scholarly journals Genetic variability and correlation analysis in hybrids of mulberry silkworm, Bombyx mori L. for egg characters

1970 ◽  
Vol 27 ◽  
pp. 13-16 ◽  
Author(s):  
Md Kamrul Ahsan ◽  
SM Rahman

The genotypic variability and correlation coefficients were studied in thirty five hybrid populations for five egg characters. Variations among genotypes were highly significant (P < 0.001). Phenotypic coefficient of variation was higher than genotypic coefficient of variation for all the characters. Of them unfertilized and dead egg percentage showed highest difference between genotypic and phenotypic coefficient of variation suggesting most influence of environment on these characters. Majority of the characters showed high heritability except hatching percentage. Furthermore total number of egg laying per female showed high genetic advance together with high heritability, which indicates the importance of additive gene effect of this character. The genotypic correlations were higher than phenotypic correlation for majority of the characters under study except DEP Vs TEL and DEP Vs UEP. These low phenotypic correlations could be due to a modifying effect of environment and the association of characters at genotypic level. Hatching percentage, blue egg percentage and unfertilized egg percentage showed both positive and negative significant correlation to each other. Therefore, proper attention should be given to these characters specially total number of egg laid by female and hatching percentage in selection programme for genetic gain in Bombyx. mori. Key words: Genetic variability, correlation, B. mori.   doi:10.3329/ujzru.v27i0.1946   Univ. j. zool. Rajshahi Univ. Vol. 27, 2008 pp. 13-16

2013 ◽  
Vol 31 ◽  
pp. 19-22
Author(s):  
M Kamrul Ahsan

The genotypic variability and correlation coefficients were studied in 27 indigenous multivoltine varieties of mulberry silkworm, B. mori L. for six egg characters. The genotype was highly significant for all the characters under studied. Least difference between genotypic and phenotypic coefficient of variation were observed. Majority of the characters showed high heritability comparing with dead egg percentage. Furthermore Unfertilized egg percentage showed high genetic advance together with high heritability but HP and EW showed high heritability and low genetic advance. These indicate the importance of additive and non-additive gene effect of these characters respectively. Total number of egg laid by female, hatching percentage, and blue egg percentage showed both positive and negative significant correlation to each other at both the phenotypic and genotypic levels. The results suggest that these characters specially total number of egg laid by female, blue egg percentage and unfertilized egg percentage appeared as importance in selection programme for genetic gain in B. mori.DOI: http://dx.doi.org/10.3329/ujzru.v31i0.15375Univ. j. zool. Rajshahi Univ. Vol. 31, 2012 pp. 19-22


2012 ◽  
Vol 30 ◽  
pp. 33-36
Author(s):  
Md Ariful Hasan ◽  
Sawdagar Mahfuzar Rahman ◽  
Md Kamrul Ahsan

The genotypic variability and heritability for nine quantitative characters in 65 varieties of silkworm, B. mori L. have been investigated. Variation among genotypes were highly significant (p<0.001) for all the characters indicating the existence of a real difference among the genotypes which are suitable for breeding purposes. The highest heritability was obtained for shell weight followed by filament size (FS), filament length (FL), expected cocoon yield out of 100 dfls (ECY), surviving percentage of larvae (SPL), cocoon weight (CW), egg hatching percentage (EHP) and mature larval weight (MLW). Comparatively high heritability accompanied by a genetic advance was recorded for FL and total number of eggs laid per female (TEL) indicating the importance of additive gene effects of these characters, but shell weight, cocoon weight and filament size showed high heritability and low genetic advance indicating the involvement of non-additive gene systems in the inheritance of these characters. So selection on the basis of these characters, with relatively more emphasis upon filament length and total number of eggs laid per female to obtain high yielding varieties of B. mori is suggested. DOI: http://dx.doi.org/10.3329/ujzru.v30i0.10744 Univ. j. zool. Rajshahi Univ. Vol. 30, 2011 pp.33-36


2017 ◽  
Vol 15 (1) ◽  
pp. 15-19
Author(s):  
MM Rashid ◽  
M Nuruzzaman ◽  
L Hassan ◽  
SN Begum

An experiment was conducted using a randomized complete block design to estimate genetic variability of ten rice genotypes. Analysis of variance for yield and yield contributing traits showed significant (p<0.01) variation among the genotypes. Results of genetic analyses showed a higher phenotypic coefficient of variation compared to their corresponding genotypic coefficient of variation for all the traits measured, which indicates that the traits were influenced by environment. The magnitude of difference between phenotypic coefficient of variance (PCV) and genotypic coefficient of variance (GCV) was less for the traits indicating little influence of environment. The higher estimates of PCV and GCV were observed for number of filled grains panicle–1 (27.53; 26.84), number of unfilled grains panicle–1 (26.76;25.28) and plant height (23.14; 23.00) indicates possibility of genetic improvement through direct selection for these traits, while days to 50% flowering, days to maturity, panicle length, number of effective tillers plant–1, fertility (%), 1000 Seed weight and yield panicle–1 showed low PCV and GCV values indicating the need for creation of variability by hybridization or mutation followed by selection. High heritability values (>60%) along with high genetic advance and genetic advance as percentage of mean were found for all the traits indicating prevalence of additive gene action, which provides good scope for further improvement by selection.J. Bangladesh Agril. Univ. 15(1): 15-19, January 2017


1970 ◽  
Vol 5 ◽  
pp. 43-46
Author(s):  
Md Kamrul Ahsan ◽  
Sowdagar Mahfuzar Rahman ◽  
Md Tajimul Haque

Genetic variability, heritability and correlation analysis for some important economic characters in 35 hybrids of the silkworm, Bombyx mori L. have been investigated. Higher heritability values were recorded for effective rate of rearing by number (ERRn), followed by estimated cocoon yield per 100 dfls (ECY), weight of mature larvae (WML), filament length (FL) and effective rate rearing by weight (ERRw). Furthermore, characters such as FL, ERRn, ERRw and ECY showed higher genetic advance coupled with higher heritability values, indicating the importance of additive gene effect of these characters. The genotypic correlations were higher than the phenotypic correlations for all the characters under study. These low phenotypic correlations could be due to a modifying effect of environment of the association of characters at genotypic level. Most of the characters showed positive significant correlation to each other except ERRn and ERRw pair at phenotypic level. Therefore, proper attention should be given to these characters, especially WML, FL and ECY, in selection programmes for genetic gain in B. mori. Key words: Genetic variability; heritability; correlation; economic characters; B. mori. DOI: 10.3329/jles.v5i0.7349 J. Life Earth Sci., Vol. 5: 43-46, 2010  


2018 ◽  
Vol 10 (1) ◽  
pp. 375-378
Author(s):  
Biswaranjan Behera ◽  
Simanchal Sahu ◽  
Rajesh Kumar Kar ◽  
Ritu Kumari Pandey

An experiment was conducted to study genetic variability in forty-nine elite slender grain rice genotypes for thirteen component characters including grain yield.The experimental materials possessed a considerable amount of variability for all the traits. Majority of the traits showed the smaller difference between phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV). Both PCV and GCV were high for grain yield (gm) (PCV:27.14%, GCV:26.27%), and fertile grains per panicles(PCV:20.61%, GCV:20.52%), indicating less effect of environment on these characters. PCV and GCV were moderate for characters like harvest index (PCV:16.99%, GCV: 14.18%), 100 seed weight (gm) (PCV:14.57%, GCV:13.82%), fertility percentage (PCV:15.72%, GCV:15.05%), flag leaf area (cm2 ) (PCV:17.83%, GCV: 17.74%) and days to 50 % flowering (PCV:11.20%, GCV:11.17%) indicating that there is considerable amount of environmental effect on such characters. Moderate to a high degree of heritability estimates were observed for the majority of the traits under study except for a number of effective tillers/plant indicating the low or negligible influence of environment in the expression of these traits and may respond to selection for their improvement. High heritability (H2 )estimates were associated with moderate to high genetic gain over mean (GAM) for days to 50% flowering (H2 : 99.35%,GAM: 19.52%), plant height (H2 :93.89%,GAM:14.01%), panicle length (H2 :94.06%,GAM:14.04%), flag leaf area(H2 : 98.93%,GAM: 31.05%), fertile grains/panicle (H2 :99.20%,GAM: 35.98%), fertility percentage (H2 :91.57%,GAM:25.34%),100 seed weight (H2 :89.90%,GAM:23.06%)and grain yield per plant (H2 :93.71%,GAM:44.76%) indicating the presence of additive gene effect and hence selection based on phenotypic performance for these traits would be effective.


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.


2015 ◽  
Vol 26 (2) ◽  
pp. 15-22
Author(s):  
S. Parveen Parveen ◽  
M. H. Rashid Rashid ◽  
M. S. R. Bhuiyan

The field experiment was conducted to estimate the genetic variability and correlation between yield contributing traits using 15 rape seed genotypes. The results indicated that the phenotypic variance for all the characters was considerably higher than the genotypic variance denoting little influence of environmental factors on their expression. Characters like 1000-seed weight (12.39, 14.10), days to 50% flowering (18.36, 18.77) and days to maturity (4.63, 5.06) showed low genotypic and phenotypic coefficient of variation. Moderate genotypic and phenotypic coefficient of variation was observed in number of primary branches per plant (20.22, 22.16), length of siliqua (20.84, 20.97), number of seeds per siliqua (30.90, 33.06), number of siliquae per plant (49.34, 49.81) and yield per plant (34.36, 39.98) and high genotypic (67.00) and phenotypic coefficient of variation (68.57) was observed for number of secondary branches per plant. Plant height (85.98%, 30.89), 1000 seed weight (77.14%, 22.41), days to 50% flowering (95.66%, 20.35) and days to maturity (83.85%, 7.82) showed high heritability with low genetic advance which indicated the possibility of non-additive gene action. Number of primary branches per plant (83.22%, 37.99, 636.02), length of siliqua (98.83%, 42.68, 1084.42), number of seeds per siliqua (87.40%, 59.52, 424.22), number of siliqua per plant (98.15%, 100.71, 178.83) and yield per plant (73.87%, 60.84, 4539.97) showed high heritability with high genetic advance and high genetic advance in percentage of mean revealed the possibility of predominance of additive gene effects. Number of primary branches per plant had showed highly significant positive association with number of secondary branches per plant (rg=0.597, rp= 0.537) and yield per plant (rg=0.43). Days to 50% flowering showed significant positive association with seeds per siliqua (rg=0.492; rp=0.436), 1000 seed weight (rg=0.486; rp=0.472) and yield per plant (rg=0.438; rp=0.379). Length of siliqua manifested highly significant positive association with siliqua per plant (rg=0.571; rp=0.514) and significant negative association with yield per plant (-0.471) at genotypic level. Siliqua per plant had highly significant negative association at both genotypic and phenotypic level with yield per plant (-0.697; -0.525) but 1000 seed weight had highly significant positive association with yield per plant both genotypic and phenotypic level (0.893; 0.814). The results of the path analysis revealed that 1000 seed weight (0.766) had the maximum direct effect and the maximum negative direct effect was observed in seeds per siliqua (0.305). In summary, the results suggested that there were some yield related traits such as 1000 seed weight and days to 50% flowering could be selected and used in breeding program for increasing the grain yield of rapeseed.


2019 ◽  
Vol 22 (1) ◽  
pp. 35-43
Author(s):  
MZ Islam ◽  
T Chakrabarty ◽  
N Akter ◽  
ESMH Rashid ◽  
M Khalequzzaman ◽  
...  

The success of varietal development programmme largely depends on the nature and magnitude of genetic variability, heritability and characters association of the crop. The objective of the present study was to estimate the extent of genetic variability and relation between yield and related characters of rice. Forty Boro rice germplasm were evaluated in a randomised complete block design with three replications. Analysis of variance indicated significant differences among the genotypes for 14 quantitative characters. The presence of slightly higher phenotypic coefficient of variation than genotypic coefficient of variation indicated the negligible influence of environment on the expression of yield and its component traits. Leaf length, days to flowering, days to maturity and 1000 grain weight showed highly positive significant correlation present with yield hill-1. High heritability had been observed for yield contributing traits during the study, suggested that these traits would respond to selection owing to their high genetic variability and transmissibility. Therefore, a thorough understanding of the inheritance of traits, their heritability and relationship with other important characteristics is important for the choice of breeding and selection methods for crop improvement. Bangladesh Rice j. 2018, 22(1): 35-43


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Massaoudou Hamidou ◽  
Abdoul Kader M. Souley ◽  
Issoufou Kapran ◽  
Oumarou Souleymane ◽  
Eric Yirenkyi Danquah ◽  
...  

Sorghum is the second most important cereal crop in Niger. The crop is grown in a wide range of ecological environments in the country. However, sorghum grain yield in Niger is limited by both abiotic and biotic constraints. Recombinant inbred lines derived from the cross of a local variety with a midge resistant variety and two local checks were evaluated during the 2015 rainy season across two planting dates in two environments in Niger. The objective was to investigate genetic variability for yield, yield related traits, and resistance to sorghum midge. High phenotypic coefficient of variation (PCV) versus genotypic coefficient of variation (GCV) was observed in both sites and planting dates. Across planting dates at both Konni and Maradi, grain yield, plant height, panicle weight, and midge damage had high heritability coupled with high estimates of genetic advance. At Konni, high genetic advance coupled with high heritability was detected for grain yield, plant height, panicle weight, and resistance to midge. There were similar results at Maradi for grain yield, plant height, and panicle weight. Therefore, selection might be successful for the above characters in their respective environments.


Author(s):  
Ajay Chauhan ◽  
Akhilesh Sharma ◽  
Parveen Sharma ◽  
Viveka Katoch ◽  
Sanjay Chadha ◽  
...  

Background: Edible podded pea is an oriental vegetable crop which shares the cultivation pattern with the garden pea. Fresh tender pods lacking parchment layer are consumed whole like beans. It is a newly introduced crop in India and therefore, it would be imperative to identify the most promising genotypes vis-à-vis traits of interest, those contributing towards maximization of yield. The present investigation was, therefore, planned to assess the genetic parameters of variability for pod yield and related horticultural traits in order to identify the most promising edible pod pea genotypesMethods: Thirty six genotypes comprising of 29 F7 advanced breeding lines and nine lines from different institutes including three checks namely, ‘Arka Apoorva’, ‘Arka Sampoorna’ and ‘Mithi Phali’ were evaluated in randomized complete block design over three replications during winters 2016-2017 at C.S.K. Himachal Pradesh Krishi Vishvavidyalaya, Palampur for pod yield and related horticultural traits.Result: Sufficient genetic variability was observed for all morphological and yield contributing attributes. The magnitude of phenotypic (PCV) and genotypic (GCV) coefficients of variation were high for pod yield while branches per plant, internodal length, harvest duration and pods per plant showed high PCV and moderate GCV. High heritability along with high genetic advance was observed for internodal length, plant height, average pod weight and pod yield per plant indicating the importance of additive gene action. Pod yield per plant revealed positive correlation at both phenotypic and genotypic levels with pods per plant, average pod weight, pod length and pod breadth. Pods per plant and average pod weight at both phenotypic and genotypic levels had maximum positive direct and indirect effects to the total association of component traits suggesting the importance of these traits towards pod yield. 


Sign in / Sign up

Export Citation Format

Share Document