ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1995.tb00764.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SUMMARYThe distribution of calmodulin was studied during somatic and zygotic embryogenesis and during germination of carrot. Calmodulin levels were visualized by immunofluorescence, using semi‐thin sections of different developmental stages of embryogenesis. In proembryogenic masses the distribution of calmodulin was highly variable between individual cells. In later stages of somatic embryogenesis, calmodulin was mainly found associated with organelles in the protoderm. In contrast, in zygotic embryos calmodulin was found to be evenly distributed over the entire embryo. A polarized distribution of calmodulin was observed during germination of the zygotic embryos. Calmodulin was mainly found in the cytoplasm of the epidermis of the cotyledons and the hypocotyl, but was clearly associated with organelles in the root side of the germling. It is concluded that the distribution of calmodulin differs in somatic and zygotic embryos of carrot and that the distribution in somatic embryos resembles the distribution in germinating zygotic embryo

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1995.tb00765.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SUMMARYWe have examined the effects of environmental conditions on the sprouting of micropropagated bulblets ofLilium speciosumwith various levels of dormancy. After planting at low temperature (15°C) orin vitro, a higher percentage of bulblets sprouted than after planting at high temperature (20 or 25°C) or in soil. Dormancy was relative, i.e. bulblets with deep dormancy were capable of sprouting at a limited range of conditions and bulblets with low or no dormancy at a wide range. The promotive effect of thein vitrocultivation was, to a large extent, caused by exposure of the bulblets to light which was absent after planting in soil because of coverage by a layer of soi

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1995.tb00766.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SUMMARYThe development fruits (nutlets) and seeds ofSchoenus nigricans, a perennial sedge of wet coastal dune slacks, was compared between populations of the Mediterranean Sea and the North Sea, to examine the hypothesis of adaptation in a geographical gradient (Baker 1972). The development period of nutlets and seeds lasted several months. The serial insertion of nutlets on the spikelet caused a negative mass gradient from adaxial to abaxial nutlets. Final nutlet mass (first adaxial spikelet position) of Mediterranean plants was 30% higher than that of North Sea plants, extending Baker's hypothesis of the inverse relationship between seed (nutlet) mass and geographical altitude to geographical latitude.The difference in final nutlet mass between plants from populations of the Mediterranean and North Sea persisted, when plants were grown under the climatic conditions of the North Sea plants. However, the nutlet mass, but not the seed mass of the Mediterranean plants, grown under Dutch climatic conditions, was less than at their original size. Start of flowering of the Mediterranean plants under Dutch climatic conditions was delayed by 1–2 months, compared with their flowering at the Mediterranean sites. Nutlets of Mediterranean plants ripened later than those of Dutch plants under the Dutch climatic conditions.The differentiation in nutlet and seed masses and plant height in the geographic gradient in Europe and its persistence under experimental conditions indicates a strong genetic component of population differentiation. The data do not support the hypothesis of ‘general‐purpose genotypes’ (Schmid 1992) in this wet dune slack

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1995.tb00767.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SUMMARYPollination ecology and components of reproductive success ofGentiana cruciata, a rare species in The Netherlands, was studied in two dune populations (20 andc. 300 flowering individuals, respectively) during the summer of 1989.Gentiana cruciatawas fully self‐compatible, but spontaneous self‐pollination resulted in severe pollen limitation: natural pollination showed lower reproductive success as compared to hand‐pollinations. In addition, reproductive success in the small population was significantly lower through all pollination treatments. Natural pollination was carried out mainly by the bumblebeeBombus pascuorumvisiting the flowers for nectar, which was available at all floral stages but in greatest quantities during the morning hours. The number of visitors and visits to the flowers was generally high. However, the constancy of bumblebee visitors (measured as the proportion of heterospecific pollen found on bumblebees) decreased strongly in the afternoon, when nectar standing crop was relatively low. The number of visits and visitors to theG. cruciataflowers remained still very high, but the average time spent per flower decreased significantly. We argue that, in general, the low reproductive success through natural pollination is caused by pollen limitation as a consequence of competition through heterospecific pollen (mainly of the abundantly co‐flowering shrubRubus caesius)transferred and deposited on the stigmas by the bumblebees. The overall lower reproductive potential of the small population may be the result of a combination of poor site quality, rabbit grazing, and inb

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1995.tb00768.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1995.tb00769.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Book reviewed in this article:The Origin of Land PlantsLinda E. GrahamReproduction in FungiCharles G. ElliottDie Pflanzengesellschaften Österreichs Tell I: Anthropogene VegetationLadislav Mucina, Georg Grabherr and Thomas Ellmauer (eds)Tell II: Natiirliche waldfreie VegetationGeorg Grabherr and Ladislav Mucina (eds)Tell III: Wälder ond GebüscheLadislav Mucina, Georg Grabherr und Susanne Wallnofer (eds)Photosynthesis, 5th ednD.O. Hall and K.K. RaoPhotoinhibition of Photosynthesis. From Molecular Mechanisms to the FieldN.R. Baker and J.R. Bowyer (eds)Bibliography of Systematic Wood Anatomy of DicotyledonsMary GregorySurvey of English Macroscopic Bark TerminologyLeo Juni

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1995.tb00770.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1995.tb00771.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1995.tb00772.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1995.tb00763.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY