汞离子对细基江蓠孢子萌发和生长的影响     

周银环  唐月娣  淮永丽  黄海立  赵素芬 《广东海洋大学学报》2006,26(3):36-40

研究了4种Hg2+浓度对细基江蓠果孢子和四分孢子附着、萌发和生长的影响。结果表明:与对照组相比,Hg2+抑制了果孢子附着却促进了四分孢子的附着,但0.0025 mg/L浓度与对照组的差异不显著(P>0.05),各浓度间差异显著(P<0.05);Hg2+在实验浓度范围内(0.0025、0.0050、0.0075、0.0100 mg/L)影响了孢子的正常萌发,使孢子不能正常分裂和生长,刺激了孢子脱落,并且使盘状体的形态发生变异;`Hg2+不同浓度之间也存在显著差异(P<0.05),并且Hg2+浓度越高对孢子的萌发和生长影响越大。  相似文献   

Germination of phytoplankton resting cells from surface sediments in two areas of the Southern Chinese coastal waters     

Zhao‐Hui Wang  Yong‐Hu Fu  Wei Kang  Ju‐Fang Liang  Yang‐Guang Gu  Xiao‐Liang Jiang 《Marine Ecology》2013,34(2):218-232

To understand the role of phytoplankton resting cells in the outbreak of algal blooms, particularly harmful algal blooms, surface sediments were collected monthly from April 2007 to March 2008 from two bays near the international ports in the Southern Chinese coastal waters. Sieved sediments were incubated for 20 and 40 days, and germinated vegetative cells were observed. Altogether, 97 taxa were recorded, of which 50 were diatoms and 35 dinoflagellates. Vegetative cells of cyanobacteria, chlorophytes, dictyophytes, euglenophytes, haptophytes, and raphidophytes were also observed. Centric diatoms such as Chaetoceros, Melosira, Skeletonema, and Thalassiosira dominated. Scrippsiella, Gymnodinium, and Alexandrium were common dinoflagellate taxa. Diatom spores germinated in samples from all seasons but were abundant in the autumn and winter samples. Low numbers of dinoflagellate cells germinated in the winter samples. The nanophytoplankton taxa, Gymnodinium corii and Chrysochromulina sp., which have not been recorded in the previous phytoplankton surveys, were abundant, suggesting either their new appearance in the water column or perhaps that they were overlooked in routine phytoplankton monitoring due to their small sizes. Vegetative cells of harmful or potentially harmful taxa were germinated, and some of them such as Amphidinium, Gambierdiscus, Ostreopsis, and Coolia have not previously been reported in the study area. Based on the results of the incubation of sediments from the two bays near the international ports, it is suggested that international shipping increases the risk of the introduction of new phytoplankton species and thus promotes the incidence of harmful algal blooms.  相似文献   

Effects of modified clay on cysts of <Emphasis Type="Italic">Scrippsiella trochoidea</Emphasis> for harmful algal bloom control     

王志富  俞志明  宋秀贤  曹西华  韩笑天 《中国海洋湖沼学报》2014,32(6):1373-1382

We present results on the effect of modified clay on cyst formation of Scrippsiella trochoidea in harmful algal bloom （HAB）. Modified clay （in concentration of 0, 0.1, 0.5, and 1.0 g/L） were added to cultures, and observations were made on cysts of S. trochoidea under controlled laboratory conditions. Results indicate that the removal rate of algal cells reached 97.7% at the clay concentration of 1.0 g/L. The cyst formation rate increased from 4.6% to 24.6% when the concentration of clay was increased from 0 to 1.0 g/L. Two cyst metamorphs were observed： spinal calcareous cysts and smooth noncalcareous ones. The proportion of the spinal cysts decreased from 76.9% to 24.1% when clay concentration increased from 0 to 1.0 g/L. In addition, modified clay affected cyst germination. The germination rate decreased with the increases in the clay concentrations. Non-calcareous cysts had a lower germination rate with a longer germination time. We conclude that modified clay could depress algal cell multiplication and promote formation of temporal cysts of S. trochoidea, which may help in controlling HAB outbreaks.  相似文献   

Observation of female gamete (Carpogonia) germination of Porphyra yezoensis and P. oligospermatangia     

Mei Junxue  Eei Xiuigeng  Duan Delin 《中国海洋湖沼学报》2005,23(4):414-417

Several papers have reported that part or whole leafy thallus seemingly consisting of zygotospores can give rise to both blades and conchocelis in the same culture ofPorphyra. Study on samples of wild and cultivatedPorphyra yezoensis andP. oligospermatangia were conducted to clarify the origination of the young blades in the culture. It is confirmed that single cells on the blade of both species, which normally intermixed with zygotospores, germinated into young blades. TEM and SEM observation has shown that the single cells ofPorphyra yezoensis had typical features of female gamete (carpogonia) but archeospore. Therefore, the female gametes are responsible in developing leafy thalli. This project was sponsored by the NSFC (No. C-0205-05-39770593)  相似文献   

Responses to salt stress in the halophyte Plantago crassifolia (Plantaginaceae)   总被引：1，自引：0，他引：1  

Oscar Vicente  Monica Boscaiu  Miguel ngel Naranjo  Elena Estrelles  Jos María Bells  Pilar Soriano 《Journal of Arid Environments》2004,58(4):705

General responses to salt stress have been investigated in the halophyte Plantago crassifolia. Seed germination was strongly inhibited by NaCl, although seed viability and germination capacity were not affected by salt pre-treatments. A concentration-dependent inhibition of plant growth was observed in the presence of NaCl, which was accompanied by the accumulation of Na⁺ ions in the leaves, as determined by cation exchange HPLC. A 20-fold increase of proline content in leaves was observed when plants were treated with 500 m NaCl, suggesting a protective role against high salinity stress for this amino acid, whose possible mechanism of action is discussed.  相似文献   

Plant life-form and germination in a Mexican inter-tropical desert: effects of soil water potential and temperature     

Joel Flores  Oscar Briones 《Journal of Arid Environments》2001,47(4):485

We investigated the effects of soil water potential (SWP) and temperature on seed germination of six coexisting species of an inter-tropical desert. These species include three life-forms; the shrubs Cercidium praecox andProsopis laevigata ; the columnar succulents Neobuxbaumia tetetzo and Pachycereus hollianus; and the arborescent semi-succulents Beaucarnea gracilis and Yucca periculosa. In the six species germinability increased and germination time and speed of germination (t⁵⁰) decreased as SWP decreased. The SWP treatments were 0 MPa, −0·12 MPa, −0·2 MPa, −0·41 MPa and −0·66 MPa. There was, however, a SWP threshold below which germination time and t⁵⁰increased and germinability decreased. The shrubs had the highest germinability whereas the columnar succulents had the lowest. The shrubs also had shorter germination time andt⁵⁰ than arborescent semi-succulents whereas seeds of the columnar succulents were indeterminate. In all species except P. laevigata germinability increased and the germination time and t⁵⁰decreased as temperature increased. The temperature treatments were 12°C, 20°C and 26°C. The shrubs had the shortest t⁵⁰and germination time and the highest germinability at all temperatures. Arborescent semi-succulents had the lowest germinability and longest germination time and t⁵⁰at the three temperatures treatments. Our results support the hypothesis that in desert environments different plant life-forms utilise different germination strategies to persist.  相似文献   

土壤湿度对小麦出苗及幼苗生长的影响   总被引：4，自引：0，他引：4  

王传海  申双和  郑有飞  何都良  赵晓丽 《南京气象学院学报》2002,25(5):693-697

土壤水分不适能显著影响小麦出苗及幼苗生长，表现为显著降低出苗率，减少单位面积的苗数；同时显著影响幼苗单株生长，表现为干重、叶面积下降。土壤水分不适对小麦群体的影响表现为单位面积的干重和叶面积指数（LAI）下降。采用通径分析衡量了出苗率和单株幼苗生长两因子对群体影响的大小。结果表明：单位面积干重下降主因是单株干重下降，叶面积指数下降主因是出苗率下降。土壤湿度大于17％且小于44％时，对小麦出苗及幼苗生长各项指标的影响幅度一般在20％以内，而低于17％或高于44％的土壤湿度对小麦的影响幅度急剧增加。小麦对土壤水分不适具有一定的适应性反应。  相似文献   

Dispersal and germination ofProsopis flexuosa(Fabaceae) seeds by desert mammals in Argentina     

Claudia M Campos  Ricardo A Ojeda 《Journal of Arid Environments》1997,35(4):707-714

The ‘algarrobo’Prosopis flexuosais an important food resource in the Monte Desert of Argentina. Native, domestic, and exotic mammals consume the fruit of this legume and disperse the seed through faeces. In the present study we analyse the effect that different dispersal agents (cattle, horse, European wild boar, rodents, gray fox) have on seed damage, viability, and germination. Cattle increase germination at the expense of reduced viability, whereas horses maintain viability but do not contribute to a prompt germination response. Among native mammals, the gray fox maintains seed viability without increasing germination, whereas rodents affect seed viability but enhance germination rates. The European wild boar, however, damages all of the seeds it consumes.  相似文献   

盐胁迫对西葫芦和黄瓜种子萌发影响的对比研究   总被引：35，自引：0，他引：35  

陈国雄  李定淑 《中国沙漠》1996,16(3):306-309

用不同浓度的地下盐水胁迫西葫芦和黄瓜种子萌发，观察其发芽率和萌发后幼苗生长情况，计算其发芽指数和活力指数，进行了对比分析。结果表明：西葫芦种子萌发对盐水生境的适应性比黄瓜强，西葫芦种子萌发的盐胁迫适宜值为０．６１ｇ／１００ｃｍ３，而黄瓜为０．３６ｇ／１００ｃｍ３。  相似文献   

Germination strategies of two halophytes in Salt Desert of northwestern China   总被引：1，自引：0，他引：1  

LI Li  ZHANG XiMing 《中国科学D辑(英文版)》2007,50(Z1):115-121

The effects of temperatures and salinities on germination of two halophytes, Kalidium capsicum and Suaeda physophora in northwestern China, were tested, and their seed size and seed production were compared. It was found that seed of Suaeda physophora germinate under 10℃, even about 0℃, and at a wide temperature range of 10―30℃. It showed about 50% germination in the concentration up to 0.7 mol/L NaCl; optimum germination temperature of Kalidium capsicum was between 20℃ and 30℃. The concentration of less than 0.3 mol/L NaCl inhibited absolutely its germination. Germination recovery was observed when salinities were reduced and total germination percentage exceeded 90%. Seeds of Kalidium capsicum showed no loss of viability while Suaeda physophora an annual loss of viability of 75% at room temperature. Mean weight of seeds of Suaeda physophora was about 8.5 times of Kalidium capsicum, whereas the number of seeds of the latter was more than 20 times of the former. Suaeda physophora was observed to be dependent on periodic precipitation in germination and seedling growth. It suggests the evident trace of the species with zonation pattern. On the other hand, the germination of Kalidium capsicum was affected by unpredictable rain and inundation. This species might be a type without zonation patterns in halophytes. It was concluded that both species are halophytes, but they are established successfully by different adaptation strategies in the early stage of life history.  相似文献