Genetic diversity analysis in wheat cultivars using SCoT and ISSR markers, chloroplast DNA barcoding and grain SEM.

BACKGROUND: Wheat is a major cereal that can narrow the gap between the increasing human population and food production. In this connection, assessing genetic diversity and conserving wheat genetic resources for future exploitation is very important for breeding new cultivars that may withstand the expected climate change. The current study evaluates the genetic diversity in selected wheat cultivars using ISSR and SCoT markers, the rbcL and matK chloroplast DNA barcoding, and grain surface sculpture characteristics. We anticipate that these objectives may prioritize using the selected cultivars to improve wheat production. The selected collection of cultivars may lead to the identification of cultivars adapted to a broad spectrum of climatic environments. RESULTS: Multivariate clustering analyses of the ISSR and SCoT DNA fingerprinting polymorphism grouped three Egyptian cultivars with cultivar El-Nielain from Sudan, cultivar Aguilal from Morocco, and cultivar Attila from Mexico. In the other group, cultivar Cook from Australia and cultivar Chinese-166 were differentiated from four other cultivars: cultivar Cham-10 from Syria, cultivar Seri-82 from Mexico, cultivar Inqalab-91 from Pakistan, and cultivar Sonalika from India. In the PCA analysis, the Egyptian cultivars were distinct from the other studied cultivars. The rbcL and matK sequence variation analysis indicated similarities between Egyptian cultivars and cultivar Cham-10 from Syria and cultivar Inqalab-91 from Pakistan, whereas cultivar Attila from Mexico was distinguished from all other cultivars. Combining the data of ISSR and SCoT with the rbcL and matK results retained the close resemblance among the two Egyptian cultivars EGY1: Gemmeiza-9 and EGY3: Sakha-93, and the Moroccan cultivar Aguilal, and the Sudanese cultivar El-Nielain and between Seri-82, Inqalab-91, and Sonalika cultivars. The analysis of all data distinguished cultivar Cham-10 from Syria from all other cultivars, and the analysis of grain traits indicated a close resemblance between cv. Cham-10 from and the two Egyptian cultivars Gemmeiza-9 and Sakha-93. CONCLUSIONS: The analysis of rbcL and matK chloroplast DNA barcoding agrees with the ISSR and the SCoT markers in supporting the close resemblance between the Egyptian cultivars, particularly Gemmeiza-9 and Sakha-93. The ISSR and SCoT data analyses significantly expressed high differentiation levels among the examined cultivars. Cultivars with closer resemblance may be recommended for breeding new wheat cultivars adapted to various climatic environments.

Molecular Phylogeny of Trifolium L. Section Trifolium with Reference to Chromosome Number and Subsections Delimitation.

The genus Trifolium is one of the largest genera of the legume family Fabaceae with ca. 255 species. The genus is divided into eight sections; the section Trifolium is a major section of the genus, comprising 73 species mainly distributed in the Mediterranean region. We used nuclear ribosomal DNA internal transcribed spacer (ITS) and morphological variation to reconsider the delimitation and phylogenetic relationships of species in the section Trifolium with reference to chromosomal variations. Bayesian analysis of ITS data delimited the species as three clades based on the analysis of ITS sequence and informative indels in combination with morphological variation. The phylogeny of the species by different analyses methods does not support their current delimitation in 17 subsections. The basic chromosome number x = 8 is the number for the genus Trifolium, from which x = 7, 6 and 5 were derived through successive aneuploidy events. With reference to the distribution of these numbers in the species of the section Trifolium, species in clade III and clade II are more evolved than species in clade I.

Investigating the Phenotypic Plasticity of the Invasive Weed Trianthema portulacastrum L.

Phenotypic plasticity is frequently highlighted as a key factor in plant invasiveness, as it enables invasive species to adapt to diverse, complicated habitats. Trianthema portulacastrum is one of the most common aggressive species that threaten different crops around the world. Phenotypic plasticity in T. portulacastrum was investigated by comparing variation in germination, vegetative macromorphology, photosynthetic pigments, stomatal complexes, and seed micromorphological traits of 35 samples collected from 35 different localities. One-way cluster analysis and principal component analysis (PCA) were used to classify samples into homogeneous groups based on the measured traits. Pairwise statistical comparisons were conducted between the three resulting groups. The phenotypic plasticity index (PI) was calculated and compared among different groups of characters. Results showed that photosynthetic pigments and macromorphological characteristics had the highest PI, followed by seed micromorphology, and then stomatal complex traits, while germination parameters showed the lowest PI. We propose that soil moisture, salinity, and temperature are the most determinative and explanative variables of the variation between the three classified groups. We strongly believe that the phenotypic plasticity of T. portulacastrum will support species abundance and spread even under expected changes in climatic conditions, in contrast to the vulnerable traditional crops.

Taxonomic Revisiting and Phylogenetic Placement of Two Endangered Plant Species: Silene leucophylla Boiss. and Silene schimperiana Boiss. (Caryophyllaceae).

The genus Silene L. is one of the largest genera in Caryophyllaceae, and is distributed in the Northern Hemisphere and South America. The endemic species Silene leucophylla and the near-endemic S. schimperiana are native to the Sinai Peninsula, Egypt. They have reduced population size and are endangered on national and international scales. These two species have typically been disregarded in most studies of the genus Silene. This research integrates the Scanning Electron Microscope (SEM), species micromorphology, and the phylogenetic analysis of four DNA markers: ITS, matK, rbcL and psb-A/trn-H. Trichomes were observed on the stem of Silene leucophylla, while the S. schimperiana has a glabrous stem. Irregular epicuticle platelets with sinuate margin were found in S. schimperiana. Oblong, bone-shaped, and irregularly arranged epidermal cells were present on the leaf of S. leucophylla, while Silene schimperiana leaf has "tetra-, penta-, hexa-, and polygonal" epidermal cells. Silene leucophylla and S. schimperiana have amphistomatic stomata. The Bayesian phylogenetic analysis of each marker individually or in combination represented the first phylogenetic study to reveal the generic and sectional classification of S. leucophylla and S. schimperiana. Two Silene complexes are proposed based on morphological and phylogenetic data. The Leucophylla complex was allied to section Siphonomorpha and the Schimperiana complex was related to section Sclerocalycinae. However, these two complexes need further investigation and more exhaustive sampling to infer their complex phylogenetic relationships.