Reproductive biology in two Genisteae (Papilionoideae) endemic of the western Mediterranean region: Cytisus striatus and Retama sphaerocarpa

1999 ◽  
Vol 77 (6) ◽  
pp. 809-820 ◽  
Author(s):  
Tomás Rodríguez-Riaño ◽  
Ana Ortega-Olivencia ◽  
Juan A Devesa
Keyword(s):  
Reproductive Biology ◽  
Inbreeding Depression ◽  
Mediterranean Region ◽  
Seed Set ◽  
Western Mediterranean ◽  
Self Incompatibility ◽  
Retama Sphaerocarpa ◽  
Early Action ◽  
Fruit And Seed Set ◽  
Cytisus Striatus

We studied the reproductive biology of two leguminous shrubs endemic of the western Mediterranean region Cytisus striatus (Hill) Rothm. and Retama sphaerocarpa (L.) Boiss. The former is polliniferous, and the latter is nectariferous, with maximum nectar production at the earliest hours of the morning. Germination of the pollen grains in the flowers of the two species occurs only after rupture of the stigmatic surface. It is also necessary in both cases that pollinators (mainly Apis mellifera) visit the flowers for fruit and seed set to occur. A study of the pollen-pistil interaction indicated that there exists prezygotic self-incompatibility in these two species, probably of the gametophytic type, but some self-pollen tubes escape this control and self-fertilize some ovules. However, after hand self-pollination, fruit and seed set is very low for both species. This suggests the existence of a postzygotic rejection mechanism, which could be due either to the existence of late-acting self-incompatibility or to an early action of inbreeding depression, although there are lines of evidence that seem to point to the second possibility. Hand cross-pollination led to an increased number of fruit and seeds per plant relative to the control plants, indicating that reproduction is pollen limited.Key words: late-acting self-incompatibility, prezygotic self-incompatibility, fruit set, seed set, inbreeding depression, Spain.

The comparative reproductive biology of three Leucospermum species (Proteaceae) in relation to fire responses and breeding system

1985 ◽  
Vol 33 (2) ◽  
pp. 139 ◽  
Author(s):  
B Lamont
Keyword(s):  
Reproductive Biology ◽  
Breeding System ◽  
Reproductive Effort ◽  
Seed Set ◽  
Sugar Concentration ◽  
Self Incompatibility ◽  
Nectar Volume ◽  
Cultivated Populations ◽  
Ecological Range

A study was made of both natural and cultivated populations of the resprouter after fire, Leucospermum cuneiforme, and two non-sprouters, L. cordifolium and L. erubescens. Measurements included florets per head, heads per plant (on an absolute and volume basis), nectar volume and sugar concentration, seeds per head and seed set following bagging to prevent access to pollinators. The results provided almost no support for the hypothesis that, in comparison with non-sprouters, resprouters minimize their reproductive effort in association with self-incompatibility. There was, however, some support for earlier proposals that the most self-compatible species (in this case, L. cuneiforme) have the widest ecological range, the greatest reproductive effort and highest percentage seed set.

Self-incompatibility, Seed Abortion and Clonality in the Breeding Systems of Several Western Australian Drosera species (Droseraceae)

1997 ◽  
Vol 45 (1) ◽  
pp. 191 ◽  
Author(s):  
Helen M. Stace ◽  
Lin Chen ◽  
Sidney H. James
Keyword(s):  
Pollen Tube ◽  
Inbreeding Depression ◽  
Pollen Tube Growth ◽  
Sampling Method ◽  
Seed Set ◽  
Breeding Systems ◽  
Seed Abortion ◽  
Self Incompatibility ◽  
Position Effects ◽  
Western Australian

Western Australian Drosera L. species include one annualand many tuberous and pygmy perennials. In 20 species or subspecies, 17 taxawere self-incompatible (SI) and three were self-compatible (SC), as assessedby patterns of seed set and pollen tube growth. All SI species were clonal(tubers or gemmae), but two SC species were clonal (gemmae) and one wasannual. Self-pollen tube inhibition confirmed that SI species werepre-zygotically self-sterile. The sites of SI pollen tube inhibition variedfrom early (stigmatic) to late (stylar, placental, ovular), which suggestscontinuing evolution in the expression of the SI response. Self-compatiblespecies showed little inbreeding depression, but SI species showedconsiderable inbreeding depression as measured by seed abortion. In the threespecies tested, open-pollinated capsules were typically more fecund thanhand-pollinated capsules. In D. glanduligera Lehm., thismight represent position effects in an inflorescence that were reflected inthe sampling method. In other species, however, this might also reflectbiparental inbreeding depression in the glasshouse plants. Interspecificcrosses between D. tubaestylis N.Marchant & A.Lowrie(n = 14) and D. rosulataLehm. (n = 13) were slightly successful, with nopollen–pistil incompatibility interaction, but with extensive seedabortion. This is the first report of SI in Droseraceae.

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 Do s genes or deleterious recessives control late-acting self-incompatibility in Handroanthus heptaphyllus (Bignoniaceae)? A diallel study with four full sib progeny arrays

2021 ◽  
Author(s):  
Marta B Bianchi ◽  
Thomas R Meagher ◽  
Peter E Gibbs
Keyword(s):  
Genetic Control ◽  
Inbreeding Depression ◽  
Fruit Set ◽  
Genetic Model ◽  
Pollen Tubes ◽  
Self Incompatibility ◽  
Significant Difference ◽  
Partial Embryo ◽  
Ovule Penetration ◽  
S Genes

Abstract Background and Aims Genetically controlled self-incompatibility (SI) mechanisms constrain selfing and thus have contributed to the evolutionary diversity of flowering plants. In homomorphic gametophytic SI (GSI) and homomorphic sporophytic SI (SSI), genetic control is usually by a single multi-allelic locus S. Both GSI and SSI prevent self pollen tubes reaching the ovary and so are pre-zygotic in action. In contrast, in taxa with late-acting self-incompatibility (LSI), rejection is often post-zygotic, since self-pollen tubes grow to the ovary where fertilization may occur prior to floral abscission. Alternatively, lack of self fruit set could be due to early-acting inbreeding depression (EID). The aim of our study was to investigate mechanisms underlying lack of selfed fruit set in Handroanthus heptaphyllus in order to assess the likelihood of LSI versus EID. Methods We employed four full sib diallels to study the genetic control of LSI in Handroanthus heptaphyllus using a precociously flowering variant. We also used fluorescence microscopy to study the incidence of ovule penetration by pollen tubes in pistils that abscised following pollination or initiated fruits. Key Results All diallels showed reciprocally cross-incompatible full-sibs (RCI), reciprocally cross compatible full-sibs (RCC), and non-reciprocally compatible full-sibs (NRC) in almost equal proportions. There was no significant difference between the incidence of ovule penetrations in abscised pistils following self- and cross-incompatible pollinations, but those in successful cross pollinations were around twofold greater. Conclusions A genetic model postulating a single S locus with four s alleles, one of which, in the maternal parent, is dominant to the other three, will produce RCI, RCC and NRC situations each at 33 %, consistent with our diallel results. We favour this simple genetic control over an early-acting inbreeding depression (EID) explanation since none of our pollinations, successful or unsuccessful, resulted in partial embryo development, as would be expected under a whole genome EID effect.

Potential of Arabic documentary sources for reconstructing past climate in the western Mediterranean region from AD 680 to 1815

The Holocene ◽  
2021 ◽  
pp. 095968362110332
Author(s):  
Yassin Meklach ◽  
Chantal Camenisch ◽  
Abderrahmane Merzouki ◽  
Ricardo Garcia Herrera
Keyword(s):  
Spatial Resolution ◽  
Mediterranean Region ◽  
Climate Extremes ◽  
Western Mediterranean ◽  
Historical Documents ◽  
Atmospheric Conditions ◽  
Documentary Sources ◽  
Drought Conditions ◽  
Temporal And Spatial ◽  
Climate Proxies

Archival records and historical documents offer direct observation of weather and atmospheric conditions and have the highest temporal and spatial resolution, and precise dating, of the available climate proxies. They also provide information about variables such as temperature, precipitation and climate extremes, as well as floods, droughts and storms. The present work studied Arab-Islamic documentary sources covering the western Mediterranean region (documents written by Arab-Islamic historians that narrate social, political and religious history) available for the period AD 680–1815. They mostly provide information on hydrometeorological events. In Iberia the most intense droughts were reported during AD 747–753, AD 814–822, AD 846–847, AD 867–874 and AD 914–915 and in the Maghreb AD 867–873, AD 898–915, AD 1104–1147, AD 1280–1340 and AD 1720–1815 had prevalent drought conditions. Intense rain episodes are also reported.

scholarly journals Self-incompatibility in ryegrass VI. Self seed-set and incompatibility genotype in Lolium perenne L

Heredity ◽  
1983 ◽  
Vol 50 (2) ◽  
pp. 169-177 ◽  
Author(s):  
C H Fearon ◽  
M D Hayward ◽  
M J Lawrence
Keyword(s):  
Lolium Perenne ◽  
Seed Set ◽  
Self Incompatibility ◽  
Lolium Perenne L

Onset and duration of stigma receptivity in Kunzea pomifera (Myrtaceae)

2006 ◽  
Vol 54 (6) ◽  
pp. 559 ◽  
Author(s):  
T. Page ◽  
G. M. Moore ◽  
J. Will ◽  
G. M. Halloran
Keyword(s):  
Pollen Tube ◽  
Reproductive Biology ◽  
Peroxidase Activity ◽  
Pollen Tube Growth ◽  
Seed Set ◽  
Stigma Receptivity ◽  
Controlled Pollination ◽  
Germinated Pollen ◽  
New Crop ◽  
Days After Anthesis

The onset and duration of stigma receptivity in K. pomifera was evaluated by observing stigma peroxidase activity, pollen-tube growth and seed set, following controlled pollination of flowers of different ages. Peroxidase activity was negligible from 1 day before to 4 days after anthesis, increasing to a peak of 65% at Day 13. The percentage of pistils bearing germinated pollen and ovaries exhibiting pollen-tube entry increased when pollen was applied to the stigma from the day before anthesis, to a maximum at Days 6 and 7 after anthesis, respectively, followed by a decline by Day 9. Under greenhouse conditions the optimum pollination period, measured as the level of set seed after pollination, ranged from 2 to 11 days after anthesis. The knowledge of this aspect of the species reproductive biology is of considerable value in controlled pollinations for its improvement as a new crop.

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