Micropropagation of sour cherry (Prunus cerasus L.) cv. Šumadinka

Sour cherry cv. umadinka (Prunus cerasus L.) is the leading Yugoslav cultivar for production orchards. A method of micropropagation has been developed for the purpose of growing umadinka on its own roots and for rapid multiplication.Aseptic cultures were initiated from shoot explants 1–2 mm long on Murashige & Skoog medium with (in mgl^-1) 6-benzylaminopurine (BAP): 1, indole-3-yl butyric acid (IBA): 1 and gibberellic acid (GA₃): 0–1.The best medium for proliferation was MS with (in mgl^-1): BAP 0.5, IBA 0.1, GA₃ 0.1, but media with (in mgl^-1): BAP 0.5, NAA 0.1, GA₃ 0.1 and BAP 1, NAA 0.1 and GA₃ 0.1 were also shown to be good. A higher degree of proliferation obtained with some media did not necessarily result in a better quality of plantlets produced.For rooting the best combination of culture medium was achieved with pretreatment 10 days in MS 1/2 with 1 mgl^-1 IBA, followed by transfer to a hormone-free medium after 5–10 days, resulting in 88% success.The rooted plants were planted in containers and acclimatized under mist, with over 90% of plants surviving transplantation.     

Net photosynthetic rate of sour cherry (Prunus cerasus L. ‘Montmorency’) during the growing season with particular reference to fruiting

Diurnal and seasonal net photosynthetic rates (Pn) of sour cherry were determined. Leaf Pn was not significantly affected by shoot excision. Under constant environmental conditions (PFD, 1200 mol m^-2 s^-1; temp. 25; relative humidity, 80–90%) there was no significant diurnal fluctuation in Pn for individual leaves. However, there was a pronounced fluctuation in Pn for whole trees measured under constant temperature but natural variation in sunlight from sunrise to sunset. Maximum Pn occurred before solar noon, remained constant for 1–2 hr, then declined. Photosynthetic rate of recently expanded leaves fluctuated through out the season but, in general, was greatest in the spring as leaves expanded, reached a peak, remained stable for several weeks, then gradually declined. The Pn of leaves on terminal shoots was not significantly different from the Pn of leaves on spurs of the same physiological age. The presence of fruit did not have a consistent effect on the Pn of sour cherry leaves.Michigan Agricultural Experiment Station Journal Article No. 10739.     

Net photosynthetic rate of sour cherry (Prunus cerasus L. ‘Montmorency’) during the growing season with particular reference to fruiting

Diurnal and seasonal net photosynthetic rates (Pn) of sour cherry were determined. Leaf Pn was not significantly affected by shoot excision. Under constant environmental conditions (PFD, 1200 μmol m^-2s^-1; temp. 25; relative humidity, 80–90%) there was no significant diurnal fluctuation in Pn for individual leaves. However, there was a pronounced fluctuation in Pn for whole trees measured under constant temperature but natural variation in sunlight from sunrise to sunset. Maximum Pn occurred before solar noon, remained constant for 1–2 hr, then declined. Photosynthetic rate of recently expanded leaves fluctuated through out the season but, in general, was greatest in the spring as leaves expanded, reached a peak, remained stable for several weeks, then gradually declined. The Pn of leaves on terminal shoots was not significantly different from the Pn of leaves on spurs of the same physiological age. The presence of fruit did not have a consistent effect on the Pn of sour cherry leaves.     

Comparative Analysis of Growth and Photosynthetic Characteristics of (Populus simonii × P. nigra) × (P. nigra × P. simonii) Hybrid Clones of Different Ploidides

To evaluate differences among poplar clones of various ploidies, 12 hybrid poplar clones (P. simonii × P. nigra) × (P. nigra × P. simonii) with different ploidies were used to study phenotypic variation in growth traits and photosynthetic characteristics. Analysis of variance showed remarkable differences for each of the investigated traits among these clones (P < 0.01). Coefficients of phenotypic variation (PCV) ranged from 2.38% to 56.71%, and repeatability ranged from 0.656 to 0.987. The Pn (photosynthetic rate) photosynthetic photon flux density (PPFD) curves of the 12 clones were S-shaped, but the Pn-ambient CO₂ (Ca) curves were shaped like an inverted “V”. The stomatal conductance (Gs)-PPFD and transpiration rate (Tr)-PPFD curves had an upward tendency; however, with increasing PFFD, the intercellular CO₂ concentration (Ci)-PPFD curves had a downward tendency in all of the clones. The Pn-PPFD and Pn-Ca curves followed the pattern of a quadratic equation. The average light saturation point and light compensation point of the triploid clones were the highest and lowest, respectively, among the three types of clones. For Pn-Ca curves, diploid clones had a higher average CO₂ saturation point and average CO₂ compensation point compared with triploid and tetraploid clones. Correlation analyses indicated that all investigated traits were strongly correlated with each other. In future studies, molecular methods should be used to analyze poplar clones of different ploidies to improve our understanding of the growth and development mechanisms of polyploidy.     

Successful hybridisation of normally incompatible hybrid aspen (Populus tremula?��?P. tremuloides) and eastern cottonwood (P. deltoides)

Hybrid aspen (Populus tremula × P. tremuloides) belong to the section Populus. Eastern cottonwood (P. deltoides) is a member of the section Aigeiros within the genus Populus. These poplar sections are generally considered to be incompatible. Here, we describe successful hybridisation between these parents, producing an offspring family with 27 individuals. The hybrid character of individuals was proven by genotypes at 16 nuclear microsatellite loci. One individual was suspected to have more than the diploid chromosome number of 2n = 38 due to the observation of more than two alleles at several loci. This individual is a triploid, ascertained by flow cytometry. Two distinct growth classes of tall and dwarf plants were observed in the progeny, reflecting different degrees of postzygotic incompatibility. Two loci linked to the tested microsatellites have an effect on height growth. Some fast-growing individuals were micropropagated to test them for biomass performance together with other clones in field trials.     

A cherry map from the inter-specific cross Prunus avium ‘Napoleon’ × P. nipponica based on microsatellite, gene-specific and isoenzyme markers

One hundred and sixty microsatellite (simple sequence repeat (SSR)) and six gene-specific markers revealing 174 loci were scored in 94 seedlings from the inter-specific cross of Prunus avium ‘Napoleon’ × Prunus nipponica accession F1292. The co-segregation data from these markers were used to construct a linkage map for cherry which spanned 680 cM over eight linkage groups with an average marker spacing of 3.9 cM per marker and just six gaps longer than 15 cM. Markers previously mapped in Prunus dulcis ‘Texas’ × Prunus persica ‘Earlygold’ allowed the cherry map to be anchored to the peach × almond map and showed the high level of synteny between the species. Eighty-four loci segregated in P. avium ‘Napoleon’ versus 159 in P. nipponica. The segregations of 32 isoenzyme loci in a subset of 47 seedlings from the progeny were scored, using polyacrylamide gel electrophoresis and/or isoelectric focusing separation followed by activity staining, and the co-segregation data were analysed along with those for 39 isoenzymes reported previously and for the 174 sequence-tagged site loci plus an additional two SSR loci. The second map incorporates 233 loci and spans 736 cM over eight linkage groups with an average marker spacing of 3.2 cM per marker and just two gaps greater than 15 cM. The microsatellite map will provide a useful tool for cherry breeding and marker-assisted selection and for synteny studies within Prunus; the gene-specific markers and isoenzymes will be useful for comparisons with maps of other rosaceous fruit crops. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

污水中草履虫P.aurelia和P.caudatum的有性过程

差不多整整一百年前,Maupus在为原生动物生物学建立的基础工作中,曾对纤毛虫的衰老问题做过大量的研究。他观察到在有控制的生长条件下培养的纤毛虫,最终衰败,即经过几百代的植物性繁殖后死亡。     

污水中草履虫P.aurelia和P.caudatum的有性过程

差不多整整一百年前,Maupus在为原生动物生物学建立的基础工作中,曾对纤毛虫的衰老问题做过大量的研究。他观察到在有控制的生长条件下培养的纤毛虫,最终衰败,即经过几百代的植物性繁殖后死亡。     

Differentiation of F1 hybrids P. nigra J. F. Arnold × P. sylvestris L., P. nigra J. F. Arnold × P. densiflora Siebold et Zucc., P. nigra J. F. Arnold × P. thunbergiana Franco and their parental species by needle volatile composition

The volatile composition of needles from three F₁ hard pine hybrids produced by the controlled hybridization and their parental species were researched with gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) in order to explore the utility of terpenes in hybrid identification (their differentiation from the parental species) as well as confirmation of hybridity. The analysed hybrids were: 1. Pinus nigra J. F. Arnold × Pinus sylvestris L. (= nisy), 2. P. nigra × Pinus densiflora Siebold et Zucc. (= nide) and 3. P. nigra × Pinus thunbergiana Franco (= nith). A total of 55 compounds were identified. All identified compounds were terpenes, except trans-2-hexenal.Three analysed F₁ hybrids showed the same qualitative pattern of the needle volatile composition as their parental species. However, there were quantitative differences in several major terpenes. The volatile composition of the needles from the hybrids nisy were equally similar to both parents, the hybrids nide were more similar to the female parent (P. nigra), whereas the hybrids nith were more similar to the male parent (P. thunbergiana). According to the content of germacrene D, as the specific component of P. nigra (female parent of the three analysed F₁ hybrids), all hybrids were intermediary in relation to the parental species. The content of Δ-3-carene (the specific component of P. sylvestris) in the hybrids nisy was also intermediary. The hybrids nide had a higher content of thunbergol (specific component of P. densiflora) than the other analysed hybrids. In view of the content of β-pinene, the specific component of P. thunbergiana, the hybrids nith were intermediary to the parental species and that content was considerably higher than in the other analysed hybrids. The intermediary quality of F₁ hybrids for these specific components in relation to the parental species confirms their hybrid character.The needle volatile composition analysis as well as the previous morphometric analysis confirm the hybrid character of three F₁ hybrids, whose female parent is P. nigra, and male parents are P. sylvestris, P. densiflora, i.e. P. thunbergiana.     

Pollen-pistil interactions in Populus: β-galactosidase activity associated with pollen-tube growth in the crosses P. nigra x P. nigra and P. nigra x P. alba

Summary In order to understand the nature of interspecific barriers in Populus, we have explored pollen/pistil interactions in intra- and interspecific crosses Populus nigra x P. nigra and P. nigra x P. alba. The kinetics of pollen-tube growth demonstrated that P. nigra and P. alba pollen tubes have distinct behavioral patterns inside P. nigra pistils. P. alba pollen tubes exhibit an unique S-shaped growth curve and an arrested growth site near the sylodium. P. nigra pollen tubes exhibit two growth phases, in the stigmatic tissues and in the ovarian cavity respectively. P. nigra and P. alba curves diverge 5 h after controlled pollination and could be related to a change in the physiology of the P. nigra pollen tube, which shifts from an autotrophic to a heterotrophic type of nutrition. Protein analysis of pollinated stigmatic extracts (0,6 and 20 h after pollination) revealed qualitative and quantitative differences that are related to the presence of either P. nigra or P. alba pollen tubes inside the stigmatic tissues. Increasing numbers of protein bands were detectable from 0 to 20 h after pollination only in intraspecific cross. Glycoproteins were detected, and the differences observed were dependent of the cross. -Galactosidase activity was found in pollinated stigmas, but an increase in its activity (one isozyme of pHi 4.2) between 6 h and 20 h after pollination was detected only in the intraspecific cross. This enzyme could play a role in heterotrophic pollen-tube nitrition, and its activity could be the final result of a series of interactions started by the initial pollen-stigma dialog.     

巴斯德毕赤酵母(P.pastoris)高密度发酵研究进展

高密度发酵已经成为提高毕赤酵母目的蛋白表达量的关键技术之一,而其中发酵工艺又是高密度发酵的一个重要因素。主要从巴斯德毕赤酵母遗传学特性、表达宿主菌、表达载体、外源蛋白的表达方面进行了阐述,并从毕赤酵母工程菌的选择、培养基的优化设计、发酵过程关键参数调控以及甲醇诱导等方面阐述毕赤酵母的高密度发酵。最后,提出了巴斯德毕赤酵母高密度发酵过程中存在的问题并进行展望。     

C.P.S.—Its Strengths and Weaknesses

The following, a supplement to the annual report of the Board of Trustees of California Physicians'' Service that was published in the March 1961 issue of California Medicine, was delivered at the 1961 Annual Session of the House of Delegates by Dr. John G. Morrison, chairman of the board.     

Alarmlaute europ?ischer und nordafrikanischer Tannenmeisen(Parus ater ater, P. ater atlas, P. ater ledouci) und der Schwarzschopfmeise(P. melanolophus)

Zusammenfassung Die Alarmlaute europäischer und nordafrikanischer Tannenmeisen gegen Nesträuber sind sehr verschieden (Abb. a, c). Europäische Tannenmeisen verwenden den nordafrikanischen Typ nur bei größter Erregung (eine Beobachtung an wildlebenden). Europäische Tannenmeisen und Schwarzschopfmeisen, die zusammen mit marokkanischen Tannenmeisen in einer Voliere gehalten wurden, brachten in Alarmsituationen zuerst die ihnen gemäßen Rufe und dann die der nordafrikanischen (Abb. d). Wahrscheinlich ist der afrikanische Alarmruftyp der ursprüngliche. Der stammesgeschichtlich junge Alarmruftyp der UntergattungPeriparus ging den nordafrikanischen Populationen verloren.

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Alarm calls of European and North African Coal Tits(Parus ater ater, P. ater atlas, P. ater ledouci) and Vigor's Black Crested Tit(P. melanolophus)

Summary The alarm call against nestpredators of European and North African Coal Tits are quite different (fig. a, c). European Coal Tits call like African Coal Tits only in situations of drastic excitement (one observation in the field). European Coal Tits and Vigor's Black Crested Tits, kept together with Coal Tits from Morocco in an aviary, used in alarm situations first their usual calls and then the calls of the North African subspecies (Abb. d). Apparently the African form of the alarm call is the older. The North African populations have lost the evolutionarity young form of the alarm call of the subgenusPeriparus.

     

苏联N. P. Korableva教授访沪

苏联巴赫生物化学研究所N.P.Korableva教授于1999年10月18～27日来沪访问。10月23日在中国科学院上海植物生理研究所作了《马铃薯块根的休眠和抗性》的学术报告,并与该所环境生理组和发育生理组座谈及商讨合作问题。     

Isozyme evidence for the parentage and multiple origins ofPotamogeton ×suecicus (P. pectinatus ×P. filiformis,Potamogetonaceae)

Evidence from isozyme analyses indicates thatPotamogeton ×suecicus is the hybrid betweenP. pectinatus andP. filiformis. The hybrid appears to have arisen on several occasions. The isozyme profiles of this hybrid from the Rivers Wharfe and Ure in Yorkshire, south of the present limit of distribution ofP. filiformis, suggest that each population is a single clone; these clones may be relics from the Weichselian glacial period. Populations of the putative hybrid from the Rivers Tweed and Till are notP. ×suecicus but probably haveP. vaginatus andP. pectinatus as parents. If so, this is a remarkable example of a pondweed hybrid persisting vegetatively in an area outside the distributional range of one of its parents.     

Two New Species of Pristionchus (Rhabditida: Diplogastridae): P. fissidentatus n. sp. from Nepal and La Réunion Island and P. elegans n. sp. from Japan

Pristionchus fissidentatus n. sp., isolated from soil in Nepal, and P. elegans n. sp., isolated from Phelotrupes auratus (Coleoptera: Scarabaeidae) in Japan, are described. The two new species are recognized as basal within the genus and thus occupy an important position for macroevolutionary studies that center on the model P. pacificus. Pristionchus fissidentatus n. sp. is distinguished by its unique stegostomatal morphology: in the stenostomatous form, the right subventral ridge has three prominent cusps and the left subventral sector has, in addition to a plate with two cusps, a prominent denticle slightly left of ventral; in the eurystomatous form, the right subventral stegostomatal sector shows both a tooth and a ridge with several cusps. Diagnostic of P. elegans n. sp. is the structure of the stenostomatous cheilostom, which bulges medially and is underlain by a large vacuolated ring. No eurystomatous form has been observed in P. elegans n. sp. Reproductive modes of P. fissidentatus n. sp. and P. elegans n. sp. are hermaphroditic and gonochoristic, respectively. The additional isolation of P. fissidentatus n. sp. from soil and two species of scarab beetle on La Réunion Island in the Indian Ocean suggests a broad geographic range for this species.