ABSTRACT
Background and Objective: Plantain (Musa paradisiaca L) remains one of themost important staple food crop and perhaps, one of the oldest cultivated fruit tree crop in the humid tropics of Africa, Central Asia, South America and the West Indies.Fourteen (14) elite plantain cultivars were evaluated for genetic diversity using agro-morphological yield related attributes and simple sequence repeat (SSR) markers. Materials and Methods: Six (6) microsatellite markers that showed distinct fragments varying from 50 bp to 3.0 Kbp in size of polymorphic bands were selected and used for molecular characterization and fingerprinting, while agro-morphological (yield杛elated) attributes assessed included bunch weight, number of hands/bunch, number of fingers/hands, number of fingers/bunch, harvest interval, length of plant cycle, pulp hardness and pulp to skin weight ratio of the elite plantain cultivars. Results: The total number of amplified bands (TNB), mean percentage polymorphism (%P), mean polymorphic information content (PIC), average marker index (MI) and mean gene diversity for the SSR assay were 59, 70.24%, 0.79, 3.74 and 0.832 respectively. Results of agro-morphological fingerprint study revealed a significant variations in terms of the bunch weight, number of finger per hands/bunch, number of fingers per hand, number of fingers /bunch, harvest interval, length of crop cycle, pulp hardness and pulp/wt. ratio all showed significant variations among the cultivars. The distribution of the elite cultivars along with the principal components showed cluster pattern of distribution within the study location. Principal component analysis revealed four principal components contributing 99.91% to the observed morphological variations while analysis of molecular variance revealed 96.00% contributed by molecular characteristics to observed variations. The yield displayed revealed significant contributions of bunch weight, fingers/hand and fingers/bunch as the main indices for plantain yield. The dendrograms for both morphological and molecular characteristics delineated the cultivars into four distinct cluster groups and subgroups each varying in genetic distance. Conclusion: These good cultivars can be exploited for the improvement of low yielding cultivars in other region to increase and improve plantain yield, promote food security and income generation especially under the present economic realities where food security is threatened by the global food crises and declining crop productivity.
ABSTRACT
Strain is the fundamental unit in microbial taxonomy. The functional diversity among strains has great influence on host phenotypes. With the development of microbiome research, knowing the composition and functional capacities of complex microbial communities at the strain level has become increasingly valuable in scientific research and clinical applications. This review introduces the principles of bioinformatics algorithms for strain analysis based on metagenomic data, the applications in microbiome research and directions of future development.
Subject(s)
Algorithms , Computational Biology , Metagenome , Metagenomics , Microbiota/geneticsABSTRACT
OBJECTIVE:To provide reference for imipenem-resistant Pseudomonas aeruginosa infection control. METHODS:114 patients infected with imipenem-resistant P. aeruginosa were selected from 3 tertiary hospitals in Zhoushan during Feb. 2013 to Feb. 2014. 114 strains of P. aeruginosa were isolated from clinical specimens,and drug resistance characteristics and carbapene-mase-producing gene diversity were analyzed. 101 inpatients with imipenem-resistant P. aeruginosa infection were included in con-trol group;univariate and multivariate Logistic regression analysis were adopted to explore the risk factors of imipenem-resistant P. aeruginosa infection. RESULTS:114 strains were sensitive to polymyxin B,and had different levels of resistance to other 9 kinds of antibiotics. Carbapenemase-producing gene were mainly IMP and VIM type gene. Long-term hospitalization,mechanical ventila-tion,used imipenem and early combined use of antibiotics were risk factors of imipenem-resistant P. aeruginosa infection. CON-CLUSIONS:In Zhoushan area,imipenem-resistant P. aeruginosa shows serious drug resistance. To avoid long-term hospitalization and early combined use of antibiotics can reduce imipenem-resistant P. aeruginosa infection.
ABSTRACT
Deforestation and exploitation has led to the fragmentation of habitats and scattering of populations of the economically important eri silkworm, Samia cynthia ricini, in north-east India. Genetic analysis of 15 eri populations, using ISSR markers, showed 98 percent inter-population, and 23 percent to 58 percent intra-population polymorphism. Nei's genetic distance between populations increased significantly with altitude (R² = 0.71) and geographic distance (R² = 0.78). On the dendrogram, the lower and upper Assam populations were clustered separately, with intermediate grouping of those from Barpathar and Chuchuyimlang, consistent with geographical distribution. The Nei's gene diversity index was 0.350 in total populations and 0.121 in subpopulations. The genetic differentiation estimate (Gst) was 0.276 among scattered populations. Neutrality tests showed deviation of 118 loci from Hardy-Weinberg equilibrium. The number of loci that deviated from neutrality increased with altitude (R² = 0.63). Test of linkage disequilibrium showed greater contribution of variance among eri subpopulations to total variance. D'2IS exceeded D'2ST, showed significant contribution of random genetic drift to the increase in variance of disequilibrium in subpopulations. In the Lakhimpur population, the peripheral part was separated from the core by a genetic distance of 0.260. Patchy habitats promoted low genetic variability, high linkage disequilibrium and colonization by new subpopulations. Increased gene flow and habitat-area expansion are required to maintain higher genetic variability and conservation of the original S. c. ricini gene pool.
Subject(s)
Animals , Bombyx/genetics , Genetic Variation , Genetics, Population , Genetic Markers , India , PhenotypeABSTRACT
Objective: The genetic diversity of Artemisia annua germplasmic resources in natural populations of China was analyzed by SRAP marker. Methods: Taking 60 germplasm of A. annua version in main distribution areas of natural population in China as testing materials, the relative parameters were calculated by Popgene version 1.31 and Treeconw software. The systematic diagram of genetic relationship was made up by Treeconw software and clustered by UPGMA method. Results: The 232 DNA bands were amplified with 24 pairs of SRAP primer combinations, and the percentage of polymorphic bands (PPB) was 81.47%. At species level: Nei's gene diversity (H) was 0.190 5 using SRAP marker. Shannon's information index (I) was 0.300 0 by SRAPs; Among the four areas with higher level of artemisinin: PPB were 50.00%-61.21%, the average was 55.82%. He were 0.155 7-0.179 3 by SRAP marker. I were 0.237 9-0.276 6 by SRAP maker; Genetic distance were 0.643 2-0.872 7, the average was 0.754 7. Conclusion: SRAP marker is an efficient method in revealing the abundant genetic diversity of wild A. annua in China, which provides the material basis for promising germplasm of further breeding.
ABSTRACT
The evolutionary origin of murine line based on a phylogenetic tree made on sequence data of ∝-and β-hemoglobin chains, followed by the diversity spectrum of hemoglobin genes in two wild species of murine rodents: Rattus rattus rufescens (house rat) and Bandicota indica (bandicoot rat) has been reported. Each house rat contains six hemoglobin types involving two ∝-and three β-chains, which suggests a probable gene duplication at the ∝ chain locus and a gene triplication at the β-chain locus. Each bandicoot rat contains one ∝-and two β-chains suggesting a probable gene duplication at the β-chain locus. Peptide pattern analysis of the polypeptide chains of these murine hemoglobins further indicates that intraspecies differences among duplicated chains of the same kind are less than interspecies differences among corresponding ∝- and β-chains.