scholarly journals Inbreeding Depression of Progenies of Castor Bean, From of the Variety FCA-PB, Results of Three Types of Pollinations

2019 ◽  
Vol 11 (16) ◽  
pp. 68
Author(s):  
Jackson da Silva ◽  
Andréia Rodrigues Ramos ◽  
Deoclecio Jardim Amorim ◽  
Maurício Dutra Zanotto ◽  
Maria Márcia Pereira Sartori
Keyword(s):  
Inbreeding Depression ◽  
Castor Bean ◽  
Inbreeding Coefficient ◽  
Genetic Aspect ◽  
Self Pollination ◽  
Lower Productivity ◽  
Grain Productivity ◽  
Wide Range ◽  
Productivity Variable ◽  
Coefficient Of Inbreeding

Oil of castor bean despite its wide range of use, still present a relevant deficit in the Brazilian market. This deficit could be softened or extinguished with increased productivity, in which the genetic aspect has a great contribution. The most productive genotypes are the hybrid varieties, however for obtaining the hybrids pure lineages are required which have appropriate agronomic characteristics and that express the minimum of inbreeding depression. Thus, the objective of this research was to evaluate the inbreeding depression of castor bean progenies, from the cultivar FCA-PB, resulting from three types of pollination. The experiments were implanted in design in randomized blocks, in the 30 × 3 factorial scheme, being 30 progenies and 3 types of pollination (free, cross and self-pollination), in 2 environments (São Manuel and Araçatuba) and in 2 crops (2004/2005 and 2005/2006), with three replications. Inbreeding depression was estimated under the grain productivity variable. It was observed that cross-pollination presented grain productivity close to 2500 kg ha-1, in which the lowest coefficient of inbreeding was determined, zero (0). Opposed It self-pollination, in which resulted in lower productivity, around 2000 kg ha-1, and the highest inbreeding coefficient being of 0.77. The reflection of the coefficient of inbreeding on productivity presents inversely proportional behavior, ie, the measure that increases the coefficient of inbreeding decreases the grain yield.

scholarly journals Depression by inbreeding after four sucessive self-pollination squash generations

2004 ◽  
Vol 61 (2) ◽  
pp. 224-227 ◽  
Author(s):  
Antonio Ismael Inácio Cardoso
Keyword(s):  
Regression Analysis ◽  
Seed Production ◽  
Inbreeding Depression ◽  
Seed Quality ◽  
Inbreeding Coefficient ◽  
Cucurbita Moschata ◽  
F1 Hybrid ◽  
Self Pollination ◽  
Parental Lines ◽  
Level Effect

The strategy for breeding F1 hybrid squash is to develop parental lines through self-pollination. However, it increases plant mean homozygosis, which is not the natural genetic state of a cross-pollinated species, and can cause "inbreeding depression". The objective of this work was to evaluate this depression with sucessive generations of self-pollination (without selection) in Cucurbita moschata, cv. Piramoita. Populations were obtained from lines with one to four generations of self-pollination (obtained by the SSD method), from the original cv. Piramoita (population S0). Randomized blocks were used with five treatments (different generations of self-pollination - S0 to S4), six replicates and five plants per plot. Regression analysis was made by the Wright inbreeding coefficient (F) to measure the homozygosis level effect on vigor loss. There was a linear reduction of mean weight and fruit length, seed production (number and weight) per fruit with the increase of the homozygosis level; however inbreeding did not affect seed quality (weight of 100 seeds and germination).

scholarly journals Effects of inbreeding on number of piglets born total, born alive and weaned in Austrian Large White and Landrace pigs

2009 ◽  
Vol 52 (1) ◽  
pp. 51-64 ◽  
Author(s):  
A. Köck ◽  
B. Fürst-Waltl ◽  
R. Baumung
Keyword(s):  
Inbreeding Depression ◽  
Reproductive Performance ◽  
Regression Models ◽  
Inbreeding Coefficient ◽  
Significant Positive Effect ◽  
Weaned Piglets ◽  
Large White ◽  
Inbreeding Coefficients ◽  
Negative Effect ◽  
Positive Effect

Abstract. In this study records of 58 925 litters of Austrian Large White and 17 846 litters of Austrian Landrace pigs were analysed. Regression models were used to determine the effects of litter, dam and sire inbreeding on total number of born, born alive and weaned piglets in Large White and Landrace. In both populations, litter and dam inbreeding showed a negative effect on all traits. Sire inbreeding had no effect in Large White, whereas a significant positive effect was observed in Landrace. On average, inbred sires with an inbreeding coefficient of 10 % had 0.45 more piglets born total and 0.43 more piglets born alive in comparison to non-inbred sires. In a further analysis the total inbreeding coefficients of the animals were divided into two parts: »new« and »old« inbreeding. »New« inbreeding was defined as the period of the first five generations. It was shown that the observed inbreeding effects were not only caused by recent inbreeding. Reproductive performance was also affected by »old« inbreeding. Finally partial inbreeding coefficients of four important ancestors in each population were calculated to investigate if inbreeding effects are similar among these ancestors. The results revealed a varation of inbreeding effects among the four ancestors. Alleles contibuting to inbreeding depression were descendent from specific ancestors.

23 Sperm quality of Pure Spanish stallions is affected by inbreeding coefficient and age

2020 ◽  
Vol 32 (2) ◽  
pp. 137
Author(s):  
Y. Pirosanto ◽  
M. Valera ◽  
A. Molina ◽  
J. Dorado ◽  
S. Demyda-Peyrás
Keyword(s):  
Sperm Motility ◽  
Inbreeding Depression ◽  
Negative Correlation ◽  
Semen Quality ◽  
Sperm Quality ◽  
Sperm Concentration ◽  
Inbreeding Coefficient ◽  
Semen Parameters ◽  
Computer Assisted

Inbreeding depression, a genetic condition produced by the mating of close-related individuals, has been associated with a reduction of fertility in several species. However, a loss in sperm quality was also associated with age. In horses, the few existing reports have described a tendency of both parameters to produce a negative effect on sperm quality. However, those reports were performed using a subjective evaluation of sperm motility. In the present study, a total of 692 ejaculates from 86 Pure Spanish stallions (PRE), aged between 3 and 22 years, were evaluated using a computer-assisted methodology to determine the effect of inbreeding in four semen parameters: free-gel volume (V), sperm concentration (C, by haemocytometer), and total (TM) and progressive (PM) sperm motility (by Spermvision sperm class analyser; Minitube). The inbreeding coefficient (F) was estimated using 300 000 PRE pedigree records approximately (minimum pedigree depth, eight equivalent complete generations; range, between 1 and 30.1%). Stallion, age, ejaculate, and season of semen collection were the variables included in the statistical model (general linear model), with ejaculate and season being the variables with a major effect (by variance components analysis). Our results showed that sperm concentration (r=−0.18; P<0.0001) and volume (to a lesser extent) were reduced with advancing age, both showing a major decline after 15 years of age. To the contrary, sperm motility was not affected by age of the stallion. We also found a negative correlation between the inbreeding coefficient and ejaculate volume (r=−0.14; P<0.001), with a marked decrease seen when F was between 7 and 20%. Also, a negative correlation was observed in PM (r=−0.08; P<0.05), although to a lower extent. Conversely, C and TM were not affected by inbreeding depression (P>0.05). In conclusion, our results demonstrated that high levels of inbreeding can compromise severely the sperm quality of the PRE stallion, which, subsequently, may have a negative influence on fertility. Ongoing studies using genomic data will help to detect genetic variants associated with stallion semen quality and how it is influenced by inbreeding in specific genomic regions.

Inbreeding and its effects on some economic traits in Raeini cashmere goats

2003 ◽  
Vol 2003 ◽  
pp. 147-147 ◽  
Author(s):  
M. Moradi-Shaharbabak ◽  
A. Mohammadi ◽  
S. R. Miraei-Ashtiani
Keyword(s):  
Body Weight ◽  
Inbreeding Depression ◽  
Fiber Length ◽  
Inbreeding Coefficient ◽  
Base Population ◽  
Economic Traits ◽  
Breeding Center ◽  
Cashmere Goats ◽  
Fleece Weight ◽  
The Impact

The Breeding Center of Raeini (BCR) cashmere goats was established in 1965 in Kerman province, with a base population of 120, 8 and 42 does, bucks, and kids respectively. Some new animals have been introduced to the BCR population in some periods of time, and selected males have been sold out to the local breeders each year. Animals have been selected based on their phenotypic performance for fleece weight (FW) and fleece color (FC-white), and body weight (BW). Mating system has been planned based on non-relative mating, but some relative mating has been occurred. Inbreeding depression is one of the most important empact of having inbreeding in a population (Miglior and Burnside 1995). A decrease of 0.8% in fiber length and 6.3% in longevity per 10% increase of inbreeding coefficient in cashmere goats has been reported (Deb 1998). The objective of this study was to estimate the animals inbreeding coefficient and to explore the impact of inbreeding on some economic traits in Raeini cashmere goats.

scholarly journals The effects of inbreeding on the components of litter size in mice

1967 ◽  
Vol 10 (1) ◽  
pp. 73-80 ◽  
Author(s):  
J. C. McCarthy
Keyword(s):  
Litter Size ◽  
Inbreeding Depression ◽  
First Generation ◽  
Inbreeding Coefficient ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Base Population ◽  
Pregnant Females ◽  
Sib Mating ◽  
Size At Birth

Twenty-four lines were bred from a base population of outbred Q mice by continued full-sib mating. Inbreeding depression in litter size at birth was observed. This decline in litter size was analysed in terms of ovulation rate, the incidence of preimplantation mortality and the incidence of postimplantation mortality. Pregnant females were dissected at 17½ days' gestation and the numbers of corpora lutea, or eggs, and of live and dead embryos were counted. Matings were arranged so that separate estimates of the effects of inbreeding in the mother and in the litter on the components of litter size could be obtained.In the first generation of inbreeding when the inbreeding coefficient of the litter was raised from 0 to 25% decline in litter size was attributable to an increased incidence of preimplantation mortality.In the second and fourth generations decline in litter size was attributable to (1) a reduction in the number of eggs ovulated by the inbred mothers, (2) an increased incidence of preimplantation mortality which resulted from inbreeding in the mother. No evidence of significant effects on mortality of inbreeding in the litter was obtained in the later generation of inbreeding.These findings are discussed in the context of previous work on the effects of inbreeding and crossing on litter size and its components in mice and pigs.

Seed abortion in the bat pollinated Neotropical tree species, Caryocar brasiliense (Caryocaraceae)

Botany ◽  
2009 ◽  
Vol 87 (11) ◽  
pp. 1110-1115 ◽  
Author(s):  
Rosane G. Collevatti ◽  
Raquel Estolano ◽  
Silmara F. Garcia ◽  
John D. Hay
Keyword(s):  
Inbreeding Depression ◽  
Tree Species ◽  
Resource Limitation ◽  
Sibling Rivalry ◽  
Assignment Test ◽  
Seed Abortion ◽  
Neotropical Tree ◽  
Self Pollination ◽  
Caryocar Brasiliense ◽  
Maternal Regulation

In self-compatible plants, the reduction in brood size may be caused either by inbreeding depression, resource limitation, maternal regulation of offspring quality, or by sibling rivalry. We studied seed abortion in Caryocar brasiliense Camb. (Caryocaraceae), a Neotropical tree species, to verify whether seeds sired by self-pollination are aborted. Fruits were sampled from 23 mother trees to estimate seed set and proportion of aborted seeds. Ripened and aborted seeds from 18 mother trees were genotyped using 10 microsatellite loci together with mother trees and all nearby adults (83 adults) to determine the pollen donor by assignment test. From the 541 seeds, 190 were aborted and the mean number of aborted seeds per fruit was 0.627 (SD = 0.807). Proportion of aborted seeds was different among mother trees and among fruits within mother trees. All but three aborted seeds were sired by self-pollination and selfed seeds were aborted in fruits harbouring both selfed and outcrossed seeds. Aborted outcrossed seeds were sired by pollen donors closely related to mother trees. Our results strongly support that seed abortion in C. brasiliense may be the outcome of inbreeding depression and sibling rivalry when selfed and outcross pollinated ovules compete.

scholarly journals Effect of partial selfing and polygenic selection on establishment in a new habitat

2019 ◽  
Author(s):  
Himani Sachdeva
Keyword(s):  
Inbreeding Depression ◽  
Evolutionary Dynamics ◽  
High Rate ◽  
Source Population ◽  
Selfing Rate ◽  
Deleterious Alleles ◽  
Wide Range ◽  
Mate Limitation ◽  
Polygenic Selection

AbstractThis paper analyzes how partial selfing in a large source population influences its ability to colonize a new habitat via the introduction of a few founder individuals. Founders experience inbreeding depression due to partially recessive deleterious alleles as well as maladaptation to the new environment due to selection on a large number of additive loci. I first introduce a simplified version of the Inbreeding History Model (Kelly, 2007) in order to characterize mutation-selection balance in a large, partially selfing source population under selection involving multiple non-identical loci. I then use individual-based simulations to study the eco-evolutionary dynamics of founders establishing in the new habitat under a model of hard selection. The study explores how selfing rate shapes establishment probabilities of founders via effects on both inbreeding depression and adaptability to the new environment, and also distinguishes the effects of selfing on the initial fitness of founders from its effects on the long-term adaptive response of the populations they found. A high rate of (but not complete) selfing is found to aid establishment over a wide range of parameters, even in the absence of mate limitation. The sensitivity of the results to assumptions about the nature of polygenic selection are discussed.

scholarly journals Inbreeding depression and genetic load at partially linked loci in a metapopulation

2010 ◽  
Vol 92 (2) ◽  
pp. 127-140 ◽  
Author(s):  
SHU-RONG ZHOU ◽  
JOHN R. PANNELL
Keyword(s):  
Inbreeding Depression ◽  
Random Mating ◽  
Genetic Load ◽  
Minor Effect ◽  
Deleterious Mutations ◽  
Recombination Rates ◽  
Sexual Systems ◽  
Biological Phenomena ◽  
Population Turnover ◽  
Wide Range

SummaryInbreeding depression has important implications for a wide range of biological phenomena, such as inbreeding avoidance, the evolution and maintenance of sexual systems and extinction rates of small populations. Previous investigations have asked how inbreeding depression evolves in single and subdivided populations through the fixation of deleterious mutations as a result of drift, as well as through the expression of deleterious mutations segregating in a population. These studies have focused on the effects of mutation and selection at single loci, or at unlinked loci. Here, we used simulations to investigate the evolution of genetic load and inbreeding depression due to multiple partially linked loci in metapopulations. Our results indicate that the effect of linkage depends largely on the kinds of deleterious alleles involved. For weakly deleterious and partially recessive mutations, the speed of mutation accumulation at segregating loci in a random-mating subdivided population of a given structure tends to be retarded by increased recombination between adjacent loci – although the highest numbers of fixation of slightly recessive mutant alleles were for low but finite recombination rates. Although linkage had a relatively minor effect on the evolution of metapopulations unless very low values of recombination were assumed, close linkage between adjacent loci tended to enhance population structure and population turnover. Finally, within-deme inbreeding depression, between-deme inbreeding depression and heterosis generally increased with decreased recombination rates. Moreover, increased selfing reduced the effective amount of recombination, and hence the effects of tight linkage on metapopulation genetic structure were decreased with increasing selfing. In contrast, linkage had little effect on the fate of lethal and highly recessive alleles. We compare our simulation results with predictions made by models that ignore the complexities of recombination.

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