The breeding system of Lycium cestroides : a Solanaceae with ovarian self-incompatibility

2001 ◽  
Vol 13 (5) ◽  
pp. 273-277 ◽  
Author(s):  
R. Aguilar ◽  
Gabriel Bernardello
Keyword(s):  
Breeding System ◽  
Self Incompatibility

scholarly journals Interaction Between Ploidy, Breeding System, and Lineage Diversification

2019 ◽  
Author(s):  
Rosana Zenil-Ferguson ◽  
J. Gordon Burleigh ◽  
William A. Freyman ◽  
Boris Igić ◽  
Itay Mayrose ◽  
...  
Keyword(s):  
Breeding System ◽  
Whole Genome Duplication ◽  
Genome Duplication ◽  
Whole Genome ◽  
Self Incompatibility ◽  
Evolutionary Pathway ◽  
Diversification Rates ◽  
Extinction Rates ◽  
Biological Hierarchy ◽  
Lineage Diversification

AbstractIf particular traits consistently affect rates of speciation and extinction, broad macroevolutionary patterns can be understood as consequences of selection at high levels of the biological hierarchy. Identifying traits associated with diversification rate differences is complicated by the wide variety of characters under consideration and the statistical challenges of testing for associations from comparative phylogenetic data. Ploidy (diploid vs. polyploid states) and breeding system (self-incompatible vs. self-compatible states) have been repeatedly suggested as possible drivers of differential diversification. We investigate the connections of these traits, including their interaction, to speciation and extinction rates in Solanaceae. We show that the effect of ploidy on diversification can be largely explained by its correlation with breeding system and that additional unknown factors, alongside breeding system, influence diversification rates. These results are largely robust to allowing for diploidization. Finally, we find that the most common evolutionary pathway to polyploidy in Solanaceae occurs via direct breakdown of self-incompatibility by whole genome duplication, rather than indirectly via breakdown followed by polyploidization.

Breeding System, Karyotype and Variation Within and Between Populations of Rutidosis leptorrhynchoides F Muell (Asteraceae, Inuleae)

1991 ◽  
Vol 39 (1) ◽  
pp. 85 ◽  
Author(s):  
P Leeton ◽  
YJ Fripp
Keyword(s):  
Chromosome Number ◽  
Breeding System ◽  
Geographic Distance ◽  
Endangered Plant ◽  
Allozyme Analysis ◽  
Self Incompatibility ◽  
Eastern Australia ◽  
Incompatibility System ◽  
Leaf Dimensions ◽  
Allozyme Loci

The endangered plant species, Rutidosis leptorrhynchoides (button wrinklewort), is now known from only a few populations in each of two regions separated by approximately 500 km in south-eastern Australia. Plants were examined from several populations from each region. No differences in chromosome number or morphology were observed among plants or populations. All counts were diploid, 2n = 26. Viable progeny were obtained following self-pollination and allozyme analysis indicated that these progeny were the result of selfing and not agamospermy. This species is not an obligate outcrosser and does not have a classical pre-zygotic self-incompatibility system. However, outcross pollen may have an advantage over self pollen and this species may thus be preferentially outcrossing. The pollen: ovule ratios (mean 3186 ± 48.5) were consistent with this hypothesis. Allele frequencies at allozyme loci diferred little between populations, with an estimated 97% of the variation within populations. There was no correlation between genetic distance and geographic distance. In contrast, for the leaf dimensions of plants germinated and raised together in a glasshouse there were differences between plants from the two regions. It is recommended that populations from both regions should be conserved.

Floral biology and late-acting self-incompatibility in Jacaranda racemosa (Bignoniaceae)

2006 ◽  
Vol 54 (3) ◽  
pp. 315 ◽  
Author(s):  
Nelson S. Bittencourt ◽  
João Semir
Keyword(s):  
Breeding System ◽  
Histological Analysis ◽  
Floral Biology ◽  
Self Incompatibility ◽  
Flower Visitation ◽  
Hand Pollination ◽  
Natural Pollination ◽  
Ovule Penetration ◽  
Incompatibility Barrier

Breeding-system studies have been conducted with 38 of the approximately800 species of Bignoniaceae, and self-incompatibility was found in 31 of these. In species for which the site of self-incompatibility barrier was studied, self-pollinated flowers consistently failed to develop into fruits, even though pollen tubes grew down to the ovary and penetrated most of the ovules. In this study, we have investigated the floral biology and the breeding system in Jacaranda racemosa Chamisso, with hand-pollination experiments and the histology of post-pollination events. Flower anthesis lasted 1–3 days, and although the frequency of flower visitation was extremely low, natural pollination seemed to be effected mainly by medium-sized bees. Because the conspicuous staminodium favours eventual pollination by small bees, a possible role of the staminodium in the increase of potential pollinators is suggested. Hand-pollinations indicated that J. racemosa is a self-sterile species. Histological analysis of post-pollination events indicated the occurrence of a kind of late-acting self-incompatibility in which the processes of ovule penetration, fertilisation and endosperm initiation were slower in selfed than in crossed pistils. Until the time of self-pollinated pistil abscission, no signs of endosperm malfunction or proembryo development were observed in selfed pistils. Therefore, inbreeding depression is an unlikely explanation for self-sterility in J. racemosa.

scholarly journals Genetic interaction between two unlinked loci underlies the loss of self-incompatibility in Arabidopsis lyrata

2019 ◽  
Author(s):  
Yan Li ◽  
Mark van Kleunen ◽  
Marc Stift
Keyword(s):  
Breeding System ◽  
Genetic Basis ◽  
Genetic Model ◽  
Genetic Interaction ◽  
Current Knowledge ◽  
Breeding Systems ◽  
Self Incompatibility ◽  
Arabidopsis Lyrata ◽  
Loss Of Self ◽  
Selfing Species

AbstractAs the first step towards the evolution of selfing from obligate outcrossing, identifying the key mutations underlying the loss of self-incompatibility is of particular interest. However, our current knowledge is primarily based on sequence-based comparisons between selfing species and their self-incompatible relatives, which makes it hard to distinguish causal from secondary mutations. To by-pass this problem, we inferred the genetic basis of the loss of self-incompatibility by intercrossing plants from twelve geographically interspersed outcrossing and selfing populations of North-American Arabidopsis lyrata and determining the breeding system of 1,580 progeny. Self-incompatibility was not restored after crosses between different self-compatible populations. Equal frequencies of self-compatible and self-incompatible progeny emerged from crosses between parents with different breeding systems. We propose a two-locus genetic model for the loss of self-incompatibility in which specific S-locus haplotypes (S1 and S19) are associated with loss of self-incompatibility through their interaction with an unlinked modifier.

The Cytology, Breeding System and Flowering Behaviour of Panicum coloratum

1974 ◽  
Vol 22 (1) ◽  
pp. 57 ◽  
Author(s):  
AJ Pritchard ◽  
IHD Lacy
Keyword(s):  
Breeding System ◽  
Variable Number ◽  
The Other ◽  
Self Incompatibility ◽  
Open Pollination ◽  
Panicum Coloratum ◽  
Flowering Behaviour ◽  
Close Relationship ◽  
Generative Cells ◽  
Accessory Chromosomes

A collection of 47 accessions of Panicum coloratum was classified into five morphologically distinct types. One of these was uniformly hexaploid (2n = 54) and another was diploid (2n = 18). The other three were mainly tetraploid (2n = 36) but some pentaploid (2n = 45) plants and one septaploid (2n = 63) plant were found. Meiosis was regular in all euploid plants but nine univalents were usually present in the pentaploid plants. A variable number of accessory chromosomes were found in somatic and generative cells in some plants of two of the types, and hybridization studies indicated a close relationship between these. It is suggested that both tetraploids and hexaploids are allopolyploids and that the hexaploid has two genomes in common with the tetraploids. All accessions set adequate seed following open pollination, but shed seed readily at maturity. There was variation in the degree of self-incompatibility both within and between types. In some accessions up to 33% of the florets were capable of setting seed when self-pollinated. P. coloratum grew best and flowered earliest in long days (I6 hr) and a day temperature of 27-30°C.

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.

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