Interpretations of determination and canalisation of stamen development in a tomato mutant

1979 ◽  
Vol 57 (22) ◽  
pp. 2471-2477 ◽  
Author(s):  
V. K. Sawhney ◽  
R. I. Greyson
Keyword(s):  
Gibberellic Acid ◽  
Single Gene ◽  
Progressive Increase ◽  
Stamen Development ◽  
Early Stages ◽  
Floral Buds ◽  
Stamen Primordia ◽  
Recessive Mutant ◽  
Tomato Mutant

Floral buds of different sizes of the single-gene recessive mutant stamenless-2 (sl2/sl2) of tomato were treated with gibberellic acid (GA3) and the development of staminal features in each bud was followed. The results show that the application of GA3 to buds with stamen primordia at the early stages of initiation (up to 0.1 mm in length) induced the formation of normal-looking stamens. However, with a progressive increase in stamen size, less and less of the normal stamen features were produced following the GA3 treatment. Ultimately, buds with stamen primordia 0.8 mm long or longer failed to respond to GA3 and produced all the mutant characteristics. These results are discussed in terms of Waddington's concept of “determination” and “canalisation” of development.

Morphogenesis of the stamenless-2 mutant in tomato. II. Modifications of sex organs in the mutant and normal flowers by plant hormones

1973 ◽  
Vol 51 (12) ◽  
pp. 2473-2479 ◽  
Author(s):  
Vipen K. Sawhney ◽  
Richard I. Greyson
Keyword(s):  
Gibberellic Acid ◽  
Plant Hormones ◽  
Indoleacetic Acid ◽  
Single Gene ◽  
Apparent Effect ◽  
Viable Pollen ◽  
Stamen Development ◽  
Auxin Content

Application of gibberellic acid (GA3) to young plants of a single gene recessive stamenless-2 (sl2/sl2) mutant of tomato produced 'phenocopies' of the normal plants. Unlike the untreated sl2/sl2 mutant, flowers of GA3-treated plants bore no external ovules, possessed more yellow-pubescent stamens and fewer carpelloid stamens per flower, and produced laterally fused stamens. Stamen length at maturity was similar to normal flowers. In addition, viable pollen resembling the normal was produced in GA3-treated sl2/sl2 flowers. It was also found that GA3 was more effective than GA4+7 in inducing stamen development. Normal plants treated with GA3 produced multicarpellary and multilocular ovaries. Indoleacetic acid (IAA) induced the carpellization of stamens in sl2/sl2 flowers but had no apparent effect on the flowers of normal plants. It is proposed that added gibberellins promote maleness in systems where there is an inhibition or abnormality of stamen development, whereas they stimulate femaleness (possibly through an increase in auxin content) in systems with normal stamen development.

scholarly journals Reproductive Meristem22 is a unique marker for the early stages of stamen development

2011 ◽  
Vol 55 (6) ◽  
pp. 657-664 ◽  
Author(s):  
Elisson Romanel ◽  
Pradeep Das ◽  
Richard M. Amasino ◽  
Jan Traas ◽  
Elliot Meyerowitz ◽  
...  
Keyword(s):  
Stamen Development ◽  
Early Stages

L'androcée centripète d’Ochna atropurpurea

1978 ◽  
Vol 56 (20) ◽  
pp. 2500-2511 ◽  
Author(s):  
Fernand Pauzé ◽  
Rolf Sattler
Keyword(s):  
Floral Development ◽  
Fundamental Importance ◽  
Reliable Criterion ◽  
Early Stages ◽  
Stamen Primordia ◽  
Family Level ◽  
Definite Pattern ◽  
Phylogenetic Lineages ◽  
Floral Bud

After the inception of usually five sepals and five petals, five primary androecial primordia are initiated as broad bulges in alternation with the narrow petal primordia. On each of these primary androecial primordia, usually seven stamen primordia (i.e., secondary androecial primordia) are formed centripetally in a definite pattern. The fasciculate pattern of the androecium is noticeable only in very early stages of floral development since the stamen primordia of adjacent primary androecial primordia approach each other as closely as the stamen primordia of the same primary androecial primordium. Furthermore, the number and arrangement of the stamen primordia on the primary androecial primordia may vary even within the same floral bud. The total number of stamens per floral bud varied from 26 to 43, while the number of petals varied from 4 to 6. Some of the stamen primordia, especially among the inner ones, sometimes develop into filament-like staminodia. The findings support the view that the Dilleniidae cannot be generally characterized by a centrifugal androecium. The sequence of stamen inception is not necessarily of such fundamental importance that it is a reliable criterion for the reconstitution of major phylogenetic lineages at or above the rank of families. Shifts from a centrifugal to a centripetal androecium or vice versa may have occurred during the evolution of taxa at the ordinal (or even family) level. [Translated by the journal]

Gibberellic acid induced multilocular fruits in tomato and the role of locule number and seed number in fruit size

1978 ◽  
Vol 56 (22) ◽  
pp. 2831-2835 ◽  
Author(s):  
V. K. Sawhney ◽  
D. H. Dabbs
Keyword(s):  
Gibberellic Acid ◽  
Fruit Size ◽  
Progressive Increase ◽  
Floral Initiation ◽  
Regression Analyses ◽  
Seed Number ◽  
Fresh Weight ◽  
Tomato Plants ◽  
Locule Number

Young tomato plants were treated with gibberellic acid (GA3) at a stage before floral initiation. In the first truss produced after the treatment, the fresh weight and size of the fruit was lower than the controls but was significantly higher in trusses 2 to 4. Also, whereas in controls the fresh weight and size of tomato fruits steadily declined from truss 1 to truss 4, in GA3-treated plants there was a progressive increase in the fresh weight and size of the fruit. The number of locules per fruit of GA3-treated plants was also greater than the controls but not the number of seeds per fruit. Regression analyses show that both the locule number and seed number have a significant correlation with the fresh weight of the fruit and that these relationships are independent of each other.

Methodology of gene transfer by homoeologous recombination into Triticum turgidum: transfer of K+/Na+ discrimination from Triticum aestivum

Genome ◽  
1992 ◽  
Vol 35 (4) ◽  
pp. 639-646 ◽  
Author(s):  
J. Dvořák ◽  
J. Gorham
Keyword(s):  
Triticum Aestivum ◽  
Salt Stress ◽  
Triticum Turgidum ◽  
Single Gene ◽  
Large Population ◽  
Wheat Chromosome ◽  
Homoeologous Recombination ◽  
Salt Stress Tolerance ◽  
Recessive Mutant ◽  
Or Genes

Triticum aestivum (2n = 6x = 42) differs from T. turgidum (2n = 4x = 28) by superior ability to exclude Na+ and accumulate K+ under salt stress. Chromosome 4D has a major affect on the enhancement of this trait in T. aestivum. To transfer this trait to T. turgidum, T. turgidum chromosome 4B was targeted for homoeologous recombination with chromosome 4D in the genetic background of T. turgidum, utilizing recessive mutant ph1c to enhance meiotic heterogenetic chromosome pairing. Since the basis of the genetic control of this trait by chromosome 4D was not known, a large population of random recombinant lines involving the alien chromosome and the wheat chromosome had to be produced. It was hypothesized that assaying lines in such a population for the trait would facilitate identification of those in which the gene or genes controlling the trait were incorporated into the T. turgidum chromosome. Forty lines with recombinant chromosomes were obtained. Thirty-nine recombination events involving chromosome 4D involved the targeted chromosome 4B. The ratio of K+/Na+ in leaves of plants grown under salt stress was determined for 27 lines. Nine lines showed enhanced K+/Na+ ratios. Evidence is presented that this trait is controlled by a single gene locus, designated here as Kna1. The locus is distal to the subterminal C-band in the long arm of chromosome 4D.Key words: wheat, linkage map distortion, salt stress tolerance.

scholarly journals A mutation in the age-1 gene in Caenorhabditis elegans lengthens life and reduces hermaphrodite fertility.

Genetics ◽  
1988 ◽  
Vol 118 (1) ◽  
pp. 75-86 ◽  
Author(s):  
D B Friedman ◽  
T E Johnson
Keyword(s):  
Caenorhabditis Elegans ◽  
Life Span ◽  
Genetic Locus ◽  
Single Gene ◽  
Reproductive Period ◽  
Mutant Form ◽  
Probability Of Survival ◽  
Maximal Life Span ◽  
Programmed Aging ◽  
Recessive Mutant

Abstract age-1(hx546) is a recessive mutant allele in Caenorhabditis elegans that results in an increase in mean life span averaging 40% and in maximal life span averaging 60% at 20 degrees; at 25 degrees age-1(hx546) averages a 65% increase in mean life span (25.3 days vs. 15.0 days) and a 110% increase in maximum life span (46.2 days vs. 22.0 days for wild-type hermaphrodites). Mutant males also show extended life spans. age-1(hx546) is associated with a 75% decrease in hermaphrodite self-fertility as compared to the age-1+ allele at 20 degrees. Using two novel strategies for following the segregation of age-1, we present evidence that longer life results from a mutation in a single gene that increases the probability of survival at all chronological ages. The long-life and reduced-fertility phenotypes cosegregate and are tightly linked to fer-15, a locus on linkage group II. age-1(hx546) does not affect the timing of larval molts, the length of embryogenesis, food uptake, movement, or behavior in any way tested. Although age-1(hx546) lowers hermaphrodite self-fertility, it does not markedly affect the length of the reproductive period with all the increase in life expectancy due to an increase in the length of postreproductive life. In so far as we are aware, this mutant in age-1 is the only instance of a well-characterized genetic locus in which the mutant form results in lengthened fife. It is likely that the action of age-1 in lengthening life results not from eliminating a programmed aging function but rather from reduced hermaphrodite self-fertility or from some other unknown metabolic or physiologic alteration.

scholarly journals Speciation of heavy metals during co-composting of livestock manure

2015 ◽  
Vol 17 (3) ◽  
pp. 19-23 ◽  
Author(s):  
Shazia Gul ◽  
Alia Naz ◽  
Iftikhar Fareed ◽  
Abdullah Khan ◽  
Muhammad Irshad
Keyword(s):  
Heavy Metals ◽  
Extraction Method ◽  
Extraction Process ◽  
Progressive Increase ◽  
Livestock Manure ◽  
Composting Process ◽  
Early Stages ◽  
Extracting Agents

Abstract Heavy metals determination in manures provides beneficial information to predict the availability and the potential contamination of environment. Therefore, a study was carried out to investigate heavy metals changes in livestock manure during a co-composting process. The metals were stepwise fractionated into exchangeable, adsorbed, organically bound, carbonate precipitated and residual forms by extracting with 0.5M KNO3, de-ionized water, 0.5M NaOH, 0.05M Na2EDTA and 4M HNO3, respectively. During the extraction process, the amount of metals remained highly dependent on an extraction method and stage of manure composting. Extractions released heavy metals contents in the final composted manure as Zn > Cu > Pb > Cr > Ni > Cd. Irrespective of the days of composting, extracting agents differed in the order HNO3 > Na2EDTA > NaOH > KNO3 > H2O for all heavy metals. Higher concentrations of heavy metals were observed during the early stages of composting. Conversely, there was a progressive increase in the concentrations of K, Ca and Mg during composting of manure. Total C in the manure reduced with composting days.

scholarly journals Gibberellic Acid Slows Postharvest Degreening of 'Oroblanco' Citrus Fruits

HortScience ◽  
2001 ◽  
Vol 36 (5) ◽  
pp. 937-940 ◽  
Author(s):  
Ron Porat ◽  
Xuqiao Feng ◽  
Moshe Huberman ◽  
David Galili ◽  
Raphael Goren ◽  
...  
Keyword(s):  
Gibberellic Acid ◽  
Storage Temperature ◽  
Color Change ◽  
Progressive Increase ◽  
Fruit Color ◽  
Slight Effect ◽  
Peel Color ◽  
Early Maturing ◽  
And Storage ◽  
Storage Temperatures

'Oroblanco' is an early-maturing pummelo-grapefruit hybrid (Citrus grandis Osbeck × C. paradisi Macf.). The fruit are usually picked and marketed while the peel color is still green; however, in some cases they can lose this green color during postharvest shipping and storage, which diminishes their commercial value. The effects of storage temperatures, gibberellic acid (GA), ethylene, and 1-methylcyclopropene (1-MCP) on the degreening of 'Oroblanco' fruit were examined. Storage temperature was critical for retaining fruit color: at 2 °C the fruit remained green for a period up to 5 weeks, whereas at storage temperatures of 6, 12, and 20 °C there was a progressive increase in the rate of degreening. Applications of GA, either as preharvest sprays or as postharvest dip treatments, effectively retained the green fruit color. Ethylene exposures up to 100 μL·L-1 for 3 days had only a slight effect on fruit degreening, and 1-MCP treatments up to 200 nL·L-1 for 16 hours had no effect at all. The slight influence of ethylene and the ineffectiveness of 1-MCP on fruit color change can not be attributed to difficulties in their application, since in the same experiments ethylene markedly induced peduncle abscission, and 1-MCP effectively inhibited this ethylene effect. Accordingly, ethylene had only a relatively small effect on the induction of chlorophyllase enzyme activity in green 'Oroblanco' peel tissue.

Immunofluorescence studies for myosin, α-actinin and tropomyosin in developing hearts of normal and cardiac lethal mutant Mexican axolotls, Ambystoma mexicanum

Development ◽  
1980 ◽  
Vol 55 (1) ◽  
pp. 1-15
Author(s):  
Larry F. Lemanski ◽  
Rebecca A. Fuldner ◽  
Daniel J. Paulson
Keyword(s):  
Heart Function ◽  
Mutant Gene ◽  
Progressive Increase ◽  
Ambystoma Mexicanum ◽  
Myocardial Cells ◽  
Lethal Mutant ◽  
Normal Cells ◽  
Immunofluorescence Studies ◽  
Recessive Mutant ◽  
Mutant Cells

Recessive mutant gene c in axolotl embryos results in an absence of normal heart function. Immunofluorescence studies were done to determine the distributions of myosin, tropomyosin and α-actinin in the hearts of normal and mutant siblings. Anti-myosin specifically stains the A bands of myofibrils in normal hearts and reveals a progressive increase in myofibril organization with development. Mutant hearts display less staining for myosin than normal and localization is mainly in amorphous collections. Anti-α-actinin stains the Z lines of myofibrils in normal myocytes. Mutant cells also have significant staining for α-actinin but show no striations. Antitropomyosin intensely stains the I bands of myofibrils in normal cells; however, there is very little staining for tropomyosin in mutant hearts. Thus, mutant myocardial cells have reduced but significant amounts of actin (Lemanski, Mooseker, Peachey & lyengar, 1976) and myosin, even though non-filamentous, and substantial amounts of α-actinin. The cells appear to contain little tropomyosin.

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