Regulation of the fusion of floral organs by temperature and gibberellic acid in the normal and solanifolia mutant of tomato (Lycopersicon esculentum)

1990 ◽  
Vol 68 (4) ◽  
pp. 713-718 ◽  
Author(s):  
K. N. Chandra Sekhar ◽  
V. K. Sawhney
Keyword(s):  
Lycopersicon Esculentum ◽  
Gibberellic Acid ◽  
Ammonium Chloride ◽  
Low Temperatures ◽  
Single Gene ◽  
Gibberellin Biosynthesis ◽  
Growth Substances ◽  
Apparent Effect ◽  
Floral Organs ◽  
Floral Apex

The flowers of a single gene homozygous recessive solanifolia (sf/sf) mutant of tomato (Lycopersicon esculentum) possess separate sepals, petals and stamens, and a gynoecium that consists of several carpels with separate styles. In contrast, in the normal tomato (cv. Pearson), floral organs of each whorl are either partially or completely fused. Different temperature conditions and gibberellic acid treatments had no effect on the ontogenetic fusion of sepals and petals of the mutant and normal flowers. However, low temperatures and gibberellic acid induced the separation of stamens and pistil in many of the normal flowers, and they enhanced the separation of carpels in mutant flowers. In contrast, high temperatures and 2-chlo-roethyltrimethyl ammonium chloride, an inhibitor of gibberellin biosynthesis, promoted the fusion of stamens and gynoecia of mutant flowers, but had no apparent effect on the normal flowers. The nonfusion of stamens and carpels, in both genotypes, was associated with an increase in the number of these organs, whereas their fusion was accompanied with a reduction in their number. It is proposed that the nonfusion of floral organs in the sf/sf mutant is partly related to changes in endogenous growth substances which, through an effect on the size of the floral apex, affect the number and fusion of stamens and carpels.

Ontogenetic study of the fusion of floral organs in the normal and "solanifolia" mutant of tomato (Lycopersicon esculentum)

1987 ◽  
Vol 65 (2) ◽  
pp. 215-221 ◽  
Author(s):  
K. N. Chandra Sekhar ◽  
V. K. Sawhney
Keyword(s):  
Lycopersicon Esculentum ◽  
Single Gene ◽  
Corolla Tube ◽  
Lateral Growth ◽  
Floral Organs ◽  
Lack Of Fusion ◽  
Organ Type ◽  
Gene Mutant ◽  
Ontogenetic Study ◽  
Single Ovary

A comparative study on the ontogeny of the fusion of floral organs of the normal (cv. Pearson) and a single-gene mutant, "solanifolia" (sf/sf), of tomato (Lycopersicon esculentum Mill.) was conducted. In the normal, floral organs were laterally fused, although the degree and the region of fusion varied in each organ type. In the mutant, the various organs either did not fuse or, if they did, were individually recognizable. The sepals and petals of mutant flowers, unlike those of the normal, did not form a calyx cup and a corolla tube, respectively, and this was related to the limited lateral growth of mutant primordia and the absence of growth in the interprimordial region. Also, petal primordia of the mutant were narrower in width at inception. The stamens of normal flowers were fused by interweaving rows of lateral and adaxial hairs on the anthers. The mutant stamens produced lateral and adaxial hairs, yet they were free. The nonfusion of mutant stamens was related to the smaller primordium widths, greater distance between the primordia, and the larger apex diameter at the time of stamen initiation. The gynoecium of normal flowers consisted of a single ovary, style, and stigma formed by the fusion of carpel primordia. In the mutant, the gynoecium consisted of several carpels, laterally adhered to each other, and each had a recognizable style and stigma. The lack of fusion of mutant carpels was attributed to the larger apex diameter of the mutant during carpel initiation.

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.

The role of temperature and its relationship with gibberellic acid in the development of floral organs of tomato (Lycopersicon esculentum)

1983 ◽  
Vol 61 (4) ◽  
pp. 1258-1265 ◽  
Author(s):  
V. K. Sawhney
Keyword(s):  
Lycopersicon Esculentum ◽  
Gibberellic Acid ◽  
Floral Organs ◽  
Lycopersicon Esculentum Mill ◽  
Temperature Regimes ◽  
Intensity Of Response

The role of different temperature regimes (low, 18 °C day: 15 °C night (LTR); intermediate, 23 °C day: 18 °C night (ITR); and high, 28 °C day: 23 °C night (HTR)) in the development of tomato (Lycopersicon esculentum Mill.) flowers was studied. In general, flowers produced in LTR contained significantly greater numbers of petals, stamens, carpels, and locules than did plants grown in HTR. In ITR, the number of these organs was intermediate to plants grown in LTR and HTR, but was not significantly different from them in all cases. Gibberellic acid (GA3) also induced an increase in the number of petals, stamens, carpels, and locules; however, its effect was much greater on plants grown in ITR and HTR than on LTR, implying that LTR may produce at least part of its effect through increased levels of endogenous gibberellins. The intensity of response to different temperature regimes was variable for each of the three cultivars studied.

A scanning electron microscope study of the development and surface features of floral organs of tomato (Lycopersicon esculentum)

1984 ◽  
Vol 62 (11) ◽  
pp. 2403-2413 ◽  
Author(s):  
K. N. Chandra Sekhar ◽  
V. K. Sawhney
Keyword(s):  
Lycopersicon Esculentum ◽  
Progressive Increase ◽  
Basal Region ◽  
Scanning Electron Microscope Study ◽  
Floral Organs ◽  
Surface Features ◽  
Staminal Tube ◽  
Floral Apex ◽  
Different Types ◽  
Scanning Electron

The initiation and development and the surface features of floral organs of tomato (Lycopersicon esculentum Mill.) were examined using scanning electron microscopy. After the transformation of the vegetative apex into the floral apex, the floral organs appeared in the following sequence: sepals, petals, stamens, and carpels. The pattern of initiation was helical for the sepals and simultaneous for petals, stamens, and carpels. There was a progressive increase in the diameter of the apex associated with the initiation of each whorl of organs. Following initiation, the sepal and petal primordia fused at the basal region by "zonal growth," but the cohesion of anthers to form a staminal tube occurred later in development and was achieved by the interlocking of epidermal hairs produced on the lateral and adaxial surfaces of anthers. Carpel primordia were produced at the circumference of the remaining meristem and were fused laterally early in development. Epidermal hairs of different types and frequencies were observed on the adaxial and abaxial surfaces of sepals and petals and on the adaxial and lateral surfaces of the anthers. In the gynoecium, hairs were present only on the lower half of the style and were absent on the ovary. Stomata were observed on the sepals, petals, and style, but not on the anthers or ovary. Raised stomata were present only on young developing sepals and the style and were absent on mature organs. Cuticular thickenings were also observed on the abaxial surfaces of sepals, petals, and stamens, but not on the gynoecium.

Ontogenetical and experimental studies of the floral apex of Portulaca grandiflora. 1. Histology of transformation of the shoot apex into the floral apex

1969 ◽  
Vol 47 (1) ◽  
pp. 133-140 ◽  
Author(s):  
Siti Raswati Soetiarto ◽  
Ernest Ball
Keyword(s):  
Shoot Apex ◽  
Experimental Studies ◽  
Floral Meristem ◽  
Vegetative Shoot ◽  
Floral Organs ◽  
Mature Flower ◽  
Floral Apex ◽  
Portulaca Grandiflora ◽  
Floral Primordia ◽  
Vegetative Shoot Apex

The vegetative apex was a low dome consisting of two layers of tunica surmounting a very small corpus. Foliar primordia originated as periclines in the flanks of T2. The transition apex became first a steep cone and then a hemisphere. All floral primordia—the two bracts, the two sepals, the several whorls of petals, the several whorls of stamens, and the carpels—originated in the manner of leaves, as periclines in T2 on the flanks of the apex. All appendages, including carpels, were therefore lateral. In the early transition, the apex had a brief stage in which there were three tunica layers, but the inner one was lost with the onset of the sepals. The bracts and the first sepal continued the normal positions of primordia for the vegetative phyllotaxy of 3/8, but with the second sepal, this phyllotaxy was lost, and petals, stamens, and carpels were produced in whorls. While leaves, bracts, sepals, and petals were produced in acropetal sequence, stamens were produced in basipetal sequence, and carpels appeared simultaneously. After carpels were formed, the rest of the floral apex underwent a brief period of expansion growth, achieving a diameter comparable to that of a shoot apex, but its substance was eventually incorporated into the carpel margins, which later produced the ovules. This agrees with the determinate nature of the floral apex. During the development of the first series of floral organs, the floral apex underwent continued increase in area, finally achieving a diameter several times that of the vegetative shoot apex. Its size and form were such that they were compared to those of some inflorescence apices. After development of the first series of floral organs, the subjacent tissues to the floral meristem underwent divisions and elongation at right angles to the axis, causing at first a flattening of the meristem, and eventually a cup-shaped form, with the carpels attached in the bottom of a bowl. The mature flower was thus perigynous, but this development arose quite differently from the perigyny as it is known from ontogenetic studies in the Rosaceae.

Effects of gibberellic acid on DNA synthesis and histology in the shoot apex of Helianthus annum during the transition to flowering

1975 ◽  
Vol 53 (22) ◽  
pp. 2650-2659 ◽  
Author(s):  
Haviva D. Langenauer ◽  
Dan Atsmon ◽  
Tova Arzee
Keyword(s):  
Gibberellic Acid ◽  
Central Zone ◽  
Hormonal Treatment ◽  
Synthetic Activity ◽  
Basal Cells ◽  
Tunica Layer ◽  
Floral Apex ◽  
Number Of Leaves ◽  
And Control ◽  
Transition To Flowering

Transition to flowering is described in gibberellic acid (GA) - treated and control plants of Helianthus annuus. Hormonal treatment accelerates reproductive development without reducing the number of leaves developed before flowering. Studies of [3H]thymidine incorporation in the apex show that a non-synthesizing summital group of cells, the central zone, is present in the vegetative as well as the transitional apex. During transition to the floral apex the size of the central zone is gradually diminished, as its peripheral and basal cells undergo synthetic activity and the apex develops a domed shape. In GA-treated shoots the order is changed so that development of a dome precedes activity in the central zone. Cells of the second tunica layer of the central zone are the last to incorporate thymidine. They are conspicuously enlarged and distinct before development of the inflorescence. It is suggested that this layer has a specialized role in flowering.

Effect of growth substances on the expression of flowering and study on pollen viability of hermaphrodite & male ower in the female clone “Mondouri local” of Teasle gourd (Momordica subangulata Blume. subsp. renigera)

2019 ◽  
Vol 8 (2) ◽  
pp. 63-66
Author(s):  
Abhishek Naik ◽  
Shirin Akhtar ◽  
Arup Chattopadhyay ◽  
Umesh Thapa ◽  
Pranab Hazra
Keyword(s):  
Gibberellic Acid ◽  
Pollen Tube ◽  
Silver Nitrate ◽  
Pollen Viability ◽  
Pollen Size ◽  
Normal Male ◽  
Growth Substances ◽  
Flowering Stage ◽  
Foliar Sprays ◽  
Small Pollen

Foliar sprays with gibberellic acid (GA) and silver nitrate (AgNO3) of di erent concentra ons at pre-flowering stage induced hermaphrodite and male owers on strictly gynoecious vines of teasle gourd (Momordica subangulata Blume. subsp. renigera). GA at 1500 ppm and AgNO3at 500 ppm were effective inducing more than 50% male owers in the female clone “Mondouri local”. AgNO3 at 750 ppm was effective in inducing 36.6% male and 33.9% hermaphrodite owers on same plant. The hermaphrodite ower had higher pollen size (103.57 μm) compared to that of natural male ower (94.94 μm). However, there existed no variation between pollen viability of bisexual ower (81.6%) and normal male ower (89.1%). However, germinability of the pollen of hermaphrodite ower was very low (14.16%) producing very small pollen tube (9 μm), though the bisexual ower did not produce any fruit on self-pollination.

Sign in / Sign up

Export Citation Format

Share Document