Canadian journal of botany. Journal canadien de botanique最新文献

Female gametophyte and seed development inMusella lasiocarpa(Musaceae), a monotypic genus endemic to Southwestern China 中国西南特有单型属麝香的雌配子体和种子发育

Canadian journal of botany. Journal canadien de botanique Pub Date : 2007-10-01 DOI: 10.1139/B07-101

C. Xue, Hong Wang, Delong Li

{"title":"Female gametophyte and seed development inMusella lasiocarpa(Musaceae), a monotypic genus endemic to Southwestern China","authors":"C. Xue, Hong Wang, Delong Li","doi":"10.1139/B07-101","DOIUrl":"https://doi.org/10.1139/B07-101","url":null,"abstract":"Musella is a monotypic genus composed of a single species, Musella lasiocarpa (Franch.) C.Y. Wu ex H.W. Li, endemic to Southwestern China. The genus status of Musella remains controversial. Musella had been placed first in Musa , then in Ensete , and back to Musa before its monotypic status was recognized. Musella was reported to be extinct in the wild and maintained through cultivation only via vegetative propagation through sprouting of rhizomes. In this study, female gametophyte and seed development of Musella are described to assess its systematic position and possible reasons why the wild population is now extinct. The ovules are anatropous, bitegmic, and crassinucellar. The micropyle is formed by both integuments. The megaspore mother cell undergoes meiotic division and forms a linear megaspore triad or more rarely, a T-shaped megaspore tetrad. The chalazal megaspore develops into a Polygonum type embryo sac. A nucellar pad forms, and a hypostase differentiates. Fertilization is porogamous. Endosperm formation is of the nuclear type. The zygote degenerates and so the process by which the embryo develops, if it does, remains unclear. An operculum, micropylar collar, and chalazal chamber form in mature seeds. The storage tissue is mainly endosperm containing large, compound starch grains and some perisperm. The seed coat has lignified exotestal cells, 25–30 cell layers of sclerotic mesotestal cells, and unspecialized endotesta cells; the tegment consists of two layers of longitudinally elongated cells. The seed is inviable. After comparison with the other Musaceae s. str. taxa using embryological and botanical features, we conclude that Musella should be a distinct genus. Female sterility in Musella may be the main reason why the wild population is extinct. Based on these findings, we propose conservation strategies for this endemic species, including habitat protection as well as ex-situ conservation.","PeriodicalId":80871,"journal":{"name":"Canadian journal of botany. Journal canadien de botanique","volume":"85 1","pages":"964-975"},"PeriodicalIF":0.0,"publicationDate":"2007-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1139/B07-101","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64518557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Oxygen-depleted zones inside reproductive structures of Brassicaceae: implications for oxygen control of seed development. 芸苔科植物生殖结构内的缺氧带:对种子发育氧控制的意义。

Canadian journal of botany. Journal canadien de botanique Pub Date : 1999-10-01 DOI: 10.1139/B99-098

D. Porterfield, A. Kuang, P. Smith, M. Crispi, M. Musgrave

{"title":"Oxygen-depleted zones inside reproductive structures of Brassicaceae: implications for oxygen control of seed development.","authors":"D. Porterfield, A. Kuang, P. Smith, M. Crispi, M. Musgrave","doi":"10.1139/B99-098","DOIUrl":"https://doi.org/10.1139/B99-098","url":null,"abstract":"Growth of Arabidopsis thaliana (L.) Heynh. in decreasing oxygen partial pressures revealed a linear decrease in seed production below 15 kPa, with a complete absence of seed production at 2.5 kPa oxygen. This control of plant reproduction by oxygen had previously been attributed to an oxygen effect on the partitioning between vegetative and reproductive growth. However, plants grown in a series of decreasing oxygen concentrations produced progressively smaller embryos that had stopped developing at progressively younger stages, suggesting instead that their growth is limited by oxygen. Internal oxygen concentrations of buds, pistils, and developing siliques of Brassica rapa L. and siliques of Arabidopsis were measured using a small-diameter glass electrode that was moved into the structures using a micromanipulator. Oxygen partial pressures were found to be lowest in the developing perianth (11.1 kPa) and pistils (15.2 kPa) of the unopened buds. Pollination reduced oxygen concentration inside the pistils by 3 kPa after just 24 h. Inside Brassica silique locules, partial pressures of oxygen averaged 12.2 kPa in darkness, and increased linearly with increasing light levels to 16.2 kPa. Measurements inside Arabidopsis siliques averaged 6.1 kPa in the dark and rose to 12.2 kPa with light. Hypoxia in these microenvironments is postulated to be the point of control of plant reproduction by oxygen.","PeriodicalId":80871,"journal":{"name":"Canadian journal of botany. Journal canadien de botanique","volume":"158 1","pages":"1439-46"},"PeriodicalIF":0.0,"publicationDate":"1999-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80039631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 75

Response to stem bending in forest shrubs: stem or shoot reorientation and shoot release. 森林灌木对茎弯的响应:茎或芽的重新定向和芽的释放。

Canadian journal of botany. Journal canadien de botanique Pub Date : 1997-10-01 DOI: 10.1139/B97-876

B. Wilson

{"title":"Response to stem bending in forest shrubs: stem or shoot reorientation and shoot release.","authors":"B. Wilson","doi":"10.1139/B97-876","DOIUrl":"https://doi.org/10.1139/B97-876","url":null,"abstract":"Shrubs in the forest understory may be bent by their own weight or by overstory debris. To maintain height growth they must respond to bending by vertical growth of new shoots, reorientation of older axes, or by releasing preventitious buds to form epicormic shoots. I tested for these responses in Ilex verticillata L., Cornus amomum Mill., Gaylussacia baccata (Wang.) K. Koch, Viburnum cassinoides L., Hamamelis virginiana L., and Kalmia latifolia L. For each species, I removed potentially supporting vegetation adjacent to 20 stems, left 10 stems untreated to test for bending by self weight, and bent the remaining 10 stems to 45 degrees to simulate effects of fallen debris. Stem angles and curvatures were measured from before leaf out until just before leaf fall to detect either sagging from self weight or upward bending from tension wood action. Control stems initially leaned out of vertical and five of six species sagged further into a cantilever form. Several control stems failed and bent to the ground. Stems of H. virginiana, I. verticillata, and C. amomum formed tension wood, but only the first two species bent upward. Viburnum cassinoides, G. baccata, and K. latifolia formed no tension wood and sagged further down after being bent. Epicormic shoots formed with varying frequencies in all species except K. latifolia. Epicormic shoots were the major response in C. amomum, V. cassinoides, and G. baccata. New terminal shoots on bent stems recovered toward vertical in I. verticillata and K. latifolia. Negative gravitropic response of shoots was the only recovery mechanism for K. latifolia.","PeriodicalId":80871,"journal":{"name":"Canadian journal of botany. Journal canadien de botanique","volume":"79 1","pages":"1643-8"},"PeriodicalIF":0.0,"publicationDate":"1997-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88990455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

Coordinated cell elongation alone drives tropic bending in stems of the mushroom fruit body of Coprinus cinereus. 协调的细胞伸长单独驱动蘑菇子实体茎的热带弯曲。

Canadian journal of botany. Journal canadien de botanique Pub Date : 1997-07-01 DOI: 10.1139/B97-830

J. P. Greening, C. Sánchez, D. Moore

{"title":"Coordinated cell elongation alone drives tropic bending in stems of the mushroom fruit body of Coprinus cinereus.","authors":"J. P. Greening, C. Sánchez, D. Moore","doi":"10.1139/B97-830","DOIUrl":"https://doi.org/10.1139/B97-830","url":null,"abstract":"During tropic bending in the stem of the mushroom fruit body of Coprinus cinereus the majority of extension occurred in the upper 20-30% of the stem. By attaching inert markers to the stem, it was shown that the outer flank of the bend initially has a faster rate of extension, although the inner flank matches this growth rate later in the response. Thus bending results from differential enhancement of growth rate rather than sustained differences. Large voids, up to 85 micrometers in diameter, observed in tropically bent stems showed no significant difference in number between inner and outer flanks but are implicated in bending because of their absence from unbent stems. Such voids may prevent the propagation of cracks through the stem tissue during bending. Creases at the external and lumen surfaces were also peculiar to bent stems and could represent constrictions caused by localized accumulation of stresses. Cell morphometric analysis of transverse sections of both flanks of the bend revealed no significant differences in hyphal diameter, distribution, or populations of cell types, but cells of the outer flank were four to five times longer than those of the inner. Thus, tropic bending requires only an increase in length of pre-existing inflated hyphae in the outer flank tissue.","PeriodicalId":80871,"journal":{"name":"Canadian journal of botany. Journal canadien de botanique","volume":"96 1","pages":"1174-81"},"PeriodicalIF":0.0,"publicationDate":"1997-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76858446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 12

The role of endogenous ethylene in the expansion of Helianthus annuus leaves. 内源乙烯在向日葵叶片膨胀中的作用。

Canadian journal of botany. Journal canadien de botanique Pub Date : 1997-03-01 DOI: 10.1139/B97-054

S. H. Lee, D. M. Reid

{"title":"The role of endogenous ethylene in the expansion of Helianthus annuus leaves.","authors":"S. H. Lee, D. M. Reid","doi":"10.1139/B97-054","DOIUrl":"https://doi.org/10.1139/B97-054","url":null,"abstract":"The possible role of ethylene in leaf expansion of the primary leaves of sunflower plants (Helianthus annuus) was studied. Our lowest application of ethephon promoted expansion of primary leaves. Higher concentrations of ethephon, and a range of concentrations of 1-aminocyclopropane-1-carboxylic acid, increased endogenous ethylene concentration and caused a reduction in the area of the primary leaves. The inhibition in leaf expansion induced by ethephon and 1-aminocyclopropane-1-carboxylic acid was reversed by pretreating the plants with an inhibitor of ethylene action, namely silver thiosulphate. Treating leaves with lower concentrations of aminoethoxyvinylglycine reduced ethylene production and stimulated leaf expansion. This effect of aminoethoxyvinylglycine could be nullified by pretreating the plants with 1-aminocyclopropane-1-carboxylic acid. Treatment with silver thiosulphate enhanced leaf expansion. This indicates that endogenous ethylene normally plays a significant role in leaf expansion. Flooded and gravistimulated plants produced more ethylene and had smaller leaves. This could suggest that the increased ethylene is the main cause of the slowed leaf growth, however, only in some cases were we able to partially reverse the effect of flooding with silver thiosulphate. This indicates that there are probably many factors, in addition to increased ethylene, that inhibit leaf expansion in flooded and gravistimulated plants.","PeriodicalId":80871,"journal":{"name":"Canadian journal of botany. Journal canadien de botanique","volume":"8 1","pages":"501-8"},"PeriodicalIF":0.0,"publicationDate":"1997-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80736705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 61

[Geotropic reaction of different types of roots in Hevea brasiliensis]. [巴西橡胶树不同类型根系的地向性反应]。

Canadian journal of botany. Journal canadien de botanique Pub Date : 1996-12-01 DOI: 10.1139/B96-228

Y. Le Roux, L. Pagès

{"title":"[Geotropic reaction of different types of roots in Hevea brasiliensis].","authors":"Y. Le Roux, L. Pagès","doi":"10.1139/B96-228","DOIUrl":"https://doi.org/10.1139/B96-228","url":null,"abstract":"To describe the different types of geotropic reactions of hevea (Hevea brasiliensis), young seedlings were cultivated in root observation boxes and submitted to a double gravistimulation (90 degrees rotation of the minirhizotrons in the vertical plane). It was demonstrated that the taproot is a strongly orthogeotropic organ since it resumed rapidly its prestimulation vertical position. Morphological and morphogenetic modifications were associated with the geotropic response: reduced speed of growth coupled with a reduction of the apical diameter as well as an alteration of ramification density in the curving zone and the following one. Early secondary roots showed a somewhat reduced orthogeotropism that was weaker as the growth direction before gravistimulation was more distant from the vertical. Secondary roots of the acropetal sequence were semiplagiotropic, that is only those roots oriented upward after the gravistimulation resumed, more or less, the original direction. Tertiary roots didn't respond to the gravistimulation and therefore were ageotropic. Complementary observations conducted in large laboratory rhizotrons showed that late forming secondary roots were plagiotropic in their younger stages, thereafter loosing most of their sensitivity to gravity. Quaternary roots were ageotropic. On the basis of these data, a geotropic gradient was defined within the hevea root system, where the strongly responding taproot and late secondary roots are opposed to the weakly or nonresponding tertiary and quaternary roots. Functional significations of the differential geotropic reactions in different hevea root types are discussed.","PeriodicalId":80871,"journal":{"name":"Canadian journal of botany. Journal canadien de botanique","volume":"274 1","pages":"1910-8"},"PeriodicalIF":0.0,"publicationDate":"1996-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86596371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Caulonemal gravitropism and amyloplast sedimentation in the moss Funaria. 蕨类苔藓的茎部向地性和淀粉体沉积。

Canadian journal of botany. Journal canadien de botanique Pub Date : 1995-01-01 DOI: 10.1139/B95-112

J. Schwuchow, D. Kim, F. Sack

引用次数: 26

Effects of inversion on plastid position and gravitropism in Ceratodon protonemata. 倒置对角毛龙原体质体位置和向地性的影响。

Canadian journal of botany. Journal canadien de botanique Pub Date : 1993-01-01 DOI: 10.1139/B93-147

J. Schwuchow, F. Sack

{"title":"Effects of inversion on plastid position and gravitropism in Ceratodon protonemata.","authors":"J. Schwuchow, F. Sack","doi":"10.1139/B93-147","DOIUrl":"https://doi.org/10.1139/B93-147","url":null,"abstract":"When dark-grown tip cells of protonemata of the moss Ceratodon purpureus are turned to the horizontal, plastids first sediment towards gravity in a specific zone and then the tip curves upward. To determine whether gravitropism and plastid sedimentation occur in other orientations, protonemata were reoriented to angles other than 90 degrees. Qualitative and quantitative light microscopic observations show that plastid sedimentation along the cell axis occurs in both upright and inverted cells. However, only some plastids fall and sedimentation is incomplete; plastids remain distributed throughout the length of the cell, and those plastids that sediment do not fall all the way to the bottom of the cell. Tip cells are gravitropic regardless of stimulation angle, and as in higher plants, the maximal rate of initial curvature is in response to a 120 degrees reorientation. Infrared videomicroscopy, time-lapse studies of living, inverted protonemata indicate that amyloplast sedimentation precedes upward curvature. Together, these data further support (i) the hypothesis that amyloplast sedimentation functions in gravitropic sensing in these cells, and (ii) the idea that gravity affected the evolution of cell organization.","PeriodicalId":80871,"journal":{"name":"Canadian journal of botany. Journal canadien de botanique","volume":"236 2 1","pages":"1243-8"},"PeriodicalIF":0.0,"publicationDate":"1993-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85657262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 17

Recovery of gravitropism after basipetal centrifugation in protonemata of the moss Ceratodon purpureus. 紫角藓原体基底离心后向地性恢复。

Canadian journal of botany. Journal canadien de botanique Pub Date : 1991-08-01 DOI: 10.1139/B91-221

L. Walker, F. Sack

{"title":"Recovery of gravitropism after basipetal centrifugation in protonemata of the moss Ceratodon purpureus.","authors":"L. Walker, F. Sack","doi":"10.1139/B91-221","DOIUrl":"https://doi.org/10.1139/B91-221","url":null,"abstract":"Apical cells of 5-day-old dark-grown protonemata of the moss Ceratodon purpureus (Hedw.) Brid. are negatively gravitropic and appear to utilize amyloplasts as statoliths. These cells exhibit a characteristic plastid zonation (five zones) with one zone (No. 3) specialized for the lateral sedimentation of amyloplasts. Basipetal centrifugation displaces all amyloplasts in the apical cell to the end wall. In basipetally centrifuged protonemata observed using infrared videomicroscopy, tip extension occurred with or without amyloplasts present in the apical dome. The initial return of upward curvature was always correlated with the return and sedimentation of amyloplasts in zone 3. Subsequent vigorous upward curvature was correlated with distinct amyloplast zonation and further sedimentation in zone 3. Initial downward (\"wrong way\") curvature, which often preceded upward curvature, correlated with the presence of amyloplasts in the apical dome (zone 1). These data support the hypotheses that nonsedimenting amyloplasts in zone 1 are necessary for initial downward curvature and that amyloplast sedimentation in zone 3 is necessary for upward curvature.","PeriodicalId":80871,"journal":{"name":"Canadian journal of botany. Journal canadien de botanique","volume":"23 1","pages":"1737-44"},"PeriodicalIF":0.0,"publicationDate":"1991-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88229687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 22

Lateral root initiation in Marsilea quadrifolia. I. Origin and histogensis of lateral roots. 四叶松的侧根形成。1 .侧根的起源和组织结构。

Canadian journal of botany. Journal canadien de botanique Pub Date : 1991-01-01 DOI: 10.1139/B91-018

B. L. Lin, V. Raghavan

{"title":"Lateral root initiation in Marsilea quadrifolia. I. Origin and histogensis of lateral roots.","authors":"B. L. Lin, V. Raghavan","doi":"10.1139/B91-018","DOIUrl":"https://doi.org/10.1139/B91-018","url":null,"abstract":"In Marsilea quadrifolia, lateral roots arise from modified single cells of the endodermis located opposite the protoxylem poles within the meristematic region of the parent root. The initial cell divides in four specific planes to establish a five-celled lateral root primordium, with a tetrahedral apical cell in the centre and the oldest merophytes and the root cap along the sides. The cells of the merophyte divide in a precise pattern to give rise to the cells of the cortex, endodermis, pericycle, and vascular tissues of the emerging lateral root. Although the construction of the parent root is more complicated than that of lateral roots, patterns of cell division and tissue formation are similar in both types of roots, with the various tissues being arranged in similar positions in relation to the central axis. Vascular connection between the lateral root primordium and the parent root is derived from the pericycle cells lying between the former and the protoxylem members of the latter. It is proposed that the central axis of the root is not only a geometric centre, but also a physiological centre which determines the fate of the different cell types.","PeriodicalId":80871,"journal":{"name":"Canadian journal of botany. Journal canadien de botanique","volume":"18 1","pages":"123-35"},"PeriodicalIF":0.0,"publicationDate":"1991-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76439839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 19