Molecular genetic diversity of seaweeds morphologically related to Ulva rigida at three sites along the French Atlantic coast

Foliose species of the genus Ulva are notoriously difficult to identify due to their variable morphological characteristics and high phenotypic plasticity. We reassessed the taxonomic status of several distromatic foliose Ulva spp., morphologically related to Ulva rigida, using DNA barcoding with the chloroplastic tufA and rbcL (for a subset of taxa) genes for 339 selected attached Ulva specimens collected from three intertidal rocky sites. Two of the collection sites were in Brittany and one site was in Vendée, along the Atlantic coast of France. Molecular analyses included several museum specimens and the holotype of Ulva armoricana Dion, Reviers & Coat. We identified five different tufA haplotypes using a combination of phylogenetic analysis, with the support of several recently sequenced holotypes and lectotypes, and a species delimitation method based on hierarchical clustering. Four haplotypes were supported by validly named species: Ulva australis Areschoug, Ulva fenestrata Postels & Ruprecht, Ulva lacinulata (Kützing) Wittrock and U. rigida C. Agardh. The later was additionally investigated using rbcL. The fifth haplotype represented exact sequence matches to an unnamed species from European Atlantic coasts. Our results support: (1) the synonymy of both U. rigida sensu Bliding non C. Agardh and U. armoricana with U. lacinulata. This finding is based on current genetic analysis of tufA from the U. armoricana holotype and recent molecular characterization of the lectotype of U. laetevirens, which is synonymous to U. australis, (2) the presence of U. australis as a misidentified introduced species in Brittany, and (3) the presence of U. fenestrata and U. rigida in southern Brittany. The taxonomic history of each species is discussed, highlighting issues within distromatic foliose taxa of the genus Ulva and the need to genetically characterize all its available type specimens.

Molecular Dissection for Boll Shedding in Upland Cotton Using Microsatellites

DNA markers application in marker-assisted breeding of cotton is handicapped due to low genetic diversity in cotton germplasm. The present study was designed to identify DNA markers, predominately simple sequence repeats (SSRs), associated with tolerance/resistance to heat stress as a consequence of boll shedding. To find out the genetic diversity a total of 24 cotton genotypes and 50 SSR primers were used. Total 288 alleles were produced with an average of 5.7 alleles per primer. Bootstrap cluster analysis used to generate a dendrogram that cluster the 24 accessions into two main clusters. Eleven out of 24 genotypes fall in a single cluster. Phenotypically H-4074 gives more diversity, while genotypically H-4074 sheared the same genetic background as H-4070, H-4091 and H-4090. Low genetic diversity was observed among both genotypic and phenotypic as maximum varieties fall in single group. This study helps for selecting diverse accessions with multiple phenotypic traits, which were drought to boll shedding. It suggests further elaborating the molecular genetic diversity by using new SSR marker to improve the yield of cotton cultivars. These preliminary results set the stage for initiating in depth marker-trait association studies, which will be instrumental for initiating marker-assisted breeding in cotton.

Assessment of Morphological and Molecular Genetic Diversity in Pigeonpea [Cajanus cajan (L.) Millspaugh]

Background: The estimation of genetic diversity in pigeonpea is crucial for desiging breeding programmes and germplasm conservation. Morphological studies alone do not provide sufficient information to understand genetic diversity. Molecular analysis using SSRs can provide additional information on genetic diversity that can be used for selection of diverse parents. Methods: The experimental material for present study consisted of 50 diverse genotypes of pigeonpea. The fifty genotypes were planted in Randomized Complete Block Design consisted of three replications during the kharif 2020-21. The estimation of morphological genetic diversity was done by Mahalanobis D2 statistics. The molecular genetic diversity analysis was done by using 30 molecular markers in same genotypes. Result: The assessment of morphological diversity revealed that the fifty pigeonpea genotypes were grouped into four different clusters with cluster I as the largest cluster (33 genotypes). The molecular markers differentiated the 50 genotypes in five major clusters with cluster II as the largest cluster (24 genotypes). The results of present study suggested that morphological and molecular diversity in pigeonpea is different. On the basis of genetic distance, the genotypes RVSA 2014-1 and PA 406 were found most genetically distant and may be used in hybridization programme to create diverse progenies.

Molecular genetic diversity of some rabbit breeds based on mitochondrial 16S rRNA sequences

<p>The present study was performed to assess the genetic variations among six rabbit breeds in Egypt based on mitochondrial 16S rRNA sequences. The length of partial mitochondrial 16S rRNA in the six rabbit breeds ranged from 546 bp to 558 bp. The sequenced regions were submitted to GenBank/NCBI under accession numbers (MW052052 - MW052057). The average content of A+T was 57% in all breeds. Among breeds, the percentages of genetic distance values were ranged from 0.000 to 0.004. The highest P-distance (0.004) was found between the New Zealand White breed and all other breeds. The results support the suitability of mitochondrial 16S rRNA for genetic diversity analysis of rabbit breeds and the applicability for future research on genetic relationships and the phylogeny of rabbit breeds.</p>

Analysis of Morphological and Molecular Genetic Diversity of Salicornia Iranica Akhani Wildlife Populations around Urmia Lake, Iran

Salicornia is a halophyte plant capable of being irrigated with seawater, which can be used as an alternative food. Given this, it is necessary to study the potentials of this plant's morphological diversity in the natural environment. In this study, 33 wild populations of Salicornia were collected from different geographical areas around Urmia Lake during the flowering stage, and some morphological traits and 25 ISSR loci of the plant were measured. Based on morphological traits and the cluster analysis, Salicornia populations were divided into four groups. Overall, the high percentage of polymorphic gene loci (65.69%), the average number of effective alleles per gene locus (1.63), and the Shannon data index (0.540) indicate that ISSR markers can be used in Identify genetic diversity to be used. Molecular data cluster analysis divided the studied populations into two main groups, which included 12.12% and 87.88% of the populations, respectively. Based on the effective analysis of the population's genetic structure and the precise classification of individuals into suitable sub-populations, the value of K = 2 was calculated. The research findings indicated that markers UBC823, B, A7, and K, and with the Shannon index, effective allele, and large heterozygosity values are markers with the highest effectiveness compared to other markers utilized, and they are used better than other compounds in genetic distance. The findings of this study will aid in parental selection studies for breeding programs of salicornia in future.

Molecular Genetic Diversity and Population Structure in Ethiopian Chickpea Germplasm Accessions

Chickpea (Cicer arietinum L.) is a cheap source of protein and rich in minerals for people living in developing countries. In order to assess the existing molecular genetic diversity and determine population structures in selected Ethiopian chickpea germplasm accessions (118), a set of 46 simple sequence repeat (SSR) markers equally distributed on the chickpea genome were genotyped. A total of 572 alleles were detected from 46 SSR markers, and the number of alleles per locus varied from 2 (ICCM0289) to 28 (TA22). The average number of alleles per locus, polymorphism information content, and expected heterozygosity were 12, 0.684, and 0.699, respectively. Phylogenetic analysis grouped the 118 chickpea genotypes from diverse sources into three evolutionary and/or biological groups (improved desi, improved kabuli, and landraces). The population structure analysis revealed six sub-populations from 118 chickpea genotypes studied. AMOVA revealed that 57%, 29%, and 14% of the total genetic variations were observed among individuals, within populations, and among populations. The insights into the genetic diversity at molecular levels in the Ethiopian germplasm lines can be used for designing conservation strategies as well as the diverse germplasm lines identified in this study can be used for trait dissection and trait improvement.