scholarly journals Monoicy in A. angustifolia (Bert.) O. Kuntze (Araucariaceae): I. Morphological aspects of the reproductive structures

2009 ◽  
Vol 81 (4) ◽  
pp. 701-705 ◽  
Author(s):  
Valdir M. Stefenon ◽  
Clarissa A. Caprestano
Keyword(s):  
Morphological Characteristics ◽  
Pollen Grains ◽  
Rare Occurrence ◽  
Araucaria Angustifolia ◽  
Conifer Species ◽  
Normal Morphology ◽  
Male And Female ◽  
Reproductive Structures ◽  
Morphological Aspects ◽  
Adult Trees

Araucaria angustifolia (Bert.) O. Kuntze is a dioecious conifer species native of Brazil. The rare occurrence of monoiceous specimens have been attributed to pathogenic infections or other injuries in adult trees. Here, the morphological characteristics of male and female cones and pollen grains of a monoiceous A. angustifolia are described. Male and female cones and pollen grains presented normal morphology, lacking any sort of injuries or infection and suggesting the existence of further grounds for the occurrence of monoicy in this conifer species.

scholarly journals Morphological Characteristics, Fruit Qualities and Evaluation of Reproductive Functions in Autotetraploid Satsuma Mandarin (Citrus unshiu Marcow)

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2441
Author(s):  
Miki Sudo ◽  
Kiichi Yasuda ◽  
Masaki Yahata ◽  
Mai Sato ◽  
Akiyoshi Tominaga ◽  
...  
Keyword(s):  
Reproductive Potential ◽  
Morphological Characteristics ◽  
Pollen Grains ◽  
Fruit Weight ◽  
Citrus Unshiu ◽  
Male And Female ◽  
Reciprocal Crosses ◽  
Satsuma Mandarin ◽  
Seedless Fruits

The morphological characteristics and fruit quality of an autotetraploid plant selected from nucellar seedlings of Satsuma mandarin (Citrus unshiu Marcow.) were investigated. Additionally, in order to evaluate the reproductive potential of male and female gametes of the tetraploid Satsuma mandarin, reciprocal crosses with diploid cultivars were also carried out. The tetraploid had significantly thick and round leaves, as compared to those of the diploid Satsuma mandarin. The sizes of the flowers and pollen grains of the tetraploid were significantly larger than those of the diploid. Pollen fertility of tetraploid was high compared with that of the diploid. The tetraploid produced seedless fruits. The fruit weight of the tetraploid was equal to that of the diploid. Compared to the diploid fruits, the tetraploid fruit had less sugar contents and more organic acid contents. Although the tetraploid fruits showed similar traits to other Citrus tetraploids such as thick and hard peels, the tetraploid had a higher content of carotenoids in the flavedo than the diploid, and the rind color of the tetraploid was much better. In the reciprocal crosses between the tetraploid Satsuma mandarin and diploid cultivars, some seeds were obtained, and triploid progenies were obtained in all cross combinations.

Adaptation of male reproductive structures to wind pollination in gymnosperms: Cones and pollen grains

2011 ◽  
Vol 91 (5) ◽  
pp. 897-906 ◽  
Author(s):  
Y. Lu ◽  
B. Jin ◽  
L. Wang ◽  
Y. Wang ◽  
D. Wang ◽  
...  
Keyword(s):  
Pollen Dispersal ◽  
Digital Camera ◽  
Morphological Characteristics ◽  
Pollen Grains ◽  
Wind Pollination ◽  
Ancestral State ◽  
Physical Restraints ◽  
Pollination Success ◽  
Reproductive Structures ◽  
Evolutionary Response

Lu, Y., Jin, B., Wang, L., Wang, Y., Wang, D., Jiang, X.-X. and Chen, P. 2011. Adaptation of male reproductive structures to wind pollination in gymnosperms: Cones and pollen grains. Can. J. Plant Sci. 91: 897–906. Wind pollination (anemophily) in gymnosperms is thought to be an ancestral state. Previous studies considered wind pollination to be a largely random phenomenon, but recent evidence suggests that wind-pollinated species have evolved different complex reproductive adaptations for controlling and maximizing the success of wind pollination. However, compared with angiosperms, wind pollination in gymnosperms is poorly understood. We investigated the male reproductive structures of 13 representative gymnosperm species using a scanning electron microscope and digital camera, and analyzed how the morphological characteristics of male cones and pollen facilitate pollination. These characteristics showed a surprising variation between different gymnosperm species in improving pollination success. For example, the relationship between the position of the male cone and the surrounding vegetative structures is adjusted to optimize pollen release. The pollen grains have sacs and papilla and exhibit particular shapes after release from microsporangia, including boat-like, saccate, papilla-like and spheroid shapes, which facilitate pollen dispersal in the air. Taken together, our results suggest that the extensive diversity of male reproductive structures within gymnosperms represents an evolutionary response to long-term selection and results in solutions to the physical restraints of anemophily.

A case of gynandromorphism in Amblyomma mixtum (Acari, Ixodidae)

2017 ◽  
Vol 43 (2) ◽  
pp. 268
Author(s):  
Fredy A. Rivera-Páez ◽  
Marcelo B. Labruna ◽  
Thiago F. Martins ◽  
Bruno Rodrigues-Sampieri ◽  
María I. Camargo-Mathias
Keyword(s):  
Tick Species ◽  
Morphological Characteristics ◽  
Amblyomma Cajennense ◽  
Literature Report ◽  
Male And Female ◽  
Natural Infestation

Gynandromorphism is a condition in which an organism simultaneously exhibits male and female morphological characteristics. In Colombia, the taxon Amblyomma cajennense is represented by the species Amblyomma patinoi and Amblyomma mixtum. In September of 2014, in the Colombian Orinoco region, adult ticks were collected and determined from natural infections in bovines and equines. A gynandromorph was described from a natural infestation on a bovine, and morphologically classified as A. mixtum. This is the first literature report of a gynandromorph of A. mixtum, and the first description of a gynandromorph for a tick species in Colombia.

Developmental morphology and anatomy of the reproductive structures in sunflower (Helianthus annuus): a unified temporal scale

Botany ◽  
2015 ◽  
Vol 93 (5) ◽  
pp. 307-316 ◽  
Author(s):  
L.I. Lindström ◽  
L.F. Hernández
Keyword(s):  
Disease Resistance ◽  
Helianthus Annuus ◽  
Oil Content ◽  
Genetic Selection ◽  
Reproductive Development ◽  
Developmental Morphology ◽  
Male And Female ◽  
Reproductive Structures ◽  
Selection For ◽  
Growing Conditions

In sunflower (Helianthus annuus L.), there has been an intense genetic selection for achenes with agronomic value, such as greater mass, oil content, and disease resistance. However, the information regarding the anatomical events that control their growth and maturation is surprisingly scarce. The aim of the present work was to study sunflower male and female sporogenesis and gametogenesis, as well as cell division and enlargement and tissue differentiation in the ovary and the embryo, linking the timing of these events to two frequently used phenological scales and a thermal time scale. In addition, we propose an ontogenetic scale that integrates the results of the present work to that of previous studies on sunflower reproductive development. The unified scales presented here provide a framework for others to investigate the relationships uncovered in this study in different genetic backgrounds and under different growing conditions.

scholarly journals Post-hatching development of bovine embryos in vitro: the effects of tunnel preparation and gender

Zygote ◽  
2011 ◽  
Vol 20 (2) ◽  
pp. 123-134 ◽  
Author(s):  
Grazieli Marinheiro Machado ◽  
Ester Siqueira Caixeta ◽  
Carolina Madeira Lucci ◽  
Rodolfo Rumpf ◽  
Maurício Machaim Franco ◽  
...  
Keyword(s):  
Gene Expression ◽  
Morphological Characteristics ◽  
Tunnel Construction ◽  
Agarose Gel ◽  
Male And Female ◽  
Embryo Size ◽  
And Gender ◽  
Phosphate Buffered Saline ◽  
Kinetics Of

SummaryThe objective of this study was to compare morphological characteristics, kinetics of development, and gene expression of male and female IVP embryos that were cultured until day (D)15 (fertilization = D0), using either phosphate-buffered saline (PBS) or Milli-Q water (MQW) to dilute the agarose gel used for tunnel construction. On D11, embryos (n = 286) were placed in agarose gel tunnels diluted in PBS and MQW. Embryos were evaluated for morphology, and embryo size was recorded on D11, D12.5, D14 and D15. Then, embryos were sexed and used for gene expression analyses (G6PD, GLUT1, GLUT3, PGK1, PLAC8, KRT8, HSF1 and IFNT). The percentage of elongated embryos at D15 was higher (p < 0.05) in the PBS (54%) than in the MQW (42%) gel. However, embryos produced in MQW were bigger (p < 0.05) and had a lower expression of GLUT1 (p = 0.08) than those cultured in PBS. There was a higher proportion of male than female embryos at D15 in both treatments, MQW (65% vs. 35%; p < 0.05) and PBS (67% vs. 33%; p < 0.05); however, embryo size was not significantly different between genders. Moreover, D15 female embryos had greater expression of G6PD (p = 0.05) and KRT8 (p = 0.03) than male embryos. In conclusion, the diluent used for tunnel construction affected embryo development in the post-hatching development (PHD) system, and the use of MQW was the most indicative measure for the evaluation of embryo quality. Male and female embryos cultured from D11 to D15, either in an MQW or PBS agarose gel, demonstrated similar development but different gene expression.

scholarly journals Effects of herbivory and its timing on reproductive success of a tropical deciduous tree

2020 ◽  
Vol 126 (5) ◽  
pp. 957-969
Author(s):  
Enya N Quiroz-Pacheco ◽  
Francisco Mora ◽  
Karina Boege ◽  
César A Domínguez ◽  
Ek del-Val
Keyword(s):  
Reproductive Success ◽  
Structural Equation ◽  
Structural Equation Models ◽  
Pollen Grains ◽  
Leaf Damage ◽  
Deciduous Tree ◽  
Herbivore Damage ◽  
Male And Female ◽  
Foliar Damage ◽  
The Impact

Abstract Background and Aims The implications of herbivory for plant reproduction have been widely studied; however, the relationship of defoliation and reproductive success is not linear, as there are many interacting factors that may influence reproductive responses to herbivore damage. In this study we aimed to disentangle how the timing of foliar damage impacts both male and female components of fitness, and to assess when it has greater impacts on plant reproductive success. Methods We measured herbivore damage and its effects on floral production, male and female floral attributes as well as fruit yield in three different phenological phases of Casearia nitida (Salicaceae) over the course of two consecutive years. Then we tested two models of multiple causal links among herbivory and reproductive success using piecewise structural equation models. Key Results The effects of leaf damage differed between reproductive seasons and between male and female components of fitness. Moreover, the impact of herbivory extended beyond the year when it was exerted. The previous season’s cumulated foliar damage had the largest impact on reproductive characters, in particular a negative effect on the numbers of inflorescences, flowers and pollen grains, indirectly affecting the numbers of infructescences and fruits, and a positive one on the amount of foliar damage during flowering. Conclusions For perennial and proleptic species, the dynamics of resource acquisition and allocation patterns for reproduction promote and extend the effects of herbivore damage to longer periods than a single reproductive event and growing season, through the interactions among different components of female and male fitness.

scholarly journals Transformation of Seed Non-Transmissible Hop Viroids in Nicotiana benthamiana Causes Distortions in Male Gametophyte Development

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2398
Author(s):  
Lenka Steinbachová ◽  
Jaroslav Matoušek ◽  
Gerhard Steger ◽  
Helena Matoušková ◽  
Sebastjan Radišek ◽  
...  
Keyword(s):  
Nicotiana Benthamiana ◽  
Male Gametophyte ◽  
Pollen Grains ◽  
Potato Spindle Tuber Viroid ◽  
Apple Fruit ◽  
Mature Pollen ◽  
Rare Occurrence ◽  
Gametophyte Development ◽  
Male Gametophyte Development ◽  
Marker Proteins

Viroids are small, non-coding, parasitic RNAs that promote developmental distortions in sensitive plants. We analyzed pollen of Nicotiana benthamiana after infection and/or ectopic transformation with cDNAs of citrus bark cracking viroid (CBCVd), apple fruit crinkle viroid (AFCVd) and potato spindle tuber viroid (PSTVd) variant AS1. These viroids were seed non-transmissible in N. benthamiana. All viroids propagated to high levels in immature anthers similar to leaves, while their levels were drastically reduced by approximately 3.6 × 103, 800 and 59 times in mature pollen of CBCVd, AFCVd and PSTVd infected N. benthamiana, respectively, in comparison to leaves. These results suggest similar elimination processes during male gametophyte development as in the Nicotiana tabacum we presented in our previous study. Mature pollen of N. benthamiana showed no apparent defects in infected plants although all three viroids induced strong pathological symptoms on leaves. While Nicotiana species have naturally bicellular mature pollen, we noted a rare occurrence of mature pollen with three nuclei in CBCVd-infected N. benthamiana. Changes in the expression of ribosomal marker proteins in AFCVd-infected pollen were detected, suggesting some changes in pollen metabolism. N. benthamiana transformed with 35S-driven viroid cDNAs showed strong symptoms including defects in pollen development. A large number of aborted pollen (34% and 62%) and a slight increase of young pollen grains (8% and 15%) were found in mature pollen of AFCVd and CBCVd transformants, respectively, in comparison to control plants (3.9% aborted pollen and 0.3% young pollen). Moreover, pollen grains with malformed nuclei or trinuclear pollen were found in CBCVd-transformed plants. Our results suggest that “forcing” overexpression of seed non-transmissible viroid led to strong pollen pathogenesis. Viroid adaptation to pollen metabolism can be assumed as an important factor for viroid transmissibility through pollen and seeds.

scholarly journals Frequency of mandibular third molar surgical impactions in orthodontic patients with different antegonial notching

2019 ◽  
Vol 8 (3) ◽  
pp. 112-116
Author(s):  
Muhammad Azeem ◽  
Muhammad Mudassar Saleem ◽  
Zubair Hassan Awaisi ◽  
Muhammad Imran Saleh ◽  
Zubair Ahmed ◽  
...  
Keyword(s):  
Third Molar ◽  
Morphological Characteristics ◽  
P Value ◽  
Third Molars ◽  
Cross Sectional ◽  
Male And Female ◽  
Mandibular Third Molar ◽  
Orthodontic Patients ◽  
Inferior Border ◽  
Medical University

Background: Few studies have been reported so far on the frequency of lower third molar impactions in patients with different morphological characteristics. Our aim in this study was to find out the frequency of impacted lower third molars in orthodontic patients with different antegonial notch depths. Material and Methods: This cross-sectional research was conducted at Orthodontics Department of Dental Section, Faisalabad Medical University, Faisalabad, and de’Montmorency College of Dentistry, Lahore, Pakistan from June 2017 to June 2019. A total of 60 orthopantomograms (OPGs) of patients with impacted lower third molars were included. The depth of antegonial notch was calculated on all the selected OPGs by measuring distance between the deepest area of the notch cavity and the tangent on the inferior border of the mandible. The patients with depth of antegonial notch of 1 mm or less were labeled as having shallow antegonial notch, while those with 3 mm or more were considered as having deep antegonial notch. Percentages and mean + SD were calculated for different variables. Depth of antegonial notching was compared between genders using ANOVA with P-value <0.5 considered as significant. Results: Of 60 orthodontic patients, there was an equal number of male and female patients (n=30). The average age of the patients was 25.5±4 years. Overall frequency of impactions was similar in both the genders and frequency of impacted lower third molars was found to be greater in patients with deeper antegonial notches. Conclusion: Mandibular third molar impactions were most frequent in orthodontic patients with deep antegonial notches

scholarly journals Studies on the Pollination Characteristics and Pollination Level of Chinese fir Seed Orchard

2004 ◽  
Vol 53 (1-6) ◽  
pp. 7-11 ◽  
Author(s):  
Z. Zhuowen
Keyword(s):  
Accumulation Rate ◽  
Pollen Grains ◽  
Seed Orchard ◽  
Distribution Patterns ◽  
Chinese Fir ◽  
Female Cone ◽  
Bottom Part ◽  
Male And Female ◽  
Seed Orchards ◽  
Male Cone

Abstract Data from three seed orchards (Chongyang, Zhangle and Laoshan) and Lintian forest were used to study pollination characteristics, pollination level, pollen and ovule production in Chinese fir. The results show that male and female cones have their own distribution patterns within crowns. Male cones are located in the middle to top and female cones the middle to bottom part of the crown. Because of lower density of trees in seed orchard than that in a stand, female cones are distributed over the entire crown in seed orchard trees. Chinese fir male and female cones appear to be very well adapted for wind as the pollination mechanism. There is no difference in the number of pollen grains produced by one pollen sac among trees in the same clone, but there are differences between clones. There are differences between both clones and years in female cone number, male cone number and their ratio. The pollen accumulation rate during pollination should be 3 to 5 pollen grains/mm2 to ensure fertilization. The Chinese fir seed orchards in this study produced too much pollen and could be improved by stimulation of more female flowers in order to produce more seeds.

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