient. Probably this difference is caused by the different sucking capacities of small and large fish. The small bream cannot in one time suck in the chironomids presented at 1 cm depth, while large bream and white bream can. So both grain size and depth at which the food was presented differentially determined the feeding efficiency of these fishes.     

Aestivation in Pieris brassicae (L.) affects the parasitoid load caused by Cotesia glomerata (L.)

The large white butterfly Pieris brassicae (L.) (Lepidoptera: Pieridae) undergoes a unique aestivation in southern Spain. Its pupae remain dormant for three months in summer, emerging in early September. Its main parasitoid, Cotesia glomerata (L.) (Hymenoptera: Braconidae), shows no such diapause behavior and is thus deprived of its main host for this period and has to switch to less suitable host species. To study the effect the aestivation has on the parasitoids, caterpillars were collected from the region in May and September and levels of parasitization were determined. Results show that parasitoid attacks decrease clearly after the summer diapause. The number of parasitized butterfly clutches in September was only one third as the number in May and the infestation rate of an attacked clutch decreased by 55% after aestivation. The distribution of brood sizes of C. glomerata showed clear signs of superparasitism before but not after the diapause. Therefore, the butterfly generation after summer diapause has to deal with distinctly diminished numbers of parasitoids. This increases the survival rate of the caterpillar and thus improves the fitness of the butterfly.     

Flavonoid content in leaf extracts of the fig (Ficus carica L.), carob (Ceratonia siliqua L.) and pistachio (Pistacia lentiscus L.)

The total flavonoid content of leaf extracts (70% ethanol) from fig (Ficus carica L.), carob (Ceratonia siliqua L.) and pistachio (Pistacia lentiscus L.) plants were determined by using reverse phase high-performance liquid chromatography (HPLC)-and analyzed by UV/VIS array and electrospray ionization (ESI)-mass spectrometry (MS) detectors. As a base for comparison, flavonoid type and level were also determined in extracts from soybeans and grape seeds. It was found that the major flavonoids in Ficus are quercetin and luteolin, with a total of 631 and 681 mg/kg extract, respectively. In Ceratonia leaves, nine different flavonoids were detected. The major one was myricetin (1486 mg/kg extract), with a similar level in Pistacia (1331 mg/kg extract, myricetin). The present study is the first to report the presence of the isoflavone genistein in the Pistacia leaf, which was discovered to consist of about a third of the genistein level detected in soybean.     

Comparative cytogenetic mapping between the lima bean (Phaseolus lunatus L.) and the common bean (P. vulgaris L.)

The common bean (Phaseolus vulgaris) and lima bean (P. lunatus) are among the most important legumes in terms of direct human consumption. The present work establishes a comparative cytogenetic map of P. lunatus, using previously mapped markers from P. vulgaris, in association with analyses of heterochromatin distribution using the fluorochromes chromomycin A3 (CMA) and 4′,6-diamidino-2-phenylindole (DAPI) and localization of the 5S and 45S ribosomal DNA (rDNA) probes. Seven BACs selected from different common bean chromosomes demonstrated a repetitive pericentromeric pattern corresponding to the heterochromatic regions revealed by CMA/DAPI and could not be mapped. The subtelomeric repetitive pattern observed for BAC 63H6 in most of the chromosome ends of common bean was not detected in lima bean, indicating lack of conservation of this subtelomeric repeat. All chromosomes could be identified and 16 single-copy clones were mapped. These results showed a significant conservation of synteny between species, although change in centromere position suggested the occurrence of pericentric inversions on chromosomes 2, 9 and 10. The low number of structural rearrangements reflects the karyotypic stability of the genus.