Recent selection for self-compatibility in a population of Leavenworthia alabamica

Evolution ◽  
2016 ◽  
Vol 70 (6) ◽  
pp. 1212-1224 ◽  
Author(s):  
Adam C. Herman ◽  
Daniel J. Schoen
Keyword(s):  
Self Compatibility ◽  
Selection For ◽  
Recent Selection

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.

Adaptive response of extreme epiphyte Tillandsia species (Bromeliaceae) is demonstrated by different sexual reproduction strategies in the Brazilian Chaco

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 ◽  
...  
Keyword(s):  
Breeding System ◽  
Reproductive Strategies ◽  
Extreme Environments ◽  
Extreme Environment ◽  
Floral Biology ◽  
Reproduction Strategies ◽  
Pollen Vectors ◽  
Self Compatibility ◽  
Floral Visitors ◽  
Selection For

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.

Genetic modifications of dimorphic incompatibility in the Turnera ulmifolia L. complex (Turneraceae)

1986 ◽  
Vol 28 (5) ◽  
pp. 796-807 ◽  
Author(s):  
J. S. Shore ◽  
S. C. H. Barrett
Keyword(s):  
Genetic Control ◽  
Moderate Degree ◽  
Self Incompatibility ◽  
Tetraploid Population ◽  
Polygenic Control ◽  
Genetic Modifications ◽  
Self Compatibility ◽  
Turnera Ulmifolia ◽  
Low Levels ◽  
Selection For

Diploid and tetraploid populations of Turnera ulmifolia are distylous and exhibit a strong self-incompatibility system. Distyly is governed by a single locus with two alleles. Several self-compatible variants were, however, obtained and the nature and genetic control of self-compatibility was assessed using controlled crosses. The study documented the occurrence of self-compatible variants in four contrasting situations. These included the following. (i) Self-compatibility in a diploid short-styled variant. The gene(s) governing self-compatibility interact with the distyly locus and are expressed only in short-styled plants. When tetraploids carrying the genes were synthesized, self-incompatibility reappeared. (ii) Self-compatibility occurred in a cross between geographically separate diploid populations. Self-compatibility appeared sporadically in the F1. Crosses revealed that self-compatibility is likely under polygenic control. (iii) Low levels of self-compatibility occurred in a tetraploid population. Crosses revealed that self-compatibility was under polygenic control. A small response to selection for increased self-compatibility was observed, (iv) Hexaploids were synthesized from crosses between distylous diploids and tetraploids. All hexaploids obtained were long- or short-styled indicating that hexaploidy per se does not cause homostyly. A single long-styled plant showed aberrant pollen behaviour, resulting in a moderate degree of self-compatibility. All of the variants studied exhibited either aberrant pollen or stylar incompatibility responses. In no instance was the genetic control of self-compatibility solely the result of segregation at the distyly locus.Key words: Turnera, dimorphic incompatibility, polyploidy, self-compatibility, distyly.

On the Expenses and Selection as affecting the Pure Premium Method of Valuation

1878 ◽  
Vol 21 (3) ◽  
pp. 192-203 ◽  
Author(s):  
James Sorley
Keyword(s):  
Practical Interest ◽  
The Other ◽  
Pure Premium ◽  
New Business ◽  
Selection For ◽  
The One ◽  
Selection Of ◽  
Recent Selection

Although much has been written in recent years on the comparative merits of different methods of valuation, I am not aware that any attempt has yet been made to ascertain the ultimate bearing on the Pure Premium Method, of the facts that have been recently brought forward as to the pressure of the expenses and the effects of selection in an assurance company. Speaking generally, it will, I think, be found that proposals to diminish the pure premium reserve on account of the necessarily heavy expenses of new business, have been made without reference to the mortality profit that may be expected to arise from the recent selection of the lives, and vice versa. This being the case, it occurred to me that it might be of considerable practical interest to make an investigation in which effect would be given to the influence both of expenses and of selection, for it would enable us to estimate how far the one neutralized the other. In order to render the inquiry more clear, however, it will be well to begin by considering each separately.

scholarly journals Stronger signal of recent selection for lactase persistence in Maasai than in Europeans

2012 ◽  
Vol 21 (5) ◽  
pp. 550-553 ◽  
Author(s):  
Carina M Schlebusch ◽  
Per Sjödin ◽  
Pontus Skoglund ◽  
Mattias Jakobsson
Keyword(s):  
Lactase Persistence ◽  
Selection For ◽  
Recent Selection

scholarly journals Comparison of Genetic Merit for Weight and Meat Traits between the Polled and Horned Cattle in Multiple Beef Breeds

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 870
Author(s):  
Imtiaz A. S. Randhawa ◽  
Michael R. McGowan ◽  
Laercio R. Porto-Neto ◽  
Ben J. Hayes ◽  
Russell E. Lyons
Keyword(s):  
Birth Weight ◽  
Live Weight ◽  
Practical Solution ◽  
Genetic Merit ◽  
Production Parameters ◽  
Genetic Potential ◽  
Lower Productivity ◽  
Selection For ◽  
Estimated Breeding Values ◽  
Recent Selection

Breeding for polled animals is deemed the most practical solution to eradicate horns naturally and circumvent management costs and risks on health and welfare. However, there has been a historical reluctance by some farmers to select polled animals due to perceived lower productivity of their calves. This study has compared estimated breeding values (EBVs) between horned and polled animals (N = 2,466,785) for 12 production and carcass traits to assess historical (before 2000) and recent (2000–2018) genetic implications of poll breeding. Older generations of the polled animals in most breeds had significantly lower (Bonferroni-corrected p = 0.05) genetic merits for live (birth to maturity) and carcass weights, milk, meat quality, and fat content traits. Substantial gains of genetic potential were achieved during 2000 to 2018 in each breed, such that polled animals have significantly improved for the majority of traits studied. Generally, polled cohorts showed advantageous EBVs for live and carcass weights irrespective of the lower birth weights in some breeds. While Polled Brahman showed inferior production parameters, the poll genetics’ effect size (d) and correlation (r) were very small on recent birth weight (d = −0.30, r = −0.08), 200 days (−0.19, −0.05), 400 days (−0.06, −0.02), 600 days (−0.05, −0.01), mature cow live weight (−0.08, −0.02), and carcass weight (−0.19, −0.05). In conclusion, although there is some evidence that historical selection for polled breeding animals may have reduced productivity, there is strong evidence that more recent selection for polled genotypes in the breeds studied has not resulted in any adverse effects on genetic merit.

scholarly journals The Australian DRG classification:are we ready for structural changes?

2001 ◽  
Vol 24 (3) ◽  
pp. 16
Author(s):  
Don Hindle
Keyword(s):  
Health Care ◽  
Structural Changes ◽  
Health Care Systems ◽  
Empirical Studies ◽  
The World ◽  
Care Systems ◽  
Selection For ◽  
Recent Selection

The Australian DRG variant compares favourably with other variants in use around the world. This view is supported by a variety of empirical studies and by experiences of its adoption by several health care systems. An example is its recent selection for use in Germany (Hindle & Lenz, 2000).

Cliff-edged fitness functions and the persistence of schizophrenia

2004 ◽  
Vol 27 (6) ◽  
pp. 862-863 ◽  
Author(s):  
Randolph M. Nesse
Keyword(s):  
Social Cognition ◽  
Fitness Function ◽  
Specific Mechanism ◽  
Fitness Functions ◽  
The Mean ◽  
Selection For ◽  
Recent Selection

Strong recent selection for social cognition may well explain the persistence of genes that predispose to schizophrenia. The specific mechanism responsible may be a skewed fitness function in which selection pushes the mean for advantageous mental traits perilously close to a “fitness cliff” where the system fails catastrophically in some individuals.

SELF-COMPATIBILITY OF CARAGANA ARBORESCENS LAM.

1955 ◽  
Vol 33 (2) ◽  
pp. 149-155 ◽  
Author(s):  
W. H. Cram
Keyword(s):  
Frequency Distribution ◽  
Self Incompatibility ◽  
Pollen Abortion ◽  
Plant Vigor ◽  
Caragana Arborescens ◽  
Self Compatibility ◽  
Selection For ◽  
A Minor ◽  
Angular Transformation

Self-compatibility (% of 'tripped' flowers setting pods) for 218 selections of Caragana arborescens varied continuously from 0.0 to 99.5%. The frequency distribution of the compatibility data in terms of percentage was positively skewed by an excess of low self-compatibility plants and had a mean of 36.9%. However, angular transformation of the data resulted in a distribution which approached normality. Pollen abortion, which ranged from 0 to 24%, had little if any influence upon self-compatibility. Selection for high plant vigor was accompanied by a minor reduction in compatibility. Self-incompatibility of three trees could be explained by the action of several compatibility [Formula: see text] factors.

scholarly journals Unravelling selection signatures in a single dog breed suggests recent selection for morphological and behavioral traits

2020 ◽  
Vol 1 (1) ◽  
pp. e10024 ◽  
Author(s):  
Juliane Friedrich ◽  
Andrea Talenti ◽  
Per Arvelius ◽  
Erling Strandberg ◽  
Marie J. Haskell ◽  
...  
Keyword(s):  
Selection Signatures ◽  
Behavioral Traits ◽  
Dog Breed ◽  
Selection For ◽  
Recent Selection
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