Floral phenology in relation to pollination and reproductive output in Commelina caroliniana (Commelinaceae)

2008 ◽  
Vol 56 (1) ◽  
pp. 59 ◽  
Author(s):  
Veenu Kaul ◽  
A. K. Koul
Keyword(s):  
Rainy Season ◽  
Reproductive Output ◽  
Seed Set ◽  
Floral Biology ◽  
The Third ◽  
Cross Pollination ◽  
Large Numbers ◽  
Floral Phenology ◽  
Self Compatibility ◽  
Fruit And Seed Set

Commelina caroliniana Walter is an andromonoecious rainy-season weed. It bears staminate and hermaphrodite flowers in spathes. In some spathes, structurally hermaphrodite flowers of the third and fourth orders function either as male or female. The flowers are structured for cross-pollination. Events of floral biology suggest weak protandry which also contributes to cross-pollination. Large numbers of hymenopterans (nine species) visited the flowers and transferred pollen to stigmas. Whenever cross-pollination failed, selfing took over. Auto-fertility and self-compatibility indices revealed that the plants were self-compatible. Only some flowers of the third and fourth orders within a spathe were partially self-compatible. These facts notwithstanding, manual cross-pollination of flowers yields increased fruit and seed set.

Floral and pollination biology of three sympatric Vaccinium (Ericaceae) species in the Upper Ardennes, Belgium

1996 ◽  
Vol 74 (2) ◽  
pp. 210-221 ◽  
Author(s):  
A. -L. Jacquemart ◽  
J. D. Thompson
Keyword(s):  
Mating System ◽  
Related Species ◽  
Seed Set ◽  
Floral Biology ◽  
Floral Traits ◽  
Mixed Mating ◽  
Mixed Mating System ◽  
Closely Related Species ◽  
Fruit And Seed Set ◽  
Selfing Ability

Comparative studies of the reproductive biology and pollination ecology of closely related species allow us to test several ideas related to the evolution of selfing taxa from outcrossing ancestors. The existence of closely related species in the same habitat provides a particularly useful opportunity to examine this issue. A variety of floral traits likely to be associated with the reproductive system of three sympatric Vaccinium species (V. myrtillus, V. vitis-idaea, and V. uliginosum) were quantified in a heathland in the Upper Ardennes, Belgium. These traits included the length and width of the corolla, the number and size of the anthers, the number of pollen tetrads and ovules, and the length of the style. Pollen to ovule ratios suggest a mixed mating system in the three species. The greater pollen to ovule ratio and stigma–anther separation in V. vitis-idaea suggest that it functions more as an outcrosser than the two congeners. The effects of caging, emasculation, and artificial pollination on fruit and seed set differed among years and among the three species. Supplementary pollination increased fruit set and fruit characteristics (particularly seed number) relative to natural pollination in the three species. The three species showed a varied but poor capacity to self in the absence of pollinators. Seed set per fruit was lower in the spontaneously selfed flowers in comparison with hand-crossed pollinated flowers in V. myrtillus and V. vitis-idaea but not in V. uliginosum. This higher ability to self in V. uliginosum indicates a lower capacity to self in the absence of pollinators. However, all the three species were at least partially self-compatible. Together the floral traits and selfing ability suggest that the polyploid V. uliginosum appears to be more highly selfing than the two diploids, particularly V. vitis-idaea. Keywords: floral biology, mixed mating, mating system, Vaccinium, seed set.

scholarly journals Self-Compatibility and Reproductive Success of Oenothera drummondii subsp. drummondii: Is It Similar between Native and Non-Native Populations?

Diversity ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 431
Author(s):  
Juan B. Gallego-Fernández ◽  
José G. García-Franco
Keyword(s):  
Reproductive Success ◽  
Fruit Set ◽  
Seed Set ◽  
Fruit Weight ◽  
Clinal Variation ◽  
Native Range ◽  
Cross Pollination ◽  
Native Populations ◽  
Self Compatibility ◽  
Selection Factors

The mating system of plants widely distributed can change in native range but also in non-native habitats. Oenothera drummondii, native to the coastal dunes of the Gulf of Mexico, has been introduced to Europe, Africa, Asia and Oceania. Hand self- and cross-pollination were performed to determine compatibility and to compare fruit set, fruit weight, seed set and germination characteristics from natives and non-natives populations and a comprehensive integral reproductive success index (IRSI) was built. Oenothera drummondii exhibited high self-compatibility and mixed reproductive systems in all populations. Characteristics of fruits and seeds from self- and cross-pollination varied within and between native and non-native populations and some had a positive clinal variation in the native range. The IRSI was sensitive to changes of fruit set, seed set and final germination of both self- and cross-pollination, showing differences between native populations. Differences in characteristics of fruits and seeds in the native and non-native ranges suggest the occurrence of distinct selection factors. The mixed reproductive system of O. drummondii suggests it can take advantage of local visitors in the native range, but also can provide advantages for the establishment at non-native sites giving the opportunity to interact with local flower visitors.

Self-compatibility and floral biology in subdioecious Wurmbea dioica (Colchicaceae)

2003 ◽  
Vol 51 (1) ◽  
pp. 39 ◽  
Author(s):  
Glenda Vaughton ◽  
Mike Ramsey
Keyword(s):  
Inbreeding Depression ◽  
Seed Set ◽  
Developmental Stages ◽  
Floral Biology ◽  
Seed Abortion ◽  
Temporal Separation ◽  
Gender Dimorphism ◽  
Genetic Method ◽  
Floral Longevity ◽  
Self Compatibility

Dioecy has long been interpreted as a mechanism to avoid self-fertilisation and the negative effects of inbreeding depression. We determined relative self-compatibility and temporal overlap of male and female functions for hermaphrodites in subdioecious Wurmbea dioica to assess the role of selfing in the maintenance of gender dimorphism. Plants were self-compatible but did not self-pollinate autonomously. Self- and open-pollinated hermaphrodites had high seed abortion and low seed set, whereas crossed hermaphrodites and crossed and open females had low seed abortion and high seed set. For selfed hermaphrodites, abortion occurred over a range of developmental stages and was negatively related to seed set. Inbreeding depression for seed set varied extensively among plants, averaging 0.56. Despite high inbreeding depression, substantial selfing occurred in open-pollinated hermaphrodites (S = 0.76), as estimated by a non-genetic method. Flowers were protogynous, although temporal separation of male and females functions was limited because anthers began to dehisce shortly after flowers opened. Anther dehiscence was staggered over 4 days and floral longevity, pollen longevity and stigma receptivity were prolonged, thus providing considerable opportunities for pollinator-mediated self-pollination. Our findings indicate that high levels of selfing and subsequent abortion of selfed embryos due to early acting inbreeding depression are important factors maintaining gender dimorphism in W. dioica.

Assyria

2018 ◽  
Author(s):  
David M. Lewis
Keyword(s):  
The Third ◽  
Debt Bondage ◽  
Large Numbers ◽  
Widespread Phenomenon ◽  
Economic Position ◽  
Tenant Farmers ◽  
Legal Understanding

This chapter explores the archival texts of the Neo-Assyrian Empire and attempts to gauge the legal and economic position of slavery in Assyrian society. It shows that the Assyrians held a similar legal understanding of slavery to the Greeks, and knew also of the phenomenon of debt bondage. The chapter then moves on to consider the location of slavery in Assyrian society, showing widespread and significant levels of slave ownership among the Assyrian elite; however, relatively high slave prices prevented slave ownership from becoming a more widespread phenomenon. The third part of the chapter looks at the Assyrian countryside more broadly, and shows that despite often owning large numbers of slaves, members of the Assyrian elite more probably drew the bulk of their income from the exploitation of bound tenant farmers.

Introduction

2018 ◽  
Author(s):  
Tim Lewens
Keyword(s):  
Social Sciences ◽  
Human Nature ◽  
Potential Functions ◽  
Human Psychology ◽  
Human Culture ◽  
The Third ◽  
Current State ◽  
Large Numbers ◽  
The Social ◽  
Compare And Contrast

Many evolutionary theorists have enthusiastically embraced human nature, but large numbers of evolutionists have also rejected it. It is also important to recognize the nuanced views on human nature that come from the side of the social sciences. This introduction provides an overview of the current state of the human nature debate, from the anti-essentialist consensus to the possibility of a Gray’s Anatomy of human psychology. Three potential functions for the notion of species nature are identified. The first is diagnostic, assigning an organism to the correct species. The second is species-comparative, allowing us to compare and contrast different species. The third function is contrastive, establishing human nature as a foil for human culture. The Introduction concludes with a brief synopsis of each chapter.

scholarly journals Phloem-Feeding Herbivores Affect Floral Development and Reproduction in the Etruscan Honeysuckle (Lonicera etrusca Santi)

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 815
Author(s):  
Sandra V. Rojas-Nossa ◽  
José María Sánchez ◽  
Luis Navarro
Keyword(s):  
Fruit Set ◽  
Floral Development ◽  
Seed Set ◽  
Wild Populations ◽  
Ecological Processes ◽  
Trade Offs ◽  
Complex Landscape ◽  
Fruit And Seed Set ◽  
Phloem Feeding ◽  
Growth And Reproduction

Floral development depends on multifactor processes related to genetic, physiological, and ecological pathways. Plants respond to herbivores by activating mechanisms aimed at tolerating, compensating, or avoiding loss of biomass and nutrients, and thereby survive in a complex landscape of interactions. Thus, plants need to overcome trade-offs between development, growth, and reproduction vs. the initiation of anti-herbivore defences. This study aims to assess the frequency of phloem-feeding herbivores in wild populations of the Etruscan honeysuckle (Lonicera etrusca Santi) and study their effects on floral development and reproduction. The incidence of herbivory by the honeysuckle aphid (Hyadaphis passerinii del Guercio) was assessed in three wild populations of the Iberian Peninsula. The effect of herbivory on floral morphology, micromorphology of stigmas and pollen, floral rewards, pollination, and fruit and seed set were studied. The herbivory by aphids reduces the size of flowers and pollen. Additionally, it stops nectar synthesis and causes malformation in pollen and microstructures of stigmas, affecting pollination. As a consequence, fruit set and seed weight are reduced. This work provides evidence of the changes induced by phloem-feeding herbivores in floral development and functioning that affect the ecological processes necessary to maintain the reproductive success of plants.

scholarly journals A nonS-locus F-box gene breaks self-incompatibility in diploid potatoes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ling Ma ◽  
Chunzhi Zhang ◽  
Bo Zhang ◽  
Fei Tang ◽  
Futing Li ◽  
...  
Keyword(s):  
Potato Breeding ◽  
Inbred Lines ◽  
Hybrid Breeding ◽  
Self Incompatibility ◽  
Diploid Hybrid ◽  
Food Crop ◽  
Global Food Security ◽  
The Third ◽  
Self Compatibility ◽  
Global Food

AbstractPotato is the third most important staple food crop. To address challenges associated with global food security, a hybrid potato breeding system, aimed at converting potato from a tuber-propagated tetraploid crop into a seed-propagated diploid crop through crossing inbred lines, is under development. However, given that most diploid potatoes are self-incompatible, this represents a major obstacle which needs to be addressed in order to develop inbred lines. Here, we report on a self-compatible diploid potato, RH89-039-16 (RH), which can efficiently induce a mating transition from self-incompatibility to self-compatibility, when crossed to self-incompatible lines. We identify the S-locusinhibitor (Sli) gene in RH, capable of interacting with multiple allelic variants of the pistil-specific S-ribonucleases (S-RNases). Further, Sli gene functions like a general S-RNase inhibitor, to impart SC to RH and other self-incompatible potatoes. Discovery of Sli now offers a path forward for the diploid hybrid breeding program.

Pollination ecology of Caryocar brasiliense (Caryocaraceae) in Central Brazil cerrado vegetation

1993 ◽  
Vol 9 (2) ◽  
pp. 199-211 ◽  
Author(s):  
Rogério Gribel ◽  
John D. Hay
Keyword(s):  
Breeding System ◽  
Fruit Set ◽  
Seed Set ◽  
Floral Biology ◽  
Cerrado Vegetation ◽  
Central Brazil ◽  
Glossophaga Soricina ◽  
Caryocar Brasiliense ◽  
Anoura Geoffroyi ◽  
Phyllostomus Discolor

ABSTRACTThe floral biology, breeding system and pollination of Caryocar brasiliense were studied in the cerrado vegetation of Central Brazil. The large, yellowish-cream, brush-like flowers are pollinated mainly by glossophagine bats (Glossophaga soricina and Anoura geoffroyi). Three non-glossophagine bats (Phyllostomus discolor, Vampyrops lineatus and Carollia perspicillata) and two short probosisced hawk moths (Erinyis ello and Pseudosphinx tetrio) may also act as occasional pollinators. Caryocar brasiliense is self-compatible although it sets significantly more fruits when crossed than when selfed. The natural fruit set (fruit/flower ratio) and seed set (seed/ovule ratio) are 3.1% and 1.0% respectively. Most of the fruits and seeds are formed through the action of the flower visitors, despite the fact that about 20% of the non-visited flowers receive self pollen on at least one stigma.

scholarly journals Pollination of two species of Vellozia (Velloziaceae) from high-altitude quartzitic grasslands, Brazil

2007 ◽  
Vol 21 (2) ◽  
pp. 325-333 ◽  
Author(s):  
Claudia Maria Jacobi ◽  
Mário César Laboissiérè del Sarto
Keyword(s):  
High Altitude ◽  
Pollen Limitation ◽  
Cross Pollination ◽  
Se Brazil ◽  
Self Compatibility ◽  
Leaf Cutting ◽  
Pollen Theft ◽  
Floral Displays ◽  
Facultative Xenogamy ◽  
And Control

The pollinators and breeding system of two species of Vellozia (Velloziaceae) from high-altitude quartzitic grasslands in SE Brazil were studied. Vellozia leptopetala is shrubby and grows solely on rocky outcrops, V. epidendroides is herbaceous and grows on stony soils. Both bear solitary, hermaphrodite flowers, and have massive, short-lasting annual blooms. We evaluated the level of self-compatibility and need for pollinators of 50 plants of each species and 20-60 flowers per treatment: hand self- and cross-pollination, spontaneous pollination, agamospermy and control. The behavior of floral visitors on flowers and within plants was recorded. Both species are mostly self-incompatible, but produce a small number of seeds by self-fertilization. The pollen-ovule ratio suggests facultative xenogamy. They were visited primarily by bees, of which the most important pollinators were two leaf-cutting bees (Megachile spp.). Vellozia leptopetala was also pollinated by a territorial hummingbird. Low natural seed production compared to cross-pollination seed numbers suggests that pollen limitation is the main cause of low seed set. This was attributed to the combined effect of five mechanisms: selfing prior to anthesis, enhanced geitonogamy as a result of large floral displays, low number of visits per flower for the same reason, pollen theft by many insect species, and, in V. leptopetala, delivery of mixed pollen loads on the stigma as a consequence of hummingbird promiscuity.

CORRELATED RESPONSE IN BROWN SARSON

1970 ◽  
Vol 12 (4) ◽  
pp. 905-913 ◽  
Author(s):  
T. Swamy Rao
Keyword(s):  
Gamma Irradiation ◽  
Seed Set ◽  
Previous History ◽  
The Self ◽  
Correlated Response ◽  
History Of ◽  
Self Compatibility ◽  
Selection For ◽  
Direction Opposite ◽  
Brown Sarson

The correlated response with changes in self-compatibility in three varieties of brown sarson subjected to gamma irradiation was examined. Selection for improved seed set in the irradiated populations showed that substantial correlated response can result for a constellation of other characters in which the self-compatible and self-incompatible forms differ. The correlated response was in a direction opposite to that of the previous history of selection.

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