Assessing the effectiveness of different molecular markers is essential for identification of appropriate ones for crop improvement and conservation, hence, inter-simple sequence repeat (ISSR) and start codon targeted (SCoT) markers were used for this study. Sixty-six accessions with different genomes obtained from International Transit Center, Belgium, were used for DNA extraction, amplification with ISSR and SCoT markers and agarose gel electrophoresis. The reproducible bands were scored for analyses. We identified high allelic richness of 299 (ISSR) and 326 (SCoT). Polymorphic information contents (ISSR: 0.9225; SCoT: 0.9421) were high but SCoT exhibited higher level of informativeness. The two markers demonstrated high percentage polymorphic loci (ISSR: 91.21–100%; SCoT: 96.97–100%). Other genetic indicators including effective number of alleles, Nei’s genetic diversity, and Shannon information index were higher in SCoT and further elucidated the usefulness of the markers. Intraspecific genetic diversity, interspecific genetic diversity, coefficient of gene differentiation and level of gene flow revealed extensive gene flow and larger variability within the accessions. Both ISSR and SCoT grouped the accessions via dendrogram, biplot and structure analyses. Though the two marker systems varied in their informativeness, they demonstrated high effectiveness in resolving genetic diversity (GD) of the different accessions, with higher efficiency in SCoT markers. Due to higher GD indices exhibited by SCoT, AS is the most genetically endowed one. Our study showed that SCoT markers are more informative than ISSR for GD exploration, assessment and cluster resolution of Musa species, thereby revealing the potential of SCoT markers for improved breeding and conservation.
Within Enugu and Anambra States, Nigeria, identification of fishes has been based on morphological traits and do not account for existing biodiversity. For DNA barcoding, assessment of biodiversity, conservation and fishery management, 44 fish sampled from Enugu and Anambra States were isolated, amplified and sequenced with mitochondrial cytochrome oxidase subunit I (COI). Twenty groups clustering at 100% bootstrap value including monophyletic ones were identified. The phylogenetic diversity (PD) ranged from 0.0397 (Synodontis obesus) to 0.2147 (Parachanna obscura). The highest percentage of genetic distance based on Kimura 2-parameter was 37.00 ± 0.0400. Intergeneric distances ranged from 15.8000 to 37.0000%. Congeneric distances were 6.9000 ± 0.0140–28.1000 ± 0.0380, withSynodontisas the existing synonymous genus. Confamilial distances in percentage were 16.0000 ± 0.0140 and 25.7000 ± 0.0300. Forty-two haplotypes and haplotype diversity of 0.9990 ± 0.0003 were detected. Nucleotide diversity was 0.7372, while Fu and Li’s D* test statistic was 2.1743 (P < 0.02). Tajima’s D was 0.2424 (P > 0.10) and nucleotide frequencies were C (17.70%), T (29.40%), A (24.82%), G (18.04%) and A + T (54.22%). Transitional mutations were more than transversions. Twenty species (99–100%) were identified with the e-value, maximum coverage and bit-score of 1e−43, 99–100 and 185–1194, respectively. Seventeen genera and 12 families were found and Clariidae (n = 14) was the most dominant among other families. The fish species resolution, diversity assessment and phylogenetic relationships were successfully obtained with the COI marker. Clariidae had the highest number of genera and families. Phylogenetic diversity analysis identifiedParachanna obscuraas the most evolutionarily divergent one. This study will contribute to fishery management, and conservation of freshwater fishes in Enugu and Anambra States, Nigeria.
Sixty-six accessions ofMusagenus with different genomic groups that consisted of wild relatives and cultivated lines were obtained from the International Transit Center, Belgium, for DNA extraction using Cetyl trimethylammonium bromide method, followed by amplification with Conserved DNA-derived Polymorphism (CDDP) markers for genetic diversity and population assessment. A total of 421 alleles with major allele frequency of 2.051 were detected from the reproducible markers. High genetic diversity (GD, 11.093) and polymorphic information content (0.918) were revealed. The number of polymorphic loci and percentage of polymorphic loci ranged from 59 to 66 and 89.34 to 100, respectively. Using the potential genetic indicators including effective number of alleles, Nei’s genetic diversity, and Shannon’s information index, the AS genomic group was identified to have the highest GD, while the AAA accessions had the lowest GD indices. The GD parameters identified in the accessions were ranked as AS > AAB > AAAA > AA > ABB > wild diploidy > BB > AB > AAA from high to low based on polymorphic loci of the markers. Total intraspecific GD, interspecific GD, and estimate gene flow identified were 0.433, 0.404, and 7.113, respectively. The coefficient of gene differentiation of 0.066 was obtained, indicating 6.57% among the population and 93.43% within the population. Dendrogram analysis produced nine major groups with subgroups at similarity index of 0.814. These CDDP functional gene-based markers were informative and very efficient in resolving GD, and population indices among the banana and plantain accessions of different genomes. The identified CDDP markers might serve as potential tools for selecting suitable training populations for breeding and conservation ofMusaspecies.
1 December 2006 in Plant Genetic Resources: Characterization and Utilization
Amplified fragment length polymorphism (AFLP) markers were employed to assess intraspecific variability in water yam (Dioscorea alataL.). Fifty-three accessions of diverse geographic origins in West and Central Africa (Benin, Côte d'Ivoire, Ghana, Nigeria and Chad) and Puerto Rico were analysed using three AFLP primer combinations. Of the 342 amplification products generated, a mean of 53.4% were polymorphic. Genetic similarity coefficients ranged from 0.29 to 0.95. The accessions could be clustered into three major genetic groups with one outlier. Each group was a mixture of accessions of different geographical origin indicating that geography has not played a major role in the differentiation of the species. A few accessions clustered very tightly suggesting that there may be duplicate accessions in the collection. The wide genetic variation observed constitutes a good basis for genetic improvement of yam.
Bananas and plantains, belonging to the Musa genus, are important food crops that sustain the livelihoods of countless smallholder farmers globally. However, their production is hindered by various challenges, including abiotic and biotic stresses, climate change, and poor access to clean planting materials, which negatively impact their yields. Addressing these constraints is essential for improving production and ensuring food security. This study investigated the influence of triploid genome background and exogenous growth regulators on the regeneration of Musa cultivars [Gros Michel (AAA genome), Obino l’Ewai and Silk (AAB genome), and Poteau Naine (ABB genome)]. Shoot tip explants of the AAA, AAB, and ABB triploid genomes were cultured in Murashige and Skoog (MS) media supplemented with varying 6-benzylaminopurine (BAP) and indole-3-butyric acid (IBA), indole-3-acetic acid (IAA), or naphthaleneacetic acid (NAA) hormones. Shoot induction was successfully achieved within 21.50 ± 2.00 days, with AAA exhibiting the highest shoot induction frequencies ranging from 30.00 ± 1.57% to 100% and shoot numbers per explant ranging from 3.00 ± 0.50 to 8.80 ± 0.80, followed by the ABB genome ranging from 20.00 ± 3.45% to 100% and from 2.00 ± 0.55 to 5.60 ± 0.50 shoots, and the AAB genome ranging from 17.50 ± 5.01% to 100% and from 2.00 ± 0.04 to 6.60 ± 0.25 shoots, respectively, in media amended with 1.2 to 6.0 mg.L−1 BAP and 0.1 mg.L−1 IAA. The highest rooting rate of 100% was recorded in all three genomes in media containing 1.4 mg.L−1 IBA and 0.5 mg.L−1 IAA, with the AAA genome producing the maximum number of 14.8 roots per explant. The results indicate the positive influence of the AAA genome background on in vitro regeneration and its potential utilization for genomic editing transformation protocols
The high quantity of polyphenols and polysaccharides present in the tissues of Musa spp. often leads to the degradation of nucleic acids, which is why all previously established methods resulted in lesser yield and poor quality of RNA. In this study, we present a modified SDS-based RNA extraction method to improve the quality and yield of RNA from different tissues of Musa spp. for downstream applications. The modification of RNA extraction buffer, SDS, heat incubation, and use of LiCl resulted in high-intensity RNA bands and increased RNA yield. The clear ribosomal RNA bands ensured the high quality of intact RNA without genomic DNA contamination, along with A260/A280 and A260/A230 ratios ranging from 1.83 to 2.25, which indicated the high quality of RNA across different banana varieties and tissue types. This method was found to be very effective when RNA was extracted from drought-stressed plants yielding 2.92 to 6.30 µg/100 mg fresh weight with high RNA integrity and quality (RNA IQ) 7.8–9.9 from the different groups of Musa tissues. Additionally, the RNA was successfully applied in PCR and quantitative real-time PCR (qRT-PCR), confirming downstream application in gene expression analysis. This method is a reliable and efficient technique for RNA extraction methods like Trizol, NucleoSpin, RNeasy, and CTAB procedures reported so far.