scholarly journals Molecular Markers for Biomass Traits: Association, Interaction and Genetic Divergence in Silkworm Bombyx mori

2007 ◽  
Vol 2 ◽  
pp. 117727190700200 ◽  
Author(s):  
Appukuttannair R Pradeep ◽  
Anuradha H Jingade ◽  
Raje S Urs
Keyword(s):  
Bombyx Mori ◽  
Diversity Index ◽  
Natural Populations ◽  
Inter Simple Sequence Repeat ◽  
Issr Markers ◽  
Mean Value ◽  
Stepwise Multiple Regression ◽  
Shell Weight ◽  
Polygenic Control ◽  
Silkworm Bombyx Mori

Improvement of high yielding, disease resistant silkworm strains became imminent to increase production of silk, which is a major revenue earner for sericulturists. Since environment interacts with phenotype, conventional breeding did not result in commendable yield improvement in synthetic strains of silkworm, Bombyx mori. Identification of DNA markers associated with different economically important biomass traits and its introgression could assist molecular breeding and expression of stabilized high yielding characters, but genetic basis of most quantitative traits in silkworm is poorly understood due to its polygenic control. Correlation analysis (R = 0.9) revealed significant interrelation among biomass traits viz., larval duration (TLD), larval weight (LWT), cocoon weight (CWT), shell weight (SWT), shell ratio (SR) and floss content. PCR using inter simple sequence repeat (ISSR) primers revealed 92% polymorphism among 14 tropical and temperate strains of B. mori, with average diversity index of 0.747. Stepwise multiple regression analysis (MRA) selected 35 ISSR markers positively or negatively correlated with different biomass traits, illustrated polygenic control. ISSR marker 830.81050bp was significantly associated with LWT, CWT, SWT, SR and floss content, indicated its pleiotropic role. Two ISSR markers, 835.51950bp and 825.9710bp showed significant association with floss content and TLD. These markers were segregated in F2 generation and Chi-square test confirmed (χ2 = ~45; P < 0.05) its genetic contribution to the associated biomass traits. Strains, with both positively and negatively correlated markers, had intermediate mean value for biomass traits (eg. SWT = 0.17 ± 0.014 g in GNM and Moria) indicated interaction of loci in natural populations. Low yielding Indian strains grouped together by Hierarchical clustering. Chinese and Japanese strains were distributed in the periphery of ALSCAL matrix indicated convergence of genetic characters in Indian strains. Average genetic distance between Chinese strains and Indian strains (0.193) significantly ( P < 0.01) varied from that between Chinese and Japanese strains. Interaction of loci and allelic substitutions induced phenotypic plasticity in temperate B. mori populations on tropic adaptation in India. These outcomes show possibility to combine favorable alleles at different QTL to increase larval, cocoon and shell weight.

Comparison of the genetic diversity in two species of cycads

2005 ◽  
Vol 53 (3) ◽  
pp. 219 ◽  
Author(s):  
Longqian Xiao ◽  
Xun Gong ◽  
Gang Hao ◽  
Xuejun Ge ◽  
Bo Tian ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Simple Sequence Repeat ◽  
Inter Simple Sequence Repeat ◽  
Issr Markers ◽  
Mean Value ◽  
The Mean ◽  
The Difference ◽  
General Opinion ◽  
Simple Sequence ◽  
Striking Contrast

Inter-simple sequence repeat (ISSR) markers were used to examine the level and distribution of genetic diversity in two cycad species: Cycas parvula S.L.Yang and C. balansae Warburg. The former is found in only two adjacent populations and the latter in a relatively wider distribution. Although genetic diversity in C. balansae (He = 0.1301) is higher than that in C. parvula (He = 0.0538), both are still low in comparison with the mean value (He = 0.169) in gymnosperms. This confirms the general opinion that cycads are genetic relics. The genetic differentiation in both species, however, presents a striking contrast: Gst is 0.0978 in C. parvula, but 0.4003 in C. balansae, which may be ascribed to the difference in distances between their populations.

scholarly journals Low Divergence Among Natural Populations of Cornus kousa subsp. chinensis Revealed by ISSR Markers

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1082 ◽  
Author(s):  
Jia-Qiu Yuan ◽  
Qin Fang ◽  
Guo-Hua Liu ◽  
Xiang-Xiang Fu
Keyword(s):  
Genetic Diversity ◽  
Diversity Index ◽  
In Situ Conservation ◽  
Geographic Distance ◽  
Natural Populations ◽  
Issr Markers ◽  
Mantel Test ◽  
Distribution Area ◽  
Genetic Characteristics ◽  
Cornus Kousa

Research Highlights: Taking Chinese dogwood (Cornus kousa subsp. chinensis) as an example, the genetic characteristics of natural populations collected from main a distribution area were evaluated using intersimple sequence repeat (ISSR) markers to reveal the genetic basis for further selection and breeding. Background and Objectives: Chinese dogwood is a small understory tree that is widely distributed in China. Chinese dogwood has attracted interest for its potential horticultural and ornamental values, and its natural resource potential urgently needs to be estimated. Materials and Methods: In this study, the genetic diversity of 12 natural populations collected from six provinces containing 223 individuals was evaluated based on ISSR markers. Results: Relatively high levels of genetic diversity were found at both the population and individual levels. The Shannon’s diversity index (I) among individuals (0.504) was higher than that among populations (0.338). Analysis of molecular variance (AMOVA) revealed that genetic variation mainly existed within populations (61.55%) rather than among populations (38.45%). According to the STRUCTURE analysis, 12 populations were assigned to two groups, i.e., the northern and southern ecological regions, which are separated by the Yangtze River. A Mantel test analysis showed that there was no significant correlation between genetic distance and geographic distance. Conclusions: Considering the breeding system of dogwoods, we speculated that the genetic characteristics of the natural populations of this species would be affected by the dispersal mode of its pollens and seeds; additionally, genetic drift could play an important role in its genetic differentiation. In conclusion, in situ conservation is recommended for Chinese dogwood based on our results.

Seasonal Variations in the Silk Yield Contributing Characters of Forty-two Strains of the Silkworm, Bombyx mori (Lepidoptera: Bombycidae)

1995 ◽  
Vol 30 (3) ◽  
pp. 297-311
Author(s):  
S. K. Bhargava
Keyword(s):  
Bombyx Mori ◽  
Economic Value ◽  
Filament Length ◽  
Shell Weight ◽  
Pupation Rate ◽  
Bombyx Mori L ◽  
And Training ◽  
Silk Filament ◽  
Training Institute ◽  
Silkworm Bombyx Mori

Forty-two strains of the silkworm, Bombyx mori (L.), collected from China, Japan, Vietnam, South Korea, Brazil, India, and France were reared in the spring, summer and autumn seasons during 1991–92 at the Regional Station of Central Sericultural Research and Training Institute, Coonoor, Tamilnadu State, India. Analyses were made on five silk yield-contributing characters, namely pupation rate, cocoon weight, shell weight, cocoon shell ratio, and silk filament length. Results indicated the superiority of the following strains for all the above mentioned characters: 14M and JC2P (in spring); NBJPO and JC2P (in summer); and M2, NBJPO and SPJ2 (in autumn). The importance of rearing a given strain of silkworm in the optimal season for its maximum economic value in terms of silk yield is discussed.

scholarly journals Analysis of genetic diversity among different tomato genotypes using ISSR DNA marker

Genetika ◽  
2017 ◽  
Vol 49 (1) ◽  
pp. 31-42
Author(s):  
Saida Sharifova ◽  
Sabina Mehdiyeva ◽  
Mehraj Abbasov
Keyword(s):  
Genetic Diversity ◽  
Dna Marker ◽  
Diversity Index ◽  
Inter Simple Sequence Repeat ◽  
Issr Markers ◽  
Similarity Coefficient ◽  
Variation Analysis ◽  
A Value ◽  
Polymorphic Bands ◽  
Simple Sequence

Inter simple sequence repeat (ISSR) markers were used for variation analysis among 41 tomato accessions. A total of 50 scorable bands were obtained, where 32 were polymorphic, representing 63.3% of all the amplified loci. Polymorphism percentage ranged from 50 to 90% and an average number of polymorphic bands of 4.0 were observed. An average genetic diversity index was 0.61. Primer UBC860 and UBC825 generated the greatest diversity index with a value of 0.89 and 0.85 respectively. The smallest diversity identified by primer UBC808, with an index of 0.34. The genetic similarity among studied genotypes ranged from 0.52 to 0.98. The cluster analysis based on Jaccard?s similarity coefficient divided genotypes into 6 distinct clusters on a value of 0.74. The lowest genetic distance was found between ?Gronastiy? and ?AG1224? (0.52), ?Orange? and ?AG1224? (0.54), and ?Evgeniya? and ?AG1224? (0.55) accessions. The highest similarity of 0.98 was determined between ?Zafar? and ?Azerbaijan-94?, ?Khachmaz-1? and ?Azerbaijan-94?, ?Khachmaz-1? and ?Severyanka?, and ?Shakar? and ?Absheron-1? accessions.

The QTLs, Determination of Cocoon Shell Weight Trait in Mulberry Silkworm (Bombyx mori L.)

2009 ◽  
Vol 9 (1) ◽  
pp. 41-47 ◽  
Author(s):  
A.R. Bizhannia ◽  
S.Z. Mirhossein ◽  
B. Rabiee ◽  
M. Taeb
Keyword(s):  
Bombyx Mori ◽  
Shell Weight ◽  
Bombyx Mori L ◽  
Mulberry Silkworm ◽  
Weight Trait ◽  
Silkworm Bombyx Mori

scholarly journals Assessment of Genetic Diversity of an Endangered Species Fraxinus hupehensis Based on ISSR Markers

2019 ◽  
Vol 47 (4) ◽  
pp. 1308-1315
Author(s):  
Peng-Li ZHENG ◽  
Jian-Ru CHENG ◽  
Long-Qing CHEN ◽  
Ming-Qin ZHOU
Keyword(s):  
Genetic Diversity ◽  
Endangered Species ◽  
Diversity Index ◽  
Gene Diversity ◽  
Natural Populations ◽  
Population Level ◽  
Issr Markers ◽  
Group Method ◽  
Digital Object Identifier ◽  
Protection Measures

Investigation on the level and pattern of genetic diversity of 10 natural populations of the endangered species Fraxinus hupehensis using inter-simple sequence repeat (ISSR) markers was crucial for understanding the structure of the population and assessing the best genetic protection strategies. A total of 180 polymorphic bands with the polymorphic rate of 100.00% were amplified by 14 primers. The genetic diversity at population level (Percentage of polymorphic loci, PPL=64.06; Nei’s gene diversity index, h=0.1519; Shannon’s information index, I=0.2434) was lower than that at species level (PPL= 100.00%, h=0.1833, I=0.3041). Analysis of molecular variance (AMOVA) demonstrated the low level of the genetic variation occurred between the populations (16.05%). This also can be corroborated by the gene flow (Nm 2.424) and the coefficient of gene differentiation (Gst=0.1710) among populations. Cluster analysis based on the unweighted pair group method with arithmetic averages (UPGMA) revealed four groups for 10 populations according to Nei’s genetic identity and seven categories for the 196 individuals according to SM values. Furthermore, the endangered mechanism and genetic structure of F. hupehensis were discussed, and appropriate targeted protection measures were proposed based on these findings.   ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 4, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********

scholarly journals Genetic Variation of Safflower (Carthamus Tinctorius L.) and Related Species Revealed by ISSR Analysis

2014 ◽  
Vol 66 (1) ◽  
pp. 139-150 ◽  
Author(s):  
Hamed Bagmohammadi ◽  
Mohammadhadi Pahlevani ◽  
Asadollah Ahmadikhah ◽  
Seyed Esmaeil Razavi
Keyword(s):  
Cluster Analysis ◽  
Diversity Index ◽  
Gene Diversity ◽  
Carthamus Tinctorius ◽  
Inter Simple Sequence Repeat ◽  
Issr Markers ◽  
Genetic Distances ◽  
Group Method ◽  
Pair Group ◽  
Close Relationship

Abstract Genetic diversity of eight genotypes of Carthamus tinctorius L., two populations of C. oxyacanthus, and one population of C. lanatus was investigated using inter-simple sequence repeat (ISSR) markers. All samples were uniquely distinguished by 10 ISSR primers with 144 bands which generated 100% polymorphism. Furthermore, the ISSR markers could separate three safflower species properly, that highlights the effectiveness of this marker system for phylogenetic studies. The most and least informative primers were ISSR9 (PIC=0.367) and ISSR2 (PIC=0.254), and some primers were more efficient in detecting polymorphism in one species than for the others. Unweighed pair-group method with arithmetical averages (UPGMA) cluster analysis enabled construction of a dendrogram for estimating genetic distances among different populations. The result of cluster analysis suggested that cultivated and wild populations of C. oxyacanthus had close relationship with each other and far relationship with C. lanatus. The extreme genetic dissimilarity was observed between genotypes of C. tinctorius and C. lanatus populations. Based on the results, C. oxyacanthus could introduce favorable genes to cultivated safflower via inter-specific hybridization in breeding programs. Nei’s gene diversity index, Shannon’s index and percent of polymorphic loci showed that Isfahan ecotype of C. oxyacanthus had the highest variation at DNA level in relation to populations of other species. The ISSRs developed in this research along with those recently studied by other researchers will contribute to construct genetic map with a density sufficient for safflower molecular breeding.

Analysis of genetic relationship in mutant silkworm strains of Bombyx mori using inter simple sequence repeat (ISSR) markers

2008 ◽  
Vol 35 (5) ◽  
pp. 291-297 ◽  
Author(s):  
Dhanikachalam Velu ◽  
Kangayam M. Ponnuvel ◽  
Murugiah Muthulakshmi ◽  
Randhir K. Sinha ◽  
Syed M.H. Qadri
Keyword(s):  
Bombyx Mori ◽  
Genetic Relationship ◽  
Simple Sequence Repeat ◽  
Inter Simple Sequence Repeat ◽  
Issr Markers ◽  
Sequence Repeat ◽  
Simple Sequence

scholarly journals Stability and path analysis for yield and related traits in silkworm, (Bombyx mori L.) reared under stress conditions

Genetika ◽  
2016 ◽  
Vol 48 (1) ◽  
pp. 271-284
Author(s):  
N. Chandrakanth ◽  
S.M. Moorthy ◽  
M. Rekha ◽  
V. Sivaprasad
Keyword(s):  
Bombyx Mori ◽  
High Temperatures ◽  
Analysis Of Variance ◽  
Path Coefficient ◽  
Larval Weight ◽  
Stability Parameters ◽  
Shell Weight ◽  
Pupation Rate ◽  
Bombyx Mori L ◽  
Silkworm Bombyx Mori

The silkworm, Bombyx mori L. is a poikilothermic organism whose growth and development is adversely affected by high temperatures. Rearing of silkworm at high temperature conditions of tropical countries like India causes extensive crop loss by reducing cocoon yield. Breeding new silkworm breeds tolerant to high temperatures is the most effective and economical method to increase cocoon yield. Introduction of stable genotypes in such breeding programs and knowledge on the relationships between cocoon yield and other traits would be more advantageous in increasing cocoon yield at high temperatures. Therefore, in this study twenty silkworm genotypes were reared in five artificially simulated environments with different temperatures ranging from 25?C to 38?C. Based on coefficient of variation (%) values, the traits cocoon yield / 10,000 larvae by weight (CY) and cocoon weight showed maximum and minimal variation among the traits in all the five environments. Analysis of variance revealed a substantial genetic variability among the genotypes for most of the traits studied. The results of combined analysis of variance showed significant differences over traits indicating that the traits are influenced by genotype ? environment interactions. Stability analysis with respect to CY showed higher mean value compared to grand mean, regression coefficient equal to unity and less deviation from regression in ATR16, CSR17, BHR2, S-5 and D13 genotypes, suggesting that they are consistent with the CY over the different environments. Clustering based on the stability parameters resulted in separation of twenty silkworm genotypes into 5 clusters based on their ability to tolerate high temperatures. Correlation studies demonstrated positive and significant (P < 0.05) correlations between CY and other traits. Pupation rate was most positively associated with CY followed by larval weight, cocoon weight, cocoon shell weight and cocoon shell percent. Path coefficient analysis also revealed that the pupation rate had the maximum direct effect on CY followed by cocoon shell weight and larval weight. Cocoon shell percent and cocoon weight exhibited negative direct path effect on cocoon yield / 10,000 larvae by weight. Therefore, the selection based on pupation rate, larval weight and cocoon shell weight can be effective in improving cocoon yield in silkworm at different environments with varying temperature.

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