Breeding systems and related floral traits in several Erysimum (Cruciferae)

1991 ◽  
Vol 69 (11) ◽  
pp. 2515-2521 ◽  
Author(s):  
Gonzalo Nieto Feliner

The breeding system of 13 populations belonging to eight species of Erysimum (Cruciferae) was studied and its relation with the life-span of the plants is discussed. To assess the breeding system of each population, greenhouse tests for apomixis, self-compatibility, and self-pollination were carried out, morphological characters like petal size and anther length were measured and pollen to ovule ratios were computed. The evidence gathered supports the selfing behavior of the three annuals, E. cheiranthoides L., E. incanum G. Kunze, and E. repandum L., and the outcrossing behavior of the perennials E. linifolium (Pers.) Gay, E. asperum (Nutt.) DC, and E. menziesii (Hook.) Wettst. Among those two groups, E. inconspicuum (S. Wats.) MacMillan and E. suffruticosum Sprengel apparently occupy an intermediate position, although the former tends more towards autogamy, whereas the latter tends towards allogamy. The importance of the breeding system data in the systematics of this genus, particularly, in studying the apparent links between the Mediterranean annuals and the temperate E. hieracifolium L. group is briefly discussed. Key words: Erysimum, breeding systems, pollen to ovule ratio, life-span.

1997 ◽  
Vol 75 (5) ◽  
pp. 736-743 ◽  
Author(s):  
Nathalie Escaravage ◽  
André Pornon ◽  
Bernard Doche ◽  
Irene Till-Bottraud

The breeding system of the alpine shrub Rhododendron ferrugineum was studied at two sites of a population (site L and site H) in the French Alps. The aims were to estimate the degree of selling and (or) outcrossing and to determine if floral traits (including floral morphology, pollen to ovule ratio, stigma receptivity) may be related to the breeding system of the shrub. First, floral traits (corolla length and anther, and style heights) were measured, the number of pollen tetrads and ovules were counted, and the date of stigma receptivity and anther dehiscence were recorded. Second, five pollinations treatments (unmanipulated flowers, natural selfing, hand selfing, natural outcrossing, and hand outcrossing) were performed on 35 randomly chosen individuals in each site, and after each treatment the number of seeds per fruit was recorded. The results demonstrate that Rhododendron ferrugineum is self-compatible (self-compatibility index = 0.95 and 0.97; auto-fertility index = 0.92 and 0.98; selfing rate = 0.24 and 0.11 at sites L and H, respectively). Indices values are not significantly different between the two sites and facultatively xenogamous (pollen to ovule ratio = 669.5 ± 280.5 and 845.2 ± 246.9 at sites L and H, respectively). Key words: breeding system, Rhododendron ferrugineum, floral morphology, phenology, P:O ratio.


Insects ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 52 ◽  
Author(s):  
Edward Vargo

Termites are social insects that live in colonies headed by reproductive castes. The breeding system is defined by the number of reproductive individuals in a colony and the castes to which they belong. There is tremendous variation in the breeding system of termites both within and among species. The current state of our understanding of termite breeding systems is reviewed. Most termite colonies are founded by a primary (alate-derived) king and queen who mate and produce the other colony members. In some species, colonies continue throughout their life span as simple families headed by the original king and queen. In others, the primary king and queen are replaced by numerous neotenic (nymph- or worker-derived) reproductives, or less commonly primary reproductives, that are descendants of the original founding pair leading to inbreeding in the colony. In still others, colonies can have multiple unrelated reproductives due to either founding the colonies as groups or through colony fusion. More recently, parthenogenetic reproduction has shown to be important in some termite species and may be widespread. A major challenge in termite biology is to understand the ecological and evolutionary factors driving the variation in termite breeding systems.


2010 ◽  
Vol 58 (2) ◽  
pp. 115 ◽  
Author(s):  
Nan Jiang ◽  
Wen-Bin Yu ◽  
Hong-Zhe Li ◽  
Kai-Yun Guan

Flowers of Clematis display showy corollas and diversified shapes. This diversity motivates study of adaptive evolution of flower–pollinator interactions and the functional association between floral traits and plant mating strategies. An integrative study was undertaken, which focused on pollination and reproductive biology of three species representing all three floral types of Clematis. Floral traits were measured, and pollinator assemblages were observed in the field. Bagging, hand-pollination and removal treatments were used to examine breeding systems. The inbreeding depression and pollen limitation were estimated by fruit-set and seed production obtained from pollination treatments. Their floral traits are distinctly different, but are highly associated with pollination syndrome and breeding system. Among them, Clematis akebioides and C. rehderiana may be facultative autogamy (the former was delayed selfing, and the later competing selfing), and C. chrysocoma may be nearly obligate outcrossing. These conclusions are reflected in their stamen-pistil ratios. The levels of inbreeding depression are negatively associated with autonomous self-pollination. Evolution of self-pollination in C. akebioides and C. rehderiana, and pollen limitation in reproduction of the three Clematis species are discussed. This present study, integrating with previous results, will help us to comprehensively recognise and understand the pollination system and reproductive characteristics of Clematis.


Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 895
Author(s):  
Samira El Hanafi ◽  
Souad Cherkaoui ◽  
Zakaria Kehel ◽  
Ayed Al-Abdallat ◽  
Wuletaw Tadesse

Hybrid wheat breeding is one of the most promising technologies for further sustainable yield increases. However, the cleistogamous nature of wheat displays a major bottleneck for a successful hybrid breeding program. Thus, an optimized breeding strategy by developing appropriate parental lines with favorable floral trait combinations is the best way to enhance the outcrossing ability. This study, therefore, aimed to dissect the genetic basis of various floral traits using genome-wide association study (GWAS) and to assess the potential of genome-wide prediction (GP) for anther extrusion (AE), visual anther extrusion (VAE), pollen mass (PM), pollen shedding (PSH), pollen viability (PV), anther length (AL), openness of the flower (OPF), duration of floret opening (DFO) and stigma length. To this end, we employed 196 ICARDA spring bread wheat lines evaluated for three years and genotyped with 10,477 polymorphic SNP. In total, 70 significant markers were identified associated to the various assessed traits at FDR ≤ 0.05 contributing a minor to large proportion of the phenotypic variance (8–26.9%), affecting the traits either positively or negatively. GWAS revealed multi-marker-based associations among AE, VAE, PM, OPF and DFO, most likely linked markers, suggesting a potential genomic region controlling the genetic association of these complex traits. Of these markers, Kukri_rep_c103359_233 and wsnp_Ex_rep_c107911_91350930 deserve particular attention. The consistently significant markers with large effect could be useful for marker-assisted selection. Genomic selection revealed medium to high prediction accuracy ranging between 52% and 92% for the assessed traits with the least and maximum value observed for stigma length and visual anther extrusion, respectively. This indicates the feasibility to implement genomic selection to predict the performance of hybrid floral traits with high reliability.


Phytotaxa ◽  
2017 ◽  
Vol 318 (1) ◽  
pp. 1 ◽  
Author(s):  
ELTON M. C. LEME ◽  
SASCHA HELLER ◽  
GEORG ZIZKA ◽  
HEIDEMARIE HALBRITTER

The authors provide a new circumscription for genera of the “Cryptanthoid complex” of Bromeliaceae subfam. Bromelioideae, originally composed of Cryptanthus, Lapanthus, Orthophytum, and Sincoraea, on the basis of new or re-evaluated ecological, geographical and morphological evidence, as well as molecular phylogenies. A new generic status is proposed for Cryptanthus subg. Hoplocryptanthus and two new genera, Forzzaea, and Rokautskyia, as well as four new subgenera in Orthophytum (Capixabanthus, Clavanthus, Krenakanthus, and Orthocryptanthus) are described to render taxonomic units monophyletic. The recognized taxa are well circumscribed by the combination of geographical range, ecology and morphological characters (sex distribution, leaf succulence, sepal and petal size and connation, petal appendages, pollen and stigma morphology, fruit size, calyx persistency, seed size and number per fruit). Field collected living specimens of 78 of the 81 species of Cryptanthus s.l., all species of Lapanthus, 58 of the 59 species of Orthophytum, and all species of Sincoraea were analysed in habitat and/or in cultivation, allowing the documentation and illustration of new and underutilized characters. The molecular analysis incorporated 91 accessions representing 33 species of Cryptanthus, all species (3) of Lapanthus, 42 species of Orthophytum, and 9 species of Sincoraea, including the type species for the first three genera and four outgroup taxa. The results suggest, that some morphological characters generally considered homoplasious for Bromelioideae, for the “Cryptanthoid complex”, are not homoplasious at least within the obtained, biogeographycally well delimited clades and their taxonomical utility is redeemed.


2019 ◽  
Vol 192 (4) ◽  
pp. 840-854
Author(s):  
Aline C Gomes ◽  
Bruno H S Ferreira ◽  
Camila S Souza ◽  
Luan M M Arakaki ◽  
Camila Aoki ◽  
...  

Abstract Some epiphytes are adapted to extreme environments with the ability to survive drought as a result of their morphological (xeromorphism), anatomical (foliar trichomes or scales) and physiological features. In contrast to vegetative features, they may have diverse sexual reproductive strategies. Here we compared the flowering morphology, floral biology, breeding system and pollinators of Tillandsia duratii, T. loliacea and T. recurvifolia (Bromeliaceae) adapted to an extreme environment, the Brazilian Chaco. Tillandsia duratii and T. recurvifolia flower for 5–6 months, whereas T. loliaceae flowers for 11 months, mainly in the dry season, with low to high flowering overlap between them. Although these species generally show similar flowering morphology, they differ in size, colour, odour and/or floral functionality, suggesting non-sharing of pollinators among them. Bimodal pollination occurs in T. duratii (bees, moths other than hawkmoths) and T. recurvifolia (butterflies, hummingbirds); in T. loliacea, we recorded no floral visitors. Tillandsia recurvifolia is self-incompatible, has flowers which approach herkogamy and protandry, and depends on pollen vectors for fruit set. The other two species show reverse herkogamy, autonomous self-pollination and self-compatibility (mixed breeding system); therefore, pollinators are not required. The disparity in reproductive strategies among the three species suggests the possibility of selection for diverse modes of reproduction.


2014 ◽  
Vol 43 (1) ◽  
pp. 1-8
Author(s):  
MJ Hasan ◽  
Umma Kulsum ◽  
MH Rahman ◽  
A Akter ◽  
AKM Shamsuddin

Significant variations were obtained among the component lines for most of the floral traits. BRRI9A exhibited superiority for angle of open florets, stigma length and breadth, anther breadth, filament length, style length and panicle exertion rate while its corresponding maintainer lines BRRI9B showed superiority for duration of open florets, stigma length and breadth, anther breadth and filament length. This indicated BRRI9A and its corresponding maintainer line BRRI9B possessed very good floral traits that influence out crossing. Among the restorer lines BR168R showed superiority for duration of open florets, angle of open florets, duration of bloomed florets/panicle, stigma length, anther length and number of pollen/microscopic focus. This suggested BR168R could be used as promising restorer line with BRRI9A for hybrid seed production in local condition.DOI: http://dx.doi.org/10.3329/bjb.v43i1.19739 Bangladesh J. Bot. 43(1): 1-8, 2014 (June)


1992 ◽  
Vol 40 (1) ◽  
pp. 13 ◽  
Author(s):  
WG Breed ◽  
M Adams

This study was carried out as part of a broader investigation into the factors that determine interspecific variation in testis size amongst conilurine rodents. The hypothesis proposed is that the huge differences in absolute and relative testis size between the spinifex hopping mouse (Notomys alexis) and the plains rat (Pseudomys australis) relate to differences in breeding system. One aspect of a species' breeding system, the capacity for multiple paternity, was assessed under laboratory conditions for each species. Allozyme markers were used to set up appropriate trios consisting of one female cohabiting with two mates of different genotypes and to assess the paternity of the resultant pups that were born. Multiple paternity within a single litter was not recorded for hopping mice but was observed occasionally in plains rats, a result consistent with the hypothesis under test.


1959 ◽  
Vol 57 (4) ◽  
pp. 386-402 ◽  
Author(s):  
A. A. Tuffery

Two units, within a mouse-breeding colony, with different breeding systems, have been compared from the point of view of general healthiness of the breeding stock. In one unit the monogamous-pair system, involving post-partum oestrus mating, was employed and in the other the harem system, with isolation of the pregnant females for each litter-down until after the post-partum oestrus. The two units were housed separately and had different staffs. The monogamous-pair unit was accommodated in four small rooms not directly connected; the harem unit in two larger connecting rooms. The methods of cageing, bedding, feeding, watering, care, culling and subsequent procedures were identical for both units and the same system of recording individual detailed information relating to health and breeding was followed for the two units. The size of the two populations studied was 1198 and 1024, respectively, the larger number belonging to the harem unit in which the mice were retained for a significantly longer period. These mice were moved more frequently and handled much more often.Apart from a small outbreak of Tyzzer's disease (in the harem-bred unit) and sporadic cases in both units spread over the whole period of the survey—some 3–4 years—the general health of the two units was good. There were no cases of salmonella infection, mousepox, pasteurellosis or other serious infections. Throughout the period both units maintained a high standard of productivity and there was no evidence that the mating of the monogamous pairs at the post-partum oestrus led to any weakness or ill health. As would be expected, however, the losses from death and culling were greater among the females in both units.The health record of the monogamous-pair bred unit was consistently higher than that of the harem-bred unit. There were more cases of Tyzzer's disease in the harem-bred mice and more evidence generally of ill health in this unit. Infertility was three times greater with the harem-bred mice as compared with those in the monogamous-pair unit.Details of the two systems are discussed and although the records maintained for the two may not be strictly comparable it is concluded that, under the conditions obtaining, the monogamous-pair breeding system yielded a healthier colony of mice than the harem breeding system.I should like to thank Dr J. S. Patterson and Mr R. Cook for placing many of their records at my disposal, Mr S. Peto and his staff for carrying out much of the tedious compilation of data, and Dr D. W. Henderson, F.R.S., for affording me facilities for this work. To these I am especially grateful for their interest, advice and assistance.


1990 ◽  
Vol 38 (2) ◽  
pp. 217 ◽  
Author(s):  
AJ Willis ◽  
JE Ash

The breeding systems of Stylidiurn grarninifolium and S. producturn (= S. grarninifoliurn var. caulescens) were studied by observing the phenology of individual flowers and inflorescences, and relating the data to a series of pollination experiments within and between the species. Inter-specific pollinations yielded similar levels of seed-set to crosses within the species indicating a close relationship between the taxa. Self-pollination of either species is uncommon; however, when it occurs, the majority of selfed ovules are aborted post-zygotically, probably by a system of recessive lethals, as there is no indication of an incompatibility system. It is concluded that the breeding systems of S. grarninifoliurn and S. productum, two of the few eastern Australian species, are similar to those of many Stylidiurn species from the south-west, casting doubt upon hypotheses that the breeding system has led to high rates of speciation in the south-west.


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