scholarly journals Calculation of the ovule number in the genus Salix : A method for taxa differentiation

2021 ◽  
Author(s):  
Аlexander M. Marchenko ◽  
Yulia A. Kuzovkina
Keyword(s):  
Ovule Number

Ovule number per flower in a world of unpredictable pollination

2009 ◽  
Vol 96 (6) ◽  
pp. 1159-1167 ◽  
Author(s):  
Martin Burd ◽  
Tia-Lynn Ashman ◽  
Diane R. Campbell ◽  
Michele R. Dudash ◽  
Mark O. Johnston ◽  
...  
Keyword(s):  
Ovule Number

scholarly journals A DIRECTIONAL CLINE IN MOURIRI GUIANENSIS (MELASTOMATACEAE)

1983 ◽  
Vol 13 (5-6) ◽  
pp. 799-811
Author(s):  
Thomas Morley ◽  
Keyword(s):  
Distribution Pattern ◽  
Climatic Change ◽  
Morphological Variation ◽  
Rio De Janeiro ◽  
Leaf Blade ◽  
Petiole Length ◽  
West Central ◽  
Central Amazonia ◽  
Ovule Number ◽  
Rainfall Patterns

Abstract Morphological variation in Mouriri guianensis is described and analyzed throughout its range in Brazil and adjacent regions. Features that vary are ovary size, locule and ovule number, shape and smoothness of the leaf blade and petiole length. The largest ovaries with the most ovules occur in west central Amazonia; intermediate sizes and numbers are widespread but reach the coast only between Marajó and Ceará; and the smallest ovaries with the fewest locules and ovules are coastal or nearcoastal from Delta Amacuro in Venezuela to Marajó. Small ovaries also occur in coastal Alagoas and at Rio de Janeiro. Ovaries with the fewest locules and ovules are believed to be the most specialized, the result of evolution toward decreased waste of ovules, since the fruits of all members are few-seeded. Leaf characters correlate statistically with ovule numbers. Possible origen of the distribution pattern of the species is compared in terms of present rainfall patterns and in terms of Pleistocene climatic change with associated forest refuges. It is concluded that both phenomena were probably influential. High specialization appears to have accompanied isolation, for reasons that are unclear. Because the plants from Delta Amacuro to Marajó are the most specialized they may once have been more isolated than now.

scholarly journals Gibberellins negatively modulate ovule number in plants

Development ◽  
2018 ◽  
Vol 145 (13) ◽  
pp. dev163865 ◽  
Author(s):  
Maria D. Gomez ◽  
Daniela Barro-Trastoy ◽  
Ernesto Escoms ◽  
Maite Saura-Sánchez ◽  
Ines Sánchez ◽  
...  
Keyword(s):  
Ovule Number

Morphotypic Differentiation in the South-Western Australian Restiad Lyginia barbata R.Br (Restionaceae)

1993 ◽  
Vol 41 (1) ◽  
pp. 91 ◽  
Author(s):  
TL Bell ◽  
JS Pate
Keyword(s):  
Growth Rates ◽  
Dry Matter ◽  
The Other ◽  
Spikelet Number ◽  
Male And Female ◽  
First Reproduction ◽  
Ovule Number ◽  
Culm Density ◽  
Rhizome Morphology ◽  
Western Australian

Study of Lyginia barbata across its distribution range in south-western Australia identified five distinctive morphotypes, viz. a tall-culmed, densely tufted fire-sensitive obligate seeder (S morphotype), a tall densely tufted fire-resistant resprouter (R1), a short flexuose-culmed, tufted resprouter (R2), a weakly clonal, semi-tufted resprouter (R3) and a short-culmed, widely spreading clonal form (R4). There was little variation within a morphotype between habitat locations and no evidence of intergrading of cohabiting morphotypes. Morphotype-specific differences were observed in culm height, rhizome morphology, culm density and spikelet morphology. Differences in reproductive biology related to the time of first reproduction in juvenile recruits, spikelet number per male and female culm, ovule number per female culm and seed : ovule ratio. Differences of a physiological nature were observed in seedling growth rates and proportional biomass (dry matter) allocations to culms, rhizomes, spikelets and seeds. Comparative quantitative scorings of the above features according to concepts of r- and K-selection rated the S form strongly r-selected, the R4 form equally strongly K-selected and the other forms (R1, R2 and R3) intermediate and with the R1 form possibly more r-selected than the others. It is suggested that the data provide a basis on which future taxonomic decisions regarding the taxon might be made.

scholarly journals Gynoecium size and ovule number are interconnected traits that impact seed yield

2020 ◽  
Vol 71 (9) ◽  
pp. 2479-2489 ◽  
Author(s):  
Mara Cucinotta ◽  
Maurizio Di Marzo ◽  
Andrea Guazzotti ◽  
Stefan de Folter ◽  
Martin M Kater ◽  
...  
Keyword(s):  
Seed Yield ◽  
Gene Regulatory Networks ◽  
Regulatory Networks ◽  
Current Knowledge ◽  
Fine Tuning ◽  
World Population ◽  
Meristematic Tissue ◽  
Reproductive Part ◽  
Ovule Number ◽  
Gene Regulatory

Abstract Angiosperms form the largest group of land plants and display an astonishing diversity of floral structures. The development of flowers greatly contributed to the evolutionary success of the angiosperms as they guarantee efficient reproduction with the help of either biotic or abiotic vectors. The female reproductive part of the flower is the gynoecium (also called pistil). Ovules arise from meristematic tissue within the gynoecium. Upon fertilization, these ovules develop into seeds while the gynoecium turns into a fruit. Gene regulatory networks involving transcription factors and hormonal communication regulate ovule primordium initiation, spacing on the placenta, and development. Ovule number and gynoecium size are usually correlated and several genetic factors that impact these traits have been identified. Understanding and fine-tuning the gene regulatory networks influencing ovule number and pistil length open up strategies for crop yield improvement, which is pivotal in light of a rapidly growing world population. In this review, we present an overview of the current knowledge of the genes and hormones involved in determining ovule number and gynoecium size. We propose a model for the gene regulatory network that guides the developmental processes that determine seed yield.

Temporal patterns of gamete production within individuals of Raphanus sativus (Brassicaceae)

1990 ◽  
Vol 68 (3) ◽  
pp. 480-486 ◽  
Author(s):  
Helen J. Young ◽  
Maureen L. Stanton
Keyword(s):  
Raphanus Sativus ◽  
Female Parent ◽  
Temporal Patterns ◽  
Developmental Differences ◽  
Pollen Size ◽  
Male And Female ◽  
Ovule Number ◽  
Pollen Number ◽  
Gamete Production ◽  
Phenotypic Gender

Previous studies on the deployment of energy to male and female gametes in plants have concentrated on differences among individuals or among related species. We documented temporal patterns of sex allocation within individual wild radish plants grown under controlled conditions. Lifetime investments in pollen and ovules were determined for four unrelated individuals of Raphanus sativus L. (Brassicaceae). Each individual produced 600–1100 flowers over the approximately 5-week flowering period. Mature floral buds were collected daily and ovule number, pollen grain number, pollen size, and pollen to ovule ratio (P:O) were determined for each. Variation in these traits was partitioned into variation among plants and among dates (representing flowering sequence). There was significant variation among plants for all characters, but because plants responded differently to date for three of the characters, further analyses were performed on a plant-by-plant basis. All plants showed significant reductions in pollen number and P:O through time, three plants showed a significant reduction in pollen size with time, and two plants showed a significant reduction in ovule number with time. The observed variation in phenotypic gender among these plants was not environmentally mediated because all plants were grown together in a controlled environment and therefore the differences in allocation to gametes were due to genetic or developmental differences. A result of intraspecific variation in gamete production is that the success of each individual as a male and female parent is likely to vary both within the population and within the flowering season. Key words: pollen to ovule ratio, Raphanus, pollen number, temporal changes, phenotypic gender, Brassicaceae, radish.

VARIABILITY OF SEED-SET IN ALFALFA AND CORRELATIONS WITH SOME POLLEN AND OVULE CHARACTERISTICS

1981 ◽  
Vol 61 (2) ◽  
pp. 319-323 ◽  
Author(s):  
R. Y. GURGIS ◽  
D. E. ROWE
Keyword(s):  
Seed Set ◽  
Pollen Viability ◽  
Genetic Material ◽  
Tube Length ◽  
Paternal Effects ◽  
Ovule Number ◽  
High Heritability ◽  
Paternal Parent ◽  
The Difference ◽  
Germinated Pollen

A random sample of 30 named alfalfa (Medicago sativa L.) cultivars representing diverse genetic material was investigated for relationships among the following traits: frequency of seed-set (seeds per flower) after self-pollination, frequency of seed-set after cross-pollination, abundance of pollen, viability of pollen, germinated pollen tube length, ovule number, and ovule size. In each cultivar, 100 reciprocal crosses and selfs were made by hand in the greenhouse, with emasculation when appropriate. A second experiment re-used the plants of 11 cultivars for specific inter- and intra-cultivar crosses to estimate the relative importance of maternal and paternal effects on seed-set. In the first experiment, seed-set of crosses did not correlate with any other factors, and the seed-set of selfs was only slightly correlated with pollen viability. An analysis of broad sense heritabilities indicated a very low heritability for seed-set of selfs (H = 0.11), and relatively high heritability for seed-set of crosses (H = 0.74). The difference in rates of seed-set for crosses and selfs on the same plant also had high heritability (H = 0.66). The mechanisms controlling seed-set with selfing and with crossing appeared to be different. In the second experiment, correlation analysis indicated that the maternal parent had over five times the influence of the paternal parent on the frequency of seed-set.

Development and evolution of the gynoecium in Myrteae (Myrtaceae)

2014 ◽  
Vol 62 (4) ◽  
pp. 335 ◽  
Author(s):  
Rafael R. Pimentel ◽  
Natália P. Barreira ◽  
Diego P. Spala ◽  
Nathane B. Cardim ◽  
Marcelo C. Souza ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Floral Anatomy ◽  
Structural Diversity ◽  
Morphological Characters ◽  
Fleshy Fruit ◽  
South American ◽  
Transmission Electron ◽  
History Of ◽  
Ovule Number ◽  
Development And Evolution

Characters of the gynoecium are considered potentially significant for the systematics of Myrtaceae. However, only two such characters – ovule number and placentation – have been addressed from an evolutionary perspective. Colleter presence in flowers is a synapomorphy of Myrtales; however, no morphological and histochemical descriptions of such structures have been done in Myrtaceae. Here we analysed the ontogeny and anatomy of the gynoecium combined with the ontogeny, anatomy, ultrastructure, and histochemistry of the colleters to study the evolution of these characters and map their states in the Myrteae phylogenetic tree. Our findings may help elucidate the evolutionary history of this tribe of fleshy-fruit producers so important towards maintaining ecological balance in the rainforest. Floral anatomy and ontogeny were analysed using light microscopy. Colleter samples were processed using standard methods for light and transmission electron microscopy. The main metabolites in colleters were detected via histochemistry. To map character states the program Mesquite version 2.71 was used. The morphological characters of the South American Myrteae here analysed provided an overview of the evolution of gynoecium – with cauline or carpellate placenta – and of colleters, as well as synapomorphies for the clades Plinia + Myrcia and Eugenia + Pimenta. The presence of two integuments in the ovules associated with sclereids and colleters in the gynoecium and the young fleshy fruit assures the efficient dispersal of their seeds. Our findings regarding gynoecium structural diversity of the tribe Myrteae give a new insight on their morphologically uniform flowers.

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