A model for the maintenance of genetic variability and its utilization in genetic improvement of oyster populations

Aquaculture ◽  
1978 ◽  
Vol 15 (3) ◽  
pp. 289-295 ◽  
Author(s):  
S.M. Singh
Keyword(s):  
Genetic Variability ◽  
Genetic Improvement

scholarly journals Genetic improvement and population structure of the Nelore breed in Northern Brazil

2010 ◽  
Vol 45 (10) ◽  
pp. 1109-1116 ◽  
Author(s):  
Carlos Henrique Mendes Malhado ◽  
Paulo Luiz Souza Carneiro ◽  
Ana Claudia Mendes Malhado ◽  
Raimundo Martins Filho ◽  
Riccardo Bozzi ◽  
...  
Keyword(s):  
Population Structure ◽  
Genetic Variability ◽  
Genetic Improvement ◽  
Selective Breeding ◽  
Growth Traits ◽  
Management Strategies ◽  
Pedigree Information ◽  
Effective Number ◽  
Northern Brazil ◽  
Nelore Cattle

The objective of this work was to evaluate the population structure and the genetic and phenotypic progress of Nelore cattle in Northern Brazil. Pedigree information concerning animals born between 1942 and 2006 were analyzed. Population structure was performed using the Endog program. Out of the 140,628 animals studied, 67.7, 14.52 and 3.18% had complete pedigree record of the first, second and third parental generation, respectively. Inbreeding and average relatedness coefficients were low: 0.2 and 0.13%, respectively. However, these parameters may have been underestimated, since information on pedigree was incomplete. The effective number of founders was 370 and the genetic contribution of 10, 50 and 448 most influent ancestors explained 13.2, 28 and 50% of the genetic variability in the population, respectively. The genetic variability for growth traits and population structure demonstrates high probability of increasing productivity through selective breeding. Moreover, management strategies to reduce the currently observed age at first calving and generation intervals are important for Nelore cattle genetic improvement.

scholarly journals Sire evaluation of milk producers’ co-operative union limited of Bangladesh

2013 ◽  
Vol 41 (2) ◽  
pp. 74-78
Author(s):  
MS Hossen ◽  
SS Hossain ◽  
AKFH Bhuiyan ◽  
MA Hoque ◽  
MAS Talukder
Keyword(s):  
Birth Weight ◽  
Genetic Variability ◽  
Genetic Improvement ◽  
Great Opportunity ◽  
Selection Scheme ◽  
Breeding Values ◽  
High Genetic Variability ◽  
Genetic Groups ◽  
Sire Evaluation

Data on 3637 cows of seven genetic groups at Baghabarighat milk shed area, from 1991 to 2000 were analyzed. The genetic groups were Pabna Milking (PM) cows, ½PM×½ Sahiwal (PM×SL), ½PM×½Frisian (PM×FN), Australian Friesian Sahiwal (AFS), ½Sahiwal×¼PM×¼ Friesian [SL(PM×FN)], ½Friesian ×¼PM×¼Sahiwal [FN(PM×SL)] and ½Friesian×¼Sahiwal×¼ Jersey [FN(SL×JR)]. The purpose of this study was to predict breeding values (PBV) of dairy sires using individual daughters performance (birth weight, lactation yield, fat% and SNF%) records at Baghabarighat milk shed area. The heritability values were estimated as 0.27±0.05 for birth weight, 0.45±0.03 for lactation yield, 0.37±0.04 for fat% and 0.46±0.01 for SNF%. The high genetic variability of birth weight, lactation yield, fat and SNF% indicates that there is a great opportunity or genetic improvement when these traits are included in a selection scheme. The first 3 top sires were 24, 14 and 20 for birth weight; sire number 19, 36 and 23 for lactation yield; sire number 16, 11 and 26 for fat % and sire number 14, 19 and 16 for SNF% were ranked on the basis of PBV.DOI: http://dx.doi.org/10.3329/bjas.v41i2.14104Bang. J. Anim. Sci. 2012. 41 (2): 74-78 

scholarly journals Androgenic studies in the production of haploids and doubled haploids in Capsicum spp.

2020 ◽  
Vol 73 (1) ◽  
pp. 9047-9056 ◽  
Author(s):  
Manuel Alejandro Sánchez ◽  
Yacenia Morillo Coronado ◽  
Ana Cruz Morillo Coronado
Keyword(s):  
Genetic Variability ◽  
Double Haploid ◽  
Genetic Improvement ◽  
Doubled Haploids ◽  
Horticultural Crop ◽  
Breeding Programs ◽  
Agronomic Characteristics ◽  
The World ◽  
Capsicum Spp ◽  
The Tropics

Capsicum spp. is a horticultural crop of agronomic interest and is considered the fourth most important vegetable in the world. It is an important nutritional and medicinal source, and its production generates employment in the tropics. In this species, the genetic variability is wide and with great potential, which has been exploited to generate outstanding varieties. Breeding programs seek different alternatives to accelerate the production of improved varieties with desirable agronomic characteristics. These objectives can be achieved with the production of haploid and double haploid plants via androgenesis or gynogenesis, being androgenesis the approach most used for paprika cultures. The purpose of this review is to present the results of different researches in obtaining haploids and doubled haploids in cultivars of Capsicum spp. and its impact on the genetic improvement of this crop. 

scholarly journals Genetic variability, character associaton and path analysis in the tamarind (Tamarindus indica L.) population of Nallur tamarind grove

2014 ◽  
Vol 12 (1) ◽  
pp. 20-25 ◽  
Author(s):  
TR Singh ◽  
R Nandini
Keyword(s):  
Genetic Variability ◽  
Seed Weight ◽  
Genetic Improvement ◽  
Fruit Weight ◽  
Direct Effects ◽  
Seed Number ◽  
Additive Gene ◽  
High Heritability ◽  
Beak Length ◽  
Positive Direct

An experiment was carried out during 2009-2010 on one hundred tamarind genotypes of the Nallur tamarind grove, a few kilometres away from Bengaluru International Airport, to investigate the genetic variability, character association and their direct and indirect effects on the fruit weight of tamarind. The genotypic coefficient of variation was high for seed weight, fibre weight, seed number, beak length and fruit weight. In all cases, phenotypic variances were higher than the genotypic variance. Moderate to high heritability as well as genetic advances were estimated for pod length, pod width, seed weight, seed number, number of ridges, number of furrows, pulp weight and fruit weight indicated that these traits was under additive gene control and selection for genetic improvement for these traits would be effective. Correlation studies revealed the highest significant association of fruit weight with seed weight followed by pulp weight, epicarp weight and seed number at genotypic and phenotypic level. Positive direct effects were produced by pulp weight and seed weight, while number of ridges had negative direct effects. The information obtained from the current studies can be used as selection criteria for genetic improvement of tamarind genotypes under study. DOI: http://dx.doi.org/10.3329/sja.v12i1.21109 SAARC J. Agri., 12(1): 20-25 (2014)

scholarly journals Genetic Divergence in Urena lobata Accessions to Quantitative Traits

2019 ◽  
Vol 11 (11) ◽  
pp. 81
Author(s):  
Lucinete Miranda Gomes ◽  
Albejamere Pereira de Castro ◽  
Therezinha de Jesus Pinto Fraxe ◽  
Pedro de Queiroz Costa Neto ◽  
Angela Maria da Silva Mendes ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Genetic Improvement ◽  
Quantitative Traits ◽  
Germplasm Collection ◽  
Clustering Method ◽  
Reliable Measure ◽  
High Heritability ◽  
Great Divergence ◽  
Phenotypic Groups ◽  
Selection Of

In this study, 14 quantitative traits were evaluated, divided into five distinct categories, related to the plants, leaves, flowers, fruits and seeds of seven Mallow accessions belonging to the NUSEC/UFAM germplasm collection. With the characteristics measured, the genetic variability of the accessions was evaluated, aiming at the genetic improvement of the culture. Through the analysis of variance, it was possible to assemble and propose the 14 agronomic descriptors, being that with the application of the clustering method (UPGMA), which generated a dendrogram of dissimilarity, it was possible to divide the seven genotypes into two distinct phenotypic groups, and their subgroups. The study showed that there is a great divergence between the accesses and the recommendation for the crossover is between the accesses ANÃ/MAC, ANÃ/MAQ and PIN/BER. The high heritability observed for the characters analyzed suggests the phenotypic value as a reliable measure for selection of the genotypes studied.

scholarly journals Results of fast neutron induced mutations in M1 and M2 generations of sorghum (Sorghum bicolour)

2007 ◽  
pp. 49-54
Author(s):  
Pál Pepó ◽  
Éva Erdei
Keyword(s):  
Genetic Variability ◽  
Leaf Area Index ◽  
Fast Neutron ◽  
Genetic Improvement ◽  
Harvest Index ◽  
Genetic Basis ◽  
Control Group ◽  
Induced Mutations ◽  
Area Index ◽  
Primary Materials

Due to climatic barriers, the genetic variability of Sorghum varieties decreases away from the gene centre, therefore hybrids cultivated in Hungary are restricted to a relatively limited genetic basis. This limited genetic basis results in a lower rate of genetic improvement, so the genetic basis of cytoplasm factors are to be extended. We enhanced the diversity of primary materials by fast neutron treatment. As a result of this treatment we detected sterile, deformed specimens with double panicles in the stock treated with a dose of 12.5 Gy in the M1 generation. Agronomically usefulspecimens were found in the stock treated with 10 Gy and 7.5 Gy doses, where the leaf area index (LAI) and Harvest- index gave higher values than those of the control group. In the stock treated with 5 Gy dose, variations were less significant. In the reseeded M2 generation we detected albino specimens with extreme chlorophyll defects in the 10 Gy Zádor stock.

scholarly journals Genetic trends of some important dairy traits of crossbred cows at Baghabarighat milk shed area in Bangladesh

2013 ◽  
Vol 41 (2) ◽  
pp. 67-73
Author(s):  
MS Hossen ◽  
SS Hossain ◽  
AKFH Bhuiyan ◽  
MA Hoque ◽  
MR Amin
Keyword(s):  
Birth Weight ◽  
Genetic Variability ◽  
Genetic Improvement ◽  
Genetic Group ◽  
Negative Trend ◽  
Genetic Trend ◽  
High Genetic Variability ◽  
Genetic Groups ◽  
Dairy Traits ◽  
Genetic Trends

Data on 3637 cows of seven genetic groups at Baghabarighat milk shed area during the period from 1991 to 2000 were analyzed. The genetic groups were Pabna Milking (PM) cows, ½PM×½ Sahiwal (PM×SL), ½PM×½Friesian (PM×FN), Australian Friesian Sahiwal (AFS), ½Sahiwal×¼PM×¼ Friesian [SL(PM×FN)], ½Friesian×¼PM×¼Sahiwal [FN(PM×SL)] and ½Friesian×¼Sahiwal×¼Jersey [FN(SL× JR)]. The purpose of this study was to estimate genetic trends of some dairy traits (birth weight, lactation yield, fat% and SNF %). The heritability values were estimated as 0.27±0.05 for birth weight, 0.45±0.03 for lactation yield, 0.37±0.04 for fat% and 0.46±0.01 for SNF %.  The genetic trends for the dairy traits were computed as average of breeding values using all data for cows born during 1991- 2000. It was observed that the genetic trend of birth weight of calves increased in PM×SL, PM×FN, AFS and FN(SL×JR) at the rate of 0.08, 0.10, 0.12 and 0.05 kg per year, respectively. The same for lactation yield of genetic group PM×FN, AFS, SL(PM×FN) and FN (SL×JR) rose up at the rate of 6.78, 5.20, 4.14 and 5.19 liters per year, respectively. The genetic group PM, PM×SL and PM×FN showed negative trend for fat % at the rate of 0.0005, 0.002 and 0.004% per year, respectively. But the same increased in AFS, SL(PM×FN), FN(PM×SL) and FN(SL×JR) at the rate of 0.002, 0.013, 0.011 and 0.004% per year, respectively. The genetic trend of SNF % in only one group showed negative trend in PM×SL at the rate of 0.01 % per year. On the contrary, PM, PM×FN, AFS, SL(PM×FN), FN(PM×SL) and FN (SL×JR) increased at the rate of 0.005, 0.010, 0.011, 0.0002, 0.014 and 0.003% per year, respectively. The high genetic variability of birth weight, lactation yield, fat and SNF% indicated that there are good opportunities for genetic improvement when including these traits in a selection scheme.DOI: http://dx.doi.org/10.3329/bjas.v41i2.14103Bang. J. Anim. Sci. 2012. 41 (2): 67-73

scholarly journals Application of the technology of improvement of body development traits as a basis for milk production in Simmental cattle population in Serbia

2006 ◽  
Vol 22 (3-4) ◽  
pp. 33-43
Author(s):  
V. Bogdanovic ◽  
Radica Djedovic ◽  
P. Perisic ◽  
M.M. Petrovic
Keyword(s):  
Genetic Variability ◽  
Milk Production ◽  
Body Length ◽  
Genetic Improvement ◽  
Cattle Population ◽  
Body Frame ◽  
Body Development ◽  
Simmental Cattle ◽  
Heritability Estimates

To analyze variability and heritability of body development traits and possibilities for their improvement data of 371 performance tested Simmental bulls were used. Average test-on (120 days of age) and test-off (365 days of age) height at withers (HW), circumference of chest (Cir), depth of chest (DC), width of round (WR), width of hip (WH) and body length (BL) were 99.88?3.49 and 126.00?2.65 cm, 127.42?6.14 and 184.76?5.95 cm, 42.55?2.25 and 60.90?2.15 cm, 32.56?3.01 and 47.63?2.67 cm, 30.26?2.12 and 44.14?1.93, 106.69?5.99 and 147.57?4.65 cm, respectively. Average values for test-on and test-off index of body frame (IBF), index of chest depth (ICD), index of body compactness (ICBL), and index of massiveness (IM) were 106.8?4.44 and 117.13?3.11%, 42.61?1.90 and 48.34?1.45%, 119.59?5.19 and 125.27?4.26%, 127.58?4.86 and 146.65?4.30%, respectively. Heritability estimates for test-off height at withers, circumference of chest, depth of chest and body length were 0.43, 0.30, 0.33 and 0.29. Possibilities for improvement of body development traits were done according to their phenotypic and genetic variability. Obtained results confirm that exist enough variability in major body development traits in Simmental bulls which can be utilized not only for genetic improvement of milk production in their daughter, but also for improvement of overall body traits in Simmental population in Serbia.

scholarly journals Variabilidade genética e coeficiente de determinação em genótipos de algodoeiro quanto a qualidade da fibra

2015 ◽  
Vol 10 (3) ◽  
pp. 66 ◽  
Author(s):  
D. O. C. Bonifácio ◽  
F. M. Mundim ◽  
L. B. Sousa
Keyword(s):  
Genetic Variability ◽  
Textile Industry ◽  
Genetic Improvement ◽  
Fiber Quality ◽  
High Volume ◽  
Coefficient Of Determination ◽  
Feature Variability ◽  
Cotton Genotypes ◽  
Fiber Maturity

O algodão é a mais importante fibra têxtil do mundo e a sua qualidade é o que garante o retorno investido pelo produtor. O trabalho teve como objetivo avaliar a variabilidade genética entre 22 genótipos de algodoeiro de fibra branca do Programa de Melhoramento Genético do Algodoeiro, da Universidade Federal de Uberlândia, quanto a qualidade da fibra e determinar o coeficiente de determinação genotípico dos caracteres. O experimento foi realizado na fazenda Capim Branco, em Uberlândia-MG, na safra 2012/2013. O delineamento experimental foi de blocos casualizados com três repetições. Avaliou-se 20 genótipos de algodoeiro. Com o auxílio do aparelho High Volume Instrument, determinou-se o índice de consistência a fiação, índice micronaire, maturidade da fibra, comprimento da fibra, uniformidade de comprimento, índice de fibras curtas, resistência, alongamento, reflectância e grau de amarelecimento. As linhagens do Programa de Melhoramento genético do Algodoeiro da Universidade Federal de Uberlândia, com exceção da UFUJP13-17 e UFUJP13-20, atendem as exigências da indústria têxtil e apresentam variabilidade suficiente para seguir no processo de melhoramento. A variação entre os genótipos foi em maior parte de natureza genética, com coeficiente de determinação acima de 80%.Genetic variability and coefficient of determination in cotton genotypes as the quality of the fiberAbstract: Cotton is the most important textile fiber in the world and its quality is what ensures the return invested by the producer. The objective of this work was to evaluate the genetic variability among 22 genotypes of cotton fiber white of the Program of Genetic Improvement of Cotton, from the Federal University of Uberlandia, as fiber quality and determine the coefficient of determination of genotypic characters. The experiment was carried out on the farm Capim Branco, in Uberlandia, MG, in season 2012/2013. The experimental design was a randomized complete block with three replications. Evaluated 20 cotton genotypes. With the aid of the appliance High Volume Instrument, it was determined that the index of consistency the wiring, index micronaire, fiber maturity, fiber length, length uniformity index of short fibers, strength, elongation, reflectance and degree of yellowing. The lines of the Program of genetic improvement of cotton from the Federal University of Uberlandia, with the exception of UFUJP13-17 and UFUJP13-20, meet the requirements of the textile industry and feature variability sufficient to follow in the process of improvement. The variation between the genotypes was in most of nature genetics, with coefficient of determination above 80 %.

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