Changes in the components of phenotypic variance and covariance among traits during ontogeny in the sharp-snouted rock lizard (Lacerta oxycephala)

1994 ◽  
Vol 15 (1) ◽  
pp. 47-61 ◽  
Author(s):  
I. Aleksic ◽  
N. Tucic

AbstractWe estimated changes in the components of phenotypic variance and covariance among seven metric traits over the first 90 days of growth in the sharp-snouted rock lizard (Lacerta oxycephala). The broad-sense heritability estimated from the data representing mostly size components of the seven morphometic traits over four age periods was about 90%. The average broad-sense heritability for the shape components of the same traits and age periods amounted to about 42%. By using bivariate and multivariate statistical methods, ontogenetic allometry coefficients have been estimated. The average heritability estimated for the bivariate allometric coefficients was about 69%. Genetic correlation structures were highly integrated within each age period and this integration increased from newborn lizards to lizards aged up to 90 days. For absolute measurements, phenotypic correlation structures were less integrated than genetic correlation structures, while for size-free measurements the opposite trend was observed.

2021 ◽  
Author(s):  
Ghasem Eghlima ◽  
Mohsen Sanikhani ◽  
Azizollah Kheiry ◽  
Javad Hadian

Abstract Glycyrrhiza glabra L. is an herbaceous, perennial plant with high distribution in Iran. Genetic variability, heritability and correlation among characters in 22 populations of G. glabra L. were studied. The genetic parameters among the traits including phenotypic variances, genotypic variances, genotype by environment variances, broad-sense heritability and genotypic and phenotypic correlation coefficients were studied. Variance components analysis showed that the extent of phenotypic coefficient of variation (PCV) was fairly higher for all the examined traits compared with genotypic coefficient of variation (GCV). Glabridin (GLA) exhibited high GCV and PCV (156.07% and 156.68%, respectively). The broad sense heritability varied from 38.92–99.79% and narrow sense heritability ranged from 9.70 % to 24.94%. Heritability of GLA, glycyrrhizic acid (GLY), liquiritin (LI), liquiritigenin (LIQ), rutin (RU) and rosmarinic acid (RA) were very high, exhibiting more than 97% heritability. Therefore, these critical characteristics can efficiently be selected and inherited in breeding programs. In most traits, the genotypic correlations showed the same direction as the phenotypic correlations. The contents of GLA and LIQ showed a positive correlation with majority of morphological traits. Therefore, selecting individual plants having desired morphological traits can be correlated with high contents of bioactive compounds in the harvested root.


Genetika ◽  
2010 ◽  
Vol 42 (3) ◽  
pp. 501-512 ◽  
Author(s):  
Kadri Bozokalfa ◽  
Eşiyokhülya İlbi ◽  
Kaygisiz Aşçioğul

Despite the increasing of economical importance of rocket plant limited information is available on genetic variability for the agronomic traits among Eruca spp. Hence, heritability and association studies of plant properties are necessities for a successful further rocket breeding programme. The objective of this study was to examine phenotypic and genotypic variability, broad sense heritability, genetic advance, genotypic and phenotypic correlation and mean for agronomic traits of rocket plant. The magnitude of phenotypic coefficient of variation values for all the traits were higher than the corresponding values and broad sense heritability estimates exceeded 65% for all traits. Phenotypic coefficients of variability (PCV) ranged from 7.60 to 34.34% and genotypic coefficients of variability (GCV) ranged between 5.58% for petiole thickness and 34.30% for plant weight. The results stated that plant weight, siliqua width, seed per siliqua and seed weight could be useful character for improved Eruca spp. breeding programme.


2016 ◽  
Vol 47 (4) ◽  
Author(s):  
S. J. Bunder

The objective of this study was estimation of variances, broad sense heritability genotypic and phenotypic correlation for some traits of  maize  under  nitrogen abundance . the experiment was conducted at the farm of the Dept. of  Field Crop Sci., College of Agric., Univ. of  Baghdad during the Spring and fall seasons of 2012 under level 400 Kg N. ha rate-1 . Diallel cross was performed among four maize inbred lines (Zm7, Zm607, Oh40, Zr8) to produce six single crosses in spring season . The seeds of parents and crosses were sown in fall season using R.C.B.D. with three replicates. The results showed significant difference among genotypes and the values of the genotypic variance were more than environment variance in all studied characters. The values of phenotypic coefficients of variation larger than the genotypic and the higher rate of genotypic coefficient of variation for 300 grain weight 16.74, no. of grain per row 15.05 and leaves area 12.18. furthermore high estimates of broad sense heritability were observed for all characters and the highest value 81.45 for 300 weight grain and 75.31 for leaves area .The grain yield gave high significant negative genotypic and phenotypic with silking date and positive with plant height , leaves area , no. of grain per row , 300 grain weight. It was concluded that a breeder can use leaves area , no. of grain per row and grain weight as selection index  in selection program of  maize under high nitrogen


2022 ◽  
Vol 951 (1) ◽  
pp. 012103
Author(s):  
E Kesumawati ◽  
Sabaruddin ◽  
E Hayati ◽  
N Hadisah ◽  
R Hayati ◽  
...  

Abstract Pepper is widely cultivated as a condiment and cash crop in Indonesia. However, Pepper yellow leaf curl disease (PepYLCD) caused by begomovirus is currently seriously affect the domestic pepper production. Breeding for begomovirus resistance material by crossing is currently necessary to overcome the constraint. The present study is aimed to determine the resistance of pepper (C. annuum) plants F2 progenies to begomovirus infection in the growth stage. Two local C. annuum accessions, BaPep-5 as a resistance donor for pepy-1 begomovirus resistance gene (locally called Perintis) and BaPep-4 as a susceptible parent (locally called Kencana) were crossed to generate F2 progenies. The research was conducted in Agricultural Extension Training Centre (BLPP) Saree and Horticulture Laboratory of Syiah Kuala University from February to July 2020. 500 F2 progenies were transplanted to the field along with 15 plants of each parent as control. The result suggested that plant height and crown width had the highest broad sense heritability value, whereas the dichotomous height, stem diameter, secondary branch, and tertiary branch had the lowest broad sense heritability value. Coefficient of genetic variance and coefficient of phenotypic variance from overall characteristics were relatively low which suggest the narrow sense to slightly narrow sense heritability.


2005 ◽  
Vol 95 (11) ◽  
pp. 1301-1307 ◽  
Author(s):  
J.-M. Thevenin ◽  
R. Umaharan ◽  
S. Surujdeo-Maharaj ◽  
B. Latchman ◽  
C. Cilas ◽  
...  

Field observations were conducted from 1998 to 2001 at the International Cocoa Genebank, Trinidad, to evaluate 57 cacao clones for resistance to black pod (BP) and witches'-broom (WB) diseases (caused by Phytophthora sp. and Crinipellis perniciosa, respectively). Each month ripe pods were harvested and the number of healthy and diseased was recorded. The number of brooms on vegetative shoots was recorded three times a year on selected branches. Twenty-three clones showed less than 10% of infection for both BP and WB on pods. Among those, eight clones showed an absence of brooms on the observed branches: IMC 6, MAN 15/60 [BRA], PA 67 [PER], PA 195 [PER], PA 218 [PER], PA 296 [PER], PA 303 [PER], and POUND 32/A [POU]. Broad-sense heritability was estimated at 0.38 and 0.57 for WB disease on pods and shoots, respectively, and at 0.51 for BP disease. Genetic correlation between WB disease on pods and on shoots was low and estimated at 0.39, whereas the correlation between WB and BP diseases on pods was 0.48. To choose putative parents for breeding schemes, it is suggested that clones are first assessed for their level of resistance to WB on shoots, and the most promising individuals are screened for BP with a detached pods test. Further studies are needed to confirm whether the level of resistance to WB on pods can be predicted using an early test on seedlings.


Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1409-1416 ◽  
Author(s):  
Kenneth R Koots ◽  
John P Gibson

Abstract A data set of 1572 heritability estimates and 1015 pairs of genetic and phenotypic correlation estimates, constructed from a survey of published beef cattle genetic parameter estimates, provided a rare opportunity to study realized sampling variances of genetic parameter estimates. The distribution of both heritability estimates and genetic correlation estimates, when plotted against estimated accuracy, was consistent with random error variance being some three times the sampling variance predicted from standard formulae. This result was consistent with the observation that the variance of estimates of heritabilities and genetic correlations between populations were about four times the predicted sampling variance, suggesting few real differences in genetic parameters between populations. Except where there was a strong biological or statistical expectation of a difference, there was little evidence for differences between genetic and phenotypic correlations for most trait combinations or for differences in genetic correlations between populations. These results suggest that, even for controlled populations, estimating genetic parameters specific to a given population is less useful than commonly believed. A serendipitous discovery was that, in the standard formula for theoretical standard error of a genetic correlation estimate, the heritabilities refer to the estimated values and not, as seems generally assumed, the true population values.


2001 ◽  
Vol 58 (1) ◽  
pp. 119-123 ◽  
Author(s):  
Austeclínio Lopes Farias Neto ◽  
José Branco de Miranda Filho

Full-sib and selfed (S1) progenies were obtained from sub-populations of ESALQ-PB1, divergently selected for tassel size (T+ and T-) and ear height (E+ and E-), and used for estimating genetic and phenotypic correlation coefficients between traits. The analyzed traits were: EW- total ear weight (g/plant), PH- plant height (cm), EH- ear height (cm), TB- tassel branch number and TL- tassel length. The highest genetic (rG) and phenotypic (rF) correlation was observed for the combination PH x EH, as expected, with average of 0.800 and 0.778, respectively over sub-populations and locations. It is apparent that divergent selection for tassel size did not affect greatly the correlation between PH and EH in the full sib progenies, but in the inbred progenies the correlation was smaller in the sub-population selected for larger tassels. Genetic correlation between PH and EH with tassel traits was always positive but ranged from 0.020 to 0.668 in Piracicaba and from 0.06 to 0.309 in Rio Verde. Genetic correlation between PH and EH with yield (EW) also was positive in the range of 0.087 to 0.503. EH showed higher correlation with EW in relation to PH x EW and differences were larger in the sub-populations divergently selected for ear height. Correlation between tassel traits with other traits was positive in most of instances and a lack of consistency was observed among sub-populations. Generally the coefficients of genetic and phenotypic correlation differed substantially from the estimates in the base population ESALQ-PB1 before divergent selection for tassel size and ear placement. Divergent selection affected the correlation between traits under unpredicted and varying magnitudes.


2004 ◽  
Vol 34 (2) ◽  
pp. 505-510 ◽  
Author(s):  
Marcelo Renato Alves de Araújo ◽  
Bruce Coulman

Meadow bromegrass (Bromus riparius Rehm.) is a recently introduced pasture grass in western Canada. Its leafy production and rapid regrowth have made it a major grass species for pasturing beef animals in this region. As relatively little breeding work has been done on this species, there is little information on its breeding behaviour. The main objective of this study was to estimate total genetic variability, broad-sense heritability, phenotypic and genetic correlations. Forty-four meadow bromegrass clones were evaluated for agronomic characters. Genetic variation for dry matter yield, seed yield, fertility index, harvest index, plant height, plant spread, crude protein, neutral detergent fiber and acid detergent fiber, was significant. Broad-sense heritability estimates exceeded 50% for all characters. Heritability estimates were at least 3.5 times greater than their standard errors. Phenotypic and genetic correlation between all possible characters were measured. There was general agreement in both sign and magnitude between genetic and phenotypic correlations. Correlations between the different characters demonstrated that it is possible to simultaneously improve seed and forage yield. Based on the results, it appears that the development of higher yielding cultivars with higher crude protein, and lower acid and neutral detergent fibers concentration should be possible.


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