Floral development of Potamogeton densus

1973 ◽  
Vol 51 (3) ◽  
pp. 647-656 ◽  
Author(s):  
U. Posluszny ◽  
R. Sattler
Keyword(s):  
Floral Development ◽  
The Other ◽  
Floral Meristem ◽  
Developmental Sequence ◽  
Initial Activity ◽  
The Third ◽  
Stamen Primordia ◽  
Procambial Strand ◽  
Inflorescence Axis ◽  
Rates Of Growth

The floral appendages of Potamogeton densus are initiated in an acropetal sequence. The first primordia to be seen externally are those of the lateral tepals, though sectioning young floral buds (longitudinally, parallel to the inflorescence axis) reveals initial activity in the region of the lower median (abaxial) tepal and stamen at a time when the floral meristem is not yet clearly demarcated. The lateral (transversal) stamens are initiated simultaneously and unlike the median stamens each arises as two separate primordia. The upper median (adaxial) tepal and stamen develop late in relation to the other floral appendages, and in some specimens are completely absent. Rates of growth of the primordia vary greatly. Though the lower median tepal and stamen are initiated first, they grow slowly up to gynoecial inception, while the upper median tepal appears late in the developmental sequence but grows rapidly, soon overtaking the other tepal primordia. The four gynoecial primordia arise almost simultaneously, although variation in their sequence of inception occurs. The two-layered tunica of the floral apices gives rise to all floral appendages through periclinal divisions in the second layer. The third layer (corpus) is involved as well in the initiation of the stamen primordia. Procambial strands develop acropetally, lagging behind primordial initiation. The lateral stamens though initiating as two primordia each form a single, central procambial strand, which differentiates after growth between the two primordia of the thecae has occurred. A great amount of deviation from the normal tetramerous flower is found, including completely trimerous flowers, trimerous gynoecia with tetramerous perianth and androecium, and organs differentiating partially as tepals and partially as stamens.

Floral development of Alisma triviale

1972 ◽  
Vol 50 (3) ◽  
pp. 619-627 ◽  
Author(s):  
V. Singh ◽  
R. Sattler
Keyword(s):  
Floral Development ◽  
Vascular Tissue ◽  
Radial Symmetry ◽  
Early Growth ◽  
Stages Of Development ◽  
The Third ◽  
Lack Of Fusion ◽  
Stamen Primordia ◽  
Procambial Strand ◽  
The Many

The primordia of the floral appendages are initiated in acropetal order. They develop in the same order in which they appear but for the petals, which are retarded in their early growth and mature rapidly shortly before anthesis. While the sepal primordia are dorsiventral from their inception, the primordia of other appendages are of nearly radial symmetry and become more or less dorsiventral in their later stages of development. Each petal primordium together with the primordia of a stamen pair arise on one common petal–stamen (CA) primordium. The many pistil primordia arise on three antesepalous gynoecial bulges and the area between them. Thus, in its development the flower exhibits primarily a tricyclic trimerous plan. The floral apices have a two-layered tunica up to the stage of pistil inception. The initiation of all floral appendages occurs by periclinal divisions in the second layer. The third layer (corpus) may contribute, especially in the case of the petal–stamen primordia and the gynoecial bulges. The development of procambium is acropetal. Each primordium receives a single procambial strand shortly after its initiation. Thus, procambial differentiation occurs as a response to primordial inception and not according to the principle of the conservatism of vascular tissue. Additional procambial strands may differentiate as a response to increase in size. The relationships of Alisma to some ranalian families are discussed. Since the floral pattern of Alisma may be considered as a secondary derivation from a trimerous pattern, it does not appear primitive at all. Other primitive features such as apocarpy and lack of fusion of pistil margins are however retained. Thus, Alisma is a good example for heterobathmy.

scholarly journals SlGT11 Controls Floral Organ Patterning and Floral Determinacy in Tomato

2020 ◽  
Author(s):  
Liling Yang ◽  
Shilian Qi ◽  
Arfa touqeer ◽  
Haiyang Li ◽  
Xiaolan Zhang ◽  
...  
Keyword(s):  
Floral Development ◽  
Bulked Segregant Analysis ◽  
Floral Organ ◽  
Fruit Production ◽  
Floral Meristem ◽  
Rnai Silencing ◽  
The Third ◽  
Spatiotemporal Expression ◽  
Higher Temperature ◽  
Floral Determinacy

Abstract Background: Flower development directly affects fruit production in tomato. Despite the framework mediated by ABC genes have been established in Arabidopsis, the spatiotemporal precision of floral development in tomato has not been well examined.Results: Here, we analyzed a novel tomato stamenless like flower (slf) mutant in which the development of stamens and carpels is disturbed, with carpelloid structure formed in the third whorl and ectopic formation of floral and shoot apical meristem in the fourth whorl. Using bulked segregant analysis (BSA), we assigned the causal mutation to the gene Solanum lycopersicum GT11 (SlGT11) that encodes a transcription factor belonging to Trihelix gene family. SlGT11 is expressed in the early stages of the flower and the expression becomes more specific to the primordium position corresponding to stamens and carpels in later stages of the floral development. Further RNAi silencing of SlGT11 verifies the defective phenotypes of the slf mutant. The carpelloid stamen in slf mutant indicates that SlGT11 is required for B-function activity in the third whorl. The failed termination of floral meristem and the occurrence of floral reversion in slf indicate that part of the C-function requires SlGT11 activity in the fourth whorl. Furthermore, we find that at higher temperature, the defects of slf mutant are substantially enhanced, with petals transformed into sepals, all stamens disappeared, and the frequency of ectopic shoot/floral meristem in fourth whorl increased, indicating that SlGT11 functions in the development of the three inner floral whorls. Consistent with the observed phenotypes, it was found that B, C and an E-type MADS-box genes were in part down regulated in slf mutants.Conclusions: Together with the spatiotemporal expression pattern, we suggest that SlGT11 functions in floral organ patterning and maintenance of floral determinacy in tomato.

Problems of Growth of the African Migratory Locust

1938 ◽  
Vol 29 (4) ◽  
pp. 425-456 ◽  
Author(s):  
A. J. Duarte
Keyword(s):  
Dry Weight ◽  
Hind Femur ◽  
The Other ◽  
The Third ◽  
Cell Divisions ◽  
First Instar ◽  
Wet Weight ◽  
Solitary Males ◽  
Rates Of Growth ◽  
Control Batch

General Growth.Generally, females have higher rates of growth than males. The phases, however, do not show appreciable differences in the rate. The pronotum has for increase in length the highest values which decrease throughout the instars (whereas the constants for the other parts remain fairly stable up to the fifth instar).Dyar's rule was applied for the growth in length of the middle femur and the width of the head, and it was found that the rule holds good for these parts.Przibram's rule, as modified by Bodenheimer, holds true for the growth in length of the different parts and shows the occurrence of latent cell-divisions varying from one (width of head and of pronotum) to four (length of pronotum). The number of latent cell-divisions keeps fairly constant in both phases.For wet weight Przibram's principle is inapplicable, owing to the large percentage of differences between the actual and calculated values.Gregarious males are heavier than solitary males up to the third stadium ; gregarious females are heavier than solitary females up to the third stadium ; fourth, fifth and adult stadia being characterized by higher values in wet weight for solitary females than for gregarious females. Females have higher rates of increase in wet weight than males. No significant differences exist in the rates of increase between gregarious and solitary individuals. In the fifth-adult stadium all the rates decrease except in gregarious females, which show a rise.Gregarious insects have higher values in dry weight than solitary insects, except solitary females in the adult stadium. The coefficients are higher for females than for males.The rates of increase reach the highest values in the second-third stadium of gregarious insects and solitary females, whereas solitary males have their highest value in the fourth-fifth stadium.With the exception of solitary females, all the rates of growth in dry weight decline in the fifth-adult stadium.The rates of growth of the hind legs obtained from the cube-roots of their wet weights are compared with the rates of linear growth of the hind femora. Their variation throughout the instars seems to be in opposite directions. Therefore it is suggested that the rates of growth in wet weight of the hind legs and the rates of growth in length of the respective hind femora are independent of each other.Growth of the parts.The application of the exponential allometry formula y=bxα to the data on dimensions of the parts of Locusta shows the existence of negative, positive and almost isometric growth.The pronotum has the highest value for the growth in length relatively to the growth in length of the middle femur ; the lowest value pertains to the growth in width of the head.Males have higher values than females ; phase gregaria exhibits higher growth-ratios than phase solitaria.With the exception of the hind femur the growth-ratios decline throughout the instars. The greatest decline pertains to the growth in length of the pronotum.A growth-gradient exists in Locusta with the highest value in the pronotum. The middle femur divides the growth-gradient into two parts : an anterior part with values decreasing with the growth of the insect, and a posterior part whose values increase with its growth.Effects of the amputation of the hind tibiae on crowded locusts.The effects obtained by mutilating both hind tibiae of three hundred first instar hoppers of Locusta migratoria migratorioides and placing them in a crowded condition are compared with the effects obtained by crowding a batch of the same number of first instar unoperated insects.The insects with their hind tibiae cut off did not develop as far as those of the control batch ; the differences in dimensions are greater for the hind femur than for the other parts of the body.In the experimental batch the hind femur, as a consequence of its useless condition, became extremely short as compared with the elytra, bringing the ratio E/F to a high value (over 1·950), thus leading to a false interpretation.The occurrence of the black-orange coloration in both batches suggested that both developed towards phase gregaria. This coloration was stronger and more uniform in the control batch than it was in the experimental batch. Thus the control animals developed into a better gregarious type.

Floral development of Aponogeton natans and A. undulatus

1977 ◽  
Vol 55 (9) ◽  
pp. 1106-1120 ◽  
Author(s):  
V. Singh ◽  
R. Sattler
Keyword(s):  
Cell Division ◽  
Developmental Stage ◽  
Floral Development ◽  
Developmental Stages ◽  
Point Of View ◽  
Stages Of Development ◽  
The Third ◽  
Procambial Strand ◽  
Tunica Layer

The primordia of the floral appendages are initiated in an acropetal succession. Members of the same whorl appear nearly simultaneously. The gynoecial whorl and the two staminal whorls are trimerous, whereas the perianth consists only of two anteriolateral tepals. However, the posterior (adaxial) tepal may be present as an extremely reduced buttress whose growth becomes arrested immediately after its inception. If this somewhat questionable tepal rudiment is included we have a perfectly trimerous and tetracyclic flower with alternation of successive whorls. Subtending bracts of the flowers are completely missing in all developmental stages. While the tepal primordia are dorsiventral from their inception, the stamen and pistil (carpel) primordia originate as hemispherical mounds which become dorsiventral in subsequent stages of development. Each pistil (carpel) primordium becomes horseshoe shaped. As the margins grow up and contact they fuse postgenitally. No cross zone is formed. Placentation is submarginal. In A. natans eight ovules are formed and in A. undulatus only two arise; all ovules are bitegmic. The floral apices have a two-layered tunica up to the stage of pistil formation. The inception of all floral appendages (including the ovules) occurs by periclinal cell division in the second tunica layer. The third layer (corpus) may contribute to the formation of the stamens and pistils. Each appendage primordium receives only one procambial strand which begins to differentiate after the inception of the primordium. The questionable rudimentary tepal buttress lacks a procambial strand. Apparently it does not reach the developmental stage at which procambial induction occurs. From the point of view of floral development, the two species of Aponogeton differ drastically from members of the Alismatales studied so far. Among the Helobiae, the Aponogetonaceae appear to be most closely related to the Scheuchzeriaceae and the Juncaginaceae (Triglochinaceae).

scholarly journals SlGT11 controls floral organ patterning and floral determinacy in tomato

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Liling Yang ◽  
Shilian Qi ◽  
Arfa Touqeer ◽  
Haiyang Li ◽  
Xiaolan Zhang ◽  
...  
Keyword(s):  
Floral Development ◽  
Bulked Segregant Analysis ◽  
Floral Organ ◽  
Fruit Production ◽  
Floral Meristem ◽  
Rnai Silencing ◽  
The Third ◽  
Spatiotemporal Expression ◽  
Higher Temperature ◽  
Floral Determinacy

Abstract Background Flower development directly affects fruit production in tomato. Despite the framework mediated by ABC genes have been established in Arabidopsis, the spatiotemporal precision of floral development in tomato has not been well examined. Results Here, we analyzed a novel tomato stamenless like flower (slf) mutant in which the development of stamens and carpels is disturbed, with carpelloid structure formed in the third whorl and ectopic formation of floral and shoot apical meristem in the fourth whorl. Using bulked segregant analysis (BSA), we assigned the causal mutation to the gene Solanum lycopersicum GT11 (SlGT11) that encodes a transcription factor belonging to Trihelix gene family. SlGT11 is expressed in the early stages of the flower and the expression becomes more specific to the primordium position corresponding to stamens and carpels in later stages of the floral development. Further RNAi silencing of SlGT11 verifies the defective phenotypes of the slf mutant. The carpelloid stamen in slf mutant indicates that SlGT11 is required for B-function activity in the third whorl. The failed termination of floral meristem and the occurrence of floral reversion in slf indicate that part of the C-function requires SlGT11 activity in the fourth whorl. Furthermore, we find that at higher temperature, the defects of slf mutant are substantially enhanced, with petals transformed into sepals, all stamens disappeared, and the frequency of ectopic shoot/floral meristem in fourth whorl increased, indicating that SlGT11 functions in the development of the three inner floral whorls. Consistent with the observed phenotypes, it was found that B, C and an E-type MADS-box genes were in part down regulated in slf mutants. Conclusions Together with the spatiotemporal expression pattern, we suggest that SlGT11 functions in floral organ patterning and maintenance of floral determinacy in tomato.

Floral development of Ruppia maritima var. maritima

1974 ◽  
Vol 52 (7) ◽  
pp. 1607-1612 ◽  
Author(s):  
U. Posluszny ◽  
R. Sattler
Keyword(s):  
Floral Development ◽  
Early Ontogeny ◽  
Main Axis ◽  
Ruppia Maritima ◽  
Procambial Strand ◽  
Inflorescence Axis ◽  
Floral Apex ◽  
Median Position ◽  
Floral Bud

A hyaline, unvascularized sheath envelops a portion of the inflorescence near maturity. Though resembling an appendage of the main axis, in early ontogeny it develops as a prophyll of the renewal growth apex below the inflorescence. Two flowers develop on the inflorescence axis, subopposite each other. Fertile appendages are initiated in an acropetal sequence on each floral bud. The first to form, in the median position, are the two stamens, the lower preceding the upper. Each stamen develops two bisporangiate thecae separated by a broad connective. A dorsiventral outgrowth is initiated slightly abaxially near the tip of the connective at the stage of theca differentiation. This outgrowth appears to be homologous with a similar outgrowth in Potamogeton densus, but not with the sterile appendages of the Potamogeton flower which, by some authors, have incorrectly been interpreted as connective outgrowths. Each carpel arises as a radial primordium which becomes peltate after its inception. One ovule is initiated at the adaxial portion (Querzone). The stigma becomes broad and flat, lobing at its margins. A slight outgrowth develops at the abaxial wall of the carpel. The floral apex has a two-layered tunica. The primordia of the stamens, carpels, and ovules arise by periclinal divisions in the second layer. Procambial development is acropetal following closely primordial inception. Each appendage, including the ovule, receives one procambial strand. The outgrowths of the connective and the carpel lack procambium.

scholarly journals SlGT11 Controls Floral Organ P atterning and F loral Determinacy in Tomato

2020 ◽  
Author(s):  
Liling Yang ◽  
Shilian Qi ◽  
Arfa touqeer ◽  
Haiyang Li ◽  
Xiaolan Zhang ◽  
...  
Keyword(s):  
Floral Development ◽  
Bulked Segregant Analysis ◽  
Floral Organ ◽  
Fruit Production ◽  
Floral Meristem ◽  
Rnai Silencing ◽  
The Third ◽  
Spatiotemporal Expression ◽  
Higher Temperature ◽  
Type Gene

Abstract Background: Flower development directly affects fruit production in tomato. Despite the framework mediated by ABC genes have been established in Arabidopsis, the spatiotemporal precision of floral development in tomato has not been well examined.Results: Here, we analyzed a novel tomato stamenless like flower (slf) mutant in which the development of stamens and carpels is disturbed, with carpelloid structure formed in the third whorl and ectopic formation of floral and shoot apical meristem in the fourth whorl. Using bulked segregant analysis (BSA), we assigned the causal mutation to the gene Solanum lycopersicum GT11 (SlGT11) that encodes a transcription factor belonging to Trihelix gene family. SlGT11 is expressed in the early stages of the flower and the expression becomes more specific to the primordium position corresponding to stamens and carpels in later stages of the floral development. Further RNAi silencing of SlGT11 verifies the defective phenotypes of the slf mutant. The carpelloid stamen in slf mutant indicates that SlGT11 functions like as a B-type gene in the third whorl. The failed termination of floral meristem and the occurrence of floral reversion in slf indicate that SlGT11 also functions as a C-type gene in the fourth whorl. Furthermore, we find that at higher temperature, the defects of slf mutant are substantially enhanced, with petals transformed into sepals, all stamens disappeared, and the frequency of ectopic shoot/floral meristem in fourth whorl increased, indicating that SlGT11 may have the function of tomato B and E class gene in the development of second and fourth whorls.Conclusions: Together with the spatiotemporal expression pattern, we suggest that SlGT11 functions in floral organ patterning and maintenance of floral determinacy in tomato.

scholarly journals SlGT11 Controls Floral Organ Patterning and Floral Determinacy in Tomato

2020 ◽  
Author(s):  
Liling Yang ◽  
Shilian Qi ◽  
Arfa touqeer ◽  
Haiyang Li ◽  
Xiaolan Zhang ◽  
...  
Keyword(s):  
Floral Development ◽  
Bulked Segregant Analysis ◽  
Floral Organ ◽  
Fruit Production ◽  
Floral Meristem ◽  
Rnai Silencing ◽  
The Third ◽  
Spatiotemporal Expression ◽  
Higher Temperature ◽  
Floral Determinacy

Abstract Background: Flower development directly affects fruit production in tomato. Despite the framework mediated by ABC genes have been established in Arabidopsis, the spatiotemporal precision of floral development in tomato has not been well examined.Results: Here, we analyzed a novel tomato stamenless like flower (slf) mutant in which the development of stamens and carpels is disturbed, with carpelloid structure formed in the third whorl and ectopic formation of floral and shoot apical meristem in the fourth whorl. Using bulked segregant analysis (BSA), we assigned the causal mutation to the gene Solanum lycopersicum GT11 (SlGT11) that encodes a transcription factor belonging to Trihelix gene family. SlGT11 is expressed in the early stages of the flower and the expression becomes more specific to the primordium position corresponding to stamens and carpels in later stages of the floral development. Further RNAi silencing of SlGT11 verifies the defective phenotypes of the slf mutant. The carpelloid stamen in slf mutant indicates that SlGT11 is required for B-function activity in the third whorl. The failed termination of floral meristem and the occurrence of floral reversion in slf indicate that part of the C-function requires SlGT11 activity in the fourth whorl. Furthermore, we find that at higher temperature, the defects of slf mutant are substantially enhanced, with petals transformed into sepals, all stamens disappeared, and the frequency of ectopic shoot/floral meristem in fourth whorl increased, indicating that SlGT11 functions in the development of the three inner floral whorls. Consistent with the observed phenotypes, it was found that B, C and an E-type MADS-box genes were in part down regulated in slf mutants.Conclusions: Together with the spatiotemporal expression pattern, we suggest that SlGT11 functions in floral organ patterning and maintenance of floral determinacy in tomato.

Floral development of Butomus umbellatus

1974 ◽  
Vol 52 (1) ◽  
pp. 223-230 ◽  
Author(s):  
V. Singh ◽  
R. Sattler
Keyword(s):  
Floral Development ◽  
Stamen Primordia ◽  
Procambial Strand ◽  
Tunica Layer ◽  
Rapid Sequence ◽  
Floral Apex ◽  
Outer Tepal ◽  
Primary Pattern

The primordia of the floral appendages appear in acropetal succession and develop in the order in which they appear. The primordia of each whorl of appendages are formed in a rapid sequence. After the inception of outer tepal primordia, the floral apex becomes triangular. On each angle, one inner tepal primordium together with the primordia of a pair of outer stamens and an inner stamen is formed. The triangularity of the floral apex might be interpreted as an indication of the formation of petal–stamen (CA) primordia as reported for Alisma and Hydrocleis. If this is the case, the primary pattern of organogenesis of the Butomus flower is trimerous and tetracyclic, i.e. one whorl of outer tepals, one complex of inner tepals and stamens, and two whorls of pistils. The floral apices have a two-layered tunica surrounding a central corpus. The initiating divisions in the formation of all floral appendages occur in the second tunica layer. In the case of stamen primordia, the outer corpus is also involved. Procambial development is acropetal. One procambial strand differentiates into each floral appendage shortly after its inception. Additional procambial strands are formed in the pedicel and the perianth and gynoecium. The relationships of Butomus to the Magnoliidae are discussed.

scholarly journals Spatial orientation of gynoecium in legumes and beyond: Commentary to the paper of Wang et al. (2021)

2021 ◽  
Author(s):  
Andrey A. Sinjushin ◽  
Keyword(s):  
Spatial Orientation ◽  
Special Interest ◽  
Floral Meristem ◽  
The Third ◽  
Flower Symmetry ◽  
Inflorescence Axis ◽  
Wide Range ◽  
Range Of Variation

The third largest angiosperm family, Leguminosae, exhibits a relatively wide range of variation in morphology of gynoecium. Some of gynoecial patterns found in this taxon are of special interest, as they resemble ones previously described in the earliest angiosperms. The different orientations of carpels in legumes appear easily switchable through changes in flower symmetry and floral meristem sizes. Regardless of orientation of a single carpel with respect to the inflorescence axis, the placenta-bearing suture invariably remains adaxial as related to the floral axis. This conclusion relaxes the existing controversies between the supposed megasporophyll- derived nature of the carpel and observed diversity of placentation in known Mesozoic angiosperms.

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