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101.
Lee KP  Lee DW 《Plant cell reports》2003,22(2):105-109
Regeneration via somatic embryogenesis from callus was studied in Dicentra spectabilis. To obtain somatic embryogenic callus, we cultured D. spectabilis seeds on MS basal media supplemented with various concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D). The highest percentage of embryogenic callus formation was observed on media containing 1.0 mg/l 2,4-D under dark conditions. Somatic embryogenesis was studied by transferring the callus onto MS basal medium containing different concentrations (0.0, 0.1, 0.5, 1.0, 2.0 mg/l) of KIN (kinetin) and/or BAP. Somatic embryogenesis on MS basal media with 1.0 mg/l of KIN was excellent under light conditions. Somatic embryos were rooted by transferring them to half-strength MS basal media containing 2 g/l Phytagel. About 64.2% of the somatic embryos converted to rooted plantlets, 4% showed secondary embryogenesis and 31.8% did not develop and died. Rooted plantlets showed a 46% survival rate when acclimatized ex vitro.Abbreviations BAP 6-Benzylaminopurine - 2.4-D 2,4-Dichlorophenoxyacetic acid - KIN Kinetin - SEM Scanning electron microscopyCommunicated by H. Lörz  相似文献   
102.
Thakar JD  Kunte K  Chauhan AK  Watve AV  Watve MG 《Oecologia》2003,136(4):565-570
In animal-pollinated flowers, the pollinators cannot detect the presence of nectar before entering flowers, and therefore flowers may cheat by not producing nectar. An earlier model suggested that a mixed strategy of producing nectarful and nectarless flowers would be evolutionarily stable. Here we compare nectarless flowers as a cheating strategy with three competing hypotheses namely "visit-more-flowers", "cross-pollination enhancement" and "better contact". We collected field data on 28 species of plants to test some of the differential predictions of the hypotheses. Nectarless flowers were detected in 24 out of 28 plant species. Correlations of percent nectarless flowers with floral and ecological variables support the cheater flower hypothesis. We further model the cost-benefits of cheating and show that an evolutionary stable ratio of nectarless to nectarful flowers can be reached. The equilibrium ratio is mainly decided by factors associated with pollinator density and pollinator learning.  相似文献   
103.
Abstract Male sperm whales are the basis for a commercially important whale-watching industry at Kaikoura, New Zealand. We examined the influence of whale-watching boats and aircraft over three years using observations from an independent research boat and from shore. We employed an information-theoretic approach to determine which factors were necessary to explain variation in blow interval, time at surface, and time to first click. In almost all analyses, models required the inclusion of the presence of the research boat or whale-watching boats or airplanes. The only exception was the model explaining variation in blow intervals observed from shore, which required only season. We also analyzed spatial behavior at the surface. Resident whales changed direction significantly more in the presence of whale-watching boats compared to encounters with only the research boat present. No such difference was observed for encounters with aircraft. Our results thus indicate that sperm whales off Kaikoura respond to whale-watching activities, although these changes are small and most likely not of biological importance. However, resident whales responded less to these activities compared to transient whales, possibly indicating habituation and, more importantly, the need to monitor continued activities closely.  相似文献   
104.
【背景】冠突散囊菌LYEC03是从陕西泾阳茯砖茶中分离得到的主要发酵菌株。【目的】研究冠突散囊菌LYEC03菌株的基因组信息及其发酵枇杷花产品的特性,从分子水平阐明冠突散囊菌的发酵机制。【方法】应用形态和显微形态观察、ITS序列鉴定、重测序及框架图测序对所分离的菌株LYEC03进行鉴定和基因组信息解析,采用所分离的菌株LYEC03发酵枇杷花,研究冠突散囊菌对枇杷花主要功效成分及抗氧化性能的影响。【结果】陕西泾阳茯砖茶中分离得到的主要发酵菌株LYEC03确定为冠突散囊菌。菌株LYEC03与参考基因组覆盖率高,含有丰富的纤维素酶、蛋白酶、氧化酶和脂肪酶相关基因;基因组相关整体变异较小,其中假设蛋白、碳水化合物激酶、纤维素酶家族糖基水解酶、位点2蛋白酶家族蛋白、多酚氧化酶和谷胱甘肽过氧化物酶等与菌株生长、能量代谢调节、产纤维酶、产蛋白酶和产氧化酶相关的基因发生了变异。菌株LYEC03基因组序列长度30 623 602 bp、GC含量51.70%、编码13 033个基因、编码基因占比55.74%,参与了碳水化合物代谢、氨基酸代谢、外源生物降解代谢、能量代谢、脂质代谢与萜类化合物和聚酮类化合物的...  相似文献   
105.
Dactylorhiza sambucina is a European terrestrial orchid that lacks a pollinator reward. Throughout most of its range, populations contain yellow- and purple-flowering individuals, but in western Germany, monomorphic yellow populations predominate. As elsewhere, bumblebee queens are the most important pollinators in these populations, and mean fruit set over two years was 19%, well within the range reported from dimorphic populations. Multivariate analyses of plant and population traits, including plant height, leaf number, flower number and density on the spikes, flowering population density, and nearest neighbor distance, showed that only individual plant height and population density had a unique positive effect on pollen export; female function was unrelated to height or population density. The positive effects of dense spacing of flowering conspecifics and tall size appear due to greater visual attractiveness. Good visual exposure may also explain that flowers higher up on the spikes, in spite of opening late in the season, had higher male reproductive success than early flowers.  相似文献   
106.
Since the XIX century, there is a controversy about the existence of biennial maturation of the acorns in Quercus suber L. While some authors recognised biennial cycles as an adaptation to habitats with short vegetative periods, other authors discarded the biennial pattern. Successive flowering events from spring to autumn and annual acorn ripening are proposed as an explanation of the multiple acorn crops typical of Iberian forests. To clarify this discussion, the presence of annual and biennial acorns was assessed in seven cork oak stands, covering a wide range of environmental conditions. In each stand, 100 individuals were sampled once in spring and once in autumn. Biennial acorns were observed with variable frequencies in all populations. There was a significant and positive relationship between latitude and the percentage of trees with biennial acorns within northern and central populations. On the contrary, this trend was not significant among southern populations. The hypothesis that the presence of biennial acorns in Quercus suber is related to individual female flowering phenology was confirmed in four populations located in the southwestern Iberian Peninsula. Unregarding local differences in the distribution of phenological stages anticipated trees bore significantly less biennial acorns than delayed individuals of the same stand. This result is coherent with the idea that the length of the vegetative period plays a crucial role in the frequency of annual and biennial acorn ripening patterns. The relationship between annual and biennial ripening cycles and the multiple acorn crops is discussed.  相似文献   
107.
We studied the adaptive arrangement of raceme flowers in dense and sparse habitats of Salvia nipponica. We recorded bumblebee visits and collected mature seeds to estimate outcrossing rates from allozyme genotypes. To examine the resource investment in flowering stalks, we measured their length and dry mass. We found that a greater number of open flowers in a raceme enhanced bumblebee visits and successive probings in both density plots. However, greater height of a raceme did not enhance these in plots of either density. In the high-density plot, both a greater mean number of open flowers in a raceme and a greater number of flowering racemes on a plant enhanced bumblebee visits, successive probings, and also enhanced outcrossing rate in spite of an increase in successive probings. Although the number of flowers per raceme had a greater positive effect on seed-to-ovule ratios than did the number of racemes, the number of flowers per raceme may be constrained because a longer flowering stalk needs greater buckling strength. Hence, it may be advantageous for plants in high-density plots to increase both number of flowers per raceme and number of racemes. In the low-density plot, a greater number of flowering racemes on a plant enhanced pollinator visits, but a greater mean number of open flowers in a raceme did not. Hence, it may be advantageous for plants to increase the number of racemes while keeping the numbers of flowers per raceme small. Thus, the adaptive number of flowers per raceme and number of racemes per plant may differ between high- and low-density plots.  相似文献   
108.
We deal in this paper with the concept of health smart home (HSH) designed to follow dependent people at home in order to avoid the hospitalisation, limiting hospital sojourns to short acute care or fast specific diagnostic investigations. For elderly people the project of such a HSH has been called AISLE (Apartment with Intelligent Sensors for Longevity Effectiveness). For this purpose, system having three levels of automatic measuring (1) the circadian activity, (2) the vegetative state, and (3) some state variables specific of certain organs involved in precise diseases, has been developed within the framework of a 'Health Integrated Smart Home Information System' (HIS2). HIS2 is an experimental platform for technologic development and clinical evaluation, in order to ensure the medical security and quality of life for patients who need home based medical monitoring. Location sensors are placed in each room of the HIS2, allowing the monitoring of patient's successive daily activity phases within the patient's home environment. We proceed with a sampling in an hourly schedule to detect weak variations of the nycthemeral rhythms. Based on numerous measurements, we establish a mean value with confidence limits of activity variables in normal behaviour permitting to detect for example a sudden abnormal event (like a fall) as well as a chronic pathologic activity (like a pollakiuria), allowing us to define a canonical domain within which the patient's activity is qualified to be 'predictable'. Alerts are set off if the patient's activity deviates from a predictable canonical domain. Moreover, we can follow the cardio-respiratory state by measuring the intensity of the respiratory sinusal arrhythmia in order to quantify the integrity of the bulbar vegetative system, and we finally propose to carefully watch abnormal symptoms like arterial pressure or presence of plasma proteins in the expired air flow for early detecting respectively hypertension or pulmonary oedema.  相似文献   
109.
Heterostyly rarely occurs in families with strongly zygomorphic flowers. For this reason Darwin (1877) doubted whether heterostyly would occur in the Lamiaceae and recent reviews have not reported the floral polymorphism in this family. Here we describe distyly in a rare species ofSalvia restricted to bluffs and seaward canyons on Santa Rosa Island (Santa Barbara Co., California) and northwestern Baja California (Mexico).Salvia brandegeei is morphologically distylous with populations composed of equal frequencies of long-and short-styled morphs differing reciprocally in stigma and anther position. Controlled hand pollinations demonstrated no significant differences in the seed set of self, intramorph or intermorph pollinations. Unlike most heterostylous species investigated,S. brandegeei does not possess diallelic incompatibility or ancillary polymorphisms of pollen and stigmas. We propose that the evolution of distyly inS. brandegeei may have been associated with an ecological shift to a new environment in which protandry failed to prevent increased levels of geitonogamy. Heterostyly was then selected because it increased the proficiency of cross-pollination. The origin of distyly in self-compatibleS. brandegeei is consistent with Lloyd and Webb's theoretical model for the evolution of distyly.  相似文献   
110.
The functional floral morphology of the three genera of Vivianiaceae (= Ledocarpaceae, Geraniales), Rhynchotheca, Viviania and Balbisia, is compared. Likely pollination mechanisms are inferred from morphology and field observations. The flowers of Viviania are nectariferous and apparently zoophilous with nectar as the (primary) pollinator reward. Balbisia has pollen flowers without nectaries, its showy corolla indicates that it is also zoophilous with pollen as sole pollinator reward; bees were observed as flower visitors. One taxon (B. gracilis) may be anemophilous. Rhynchotheca has flowers without petals, with large, pendulous anthers and lacks nectaries. It shows synchronous mass flowering in its natural populations and is evidently anemophilous. A comparison with other Geraniales shows that nectar flowers with small anthers are likely the ancestral condition in Vivianiaceae. This suggests that the pollen flowers with larger anthers of Balbisia and Rhynchotheca may represent an apomorphic condition. The documentation of pollen flowers and anemophily in Vivianiaceae expands the range of known floral and pollination syndromes in Geraniales.  相似文献   
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