Morphological and molecular variability in some Iranian almond genotypes and related Prunus species and their potentials for rootstock breeding
In this study, in order to know the variability for a rootstock breeding program genetic diversity and relationships among 55 Iranian almond genotypes and seven related Prunus species were investigated. Morphological and molecular analyses were used. Principal component analysis showed that three components explained 67.6% of the total morphological variation for the first year and 68.06% for the second year of the study. Leaf traits were predominant in the first component and contributed most of the total variation. Leaf length and width, as well as, leaf area were highly correlated with each other and correlated to vigor. Also a negative correlation was found between leaf length/width ratio and vigor. Ward's method was used to construct cluster from morphological data which allocated individuals into their respective species. Out of 100 pre-screened RAPD primers, 16 with reproducible bands and maximum polymorphism were selected. Two-hundred and sixty bands were scored of which 250 of them were polymorphic. Average value of polymorphism per primer was 95.81% and maximum value for polymorphism (100%) was obtained from TIBMBA-14, TIBMBA-17, TIBMBB-05, TIBMBB-08, TIBMBD-09, and TIBMBD-10. On the other hand, the minimum value was obtained from TIBMBB-16 (86%). Primer TIBMBB-5 gave the maximum number of bands (25 fragments) and the minimum obtained from TIBMBE-18 (11 fragments). Genetic similarity based on Jaccard's coefficient ranged from 0.28 to 0.79 with an average of 0.53. Molecular analysis revealed a high degree of separation among samples regarding their geographical origin. Correlation between two approaches was low (R =−0.38). High molecular and morphological variability indicated that this collection includes rich and valuable plant materials for almond rootstock breeding.
Genome wide association study (GWAS) of early vigour and flowering time in canola (Brassica napus)
Canola is one of the most agronomically important members of the Brassicaceae family with an approximately 1 billion USD export value for the Australian agriculture industry. However, this crop requires more efficient plant breeding strategies to satisfy its market dynamics and problems resulted from its limited genetic diversity. Therefore, accurate identification of genomic regions (QTLs) controlling the genetic architecture of important traits (e.g. early vigour and flowering time) and the estimation of their effects are of crucial priorities for a sustainable plant breeding program in canola. In this study we have used genome wide association study (GWAS) to find statistically significant associations between early vigour and flowering time and more than 13,000 Illumina Infinium™ Single Nucleotide Polymorphisms (SNPs) in a canola germplasm. For days to 50% flowering, we found significant associations in genomic regions, particularly chromosomes A02 and A03, that seem to be associated in controlling the flowering time. We compared the results from three different methods for our analysis: 1) general linear model, 2) mixed model using kinship matrix (K), and 3) a unified Mixed Model that incorporates both K and population structure (Q). Consistent QTLs were located in similar chromosome regions in the three different methods across three trial locations. Similar methods were employed to assess QTLs for early vigour in the glasshouse and field. Potential epistatic interactions between genes controlling early vigour and flowering time were explored. The study will also identify SNP molecular markers for these traits for use in the Australian canola breeding industry.
T-DNA Insertion Lines with Altered Root System Architecture in Arabidopsis thaliana
Root system architecture of plants is a complicated phenotype that is pivotal to processes as fundamental as acquisition of water and nutrients, stress tolerance and anchorage in soil. This poster presents preliminary results of a search for genes that contribute to root system architecture in the model plant Arabidopsis thaliana. With the aid of microscopic observations, reverse and molecular genetics, we have identified genes functioning in different cellular pathways that contribute to Arabidopsis root system architecture. The study will expand our current understanding of how root systems grow and develop in plants, potentially facilitating the improvement of crop species.
Phenotypic and molecular variability and genetic structure of Iranian almond cultivars
In this study, we used 20 morphological traits (during two consecutive growing seasons) and 11 microsatellite markers to assess the morphological and molecular variability and structure of the almond (Prunus dulcis (Mill.) D.A. Webb). Seventy one promising Iranian genotypes and three foreign reference cultivars (Ferragnes, Supernova, and Touno) were evaluated in this study. Kernel/shell ratio, kernel width/thickness ratio, softness of shell, nut weight, and kernel thickness were highly variable. Strong positive and, occasionally, negative correlations were detected among nut and kernel traits. Morphological traits were categorized by principle-components analysis (PCA) into 6 components which explained 88.1 % of the total variation. On the basis of the first two PCA axes, the 2-dimensional PCA plot grouped the samples according to their phenotypic characteristics. The results from molecular analyses (including a Bayesian clustering approach and a molecular phylogenetic network) did not correspond to morphological groupings. In this paper we report, for the first time, morphological and molecular variability and genetic structure of Iranian almond germplasm. Our results showed that model-based cluster analysis (using Structure software) was very appropriate for study of genetic relationships among almond accessions and can be used for study of the genetic structure of Prunus germplasm as well.
Stable genetic and phenotypic correlations among early-vigour traits in field and glasshouse reveal opportunities for indirect selection in canola breeding
Background:
Higher grain yield is a primary objective for breeding programs of Brassica oilseed crops, and is known to be affected directly or indirectly by several growth-associated traits which can be measured in the glasshouse and field in early generations. Indirect genomic selection for such traits may ultimately help to increase the rate of genetic gain for grain yield.
Objective:
The objective was to determine if genomic estimated breeding values (GEBV) for early-vigour traits measured in the glasshouse were correlated with vigour and grain yield in the field. Correlated traits are useful to improve the accuracy of genomic selection, which means that indirect genomic selection in early generations of canola breeding may improve genetic gain in canola breeding.
Methods:
We measured vigour-related traits in the field and glasshouse in a population of doubled haploid lines in the Australian Brassica napus Homozygous Diversity Set, genotyped with 12,197 Infinium Illumina SNP markers. We measured area, biomass and shape of the 4th leaf in the glasshouse and field, and compared this to whole-plant traits such as normalized difference vegetation index (NDVI), biomass and grain yield. Phenotypes were adjusted for the fixed effects (spatial effects in the glasshouse and field) to get the BLUEs for genomic best linear unbiased prediction (GBLUP) analysis. Genetic parameters including heritabilities and genetic correlations between traits were estimated.
Results:
Early-vigour traits showed low to moderate narrow-sense heritabilities. Phenotypic means and GEBV of several traits in the glasshouse were positively correlated with similar traits (and also with biomass and NDVI) in the field. GEBVs for dry biomass and area of the 4th leaf (as a representative of a fully functional leaf during early vigour) were highly correlated across lines within experiments, and between glasshouse and field. These traits showed moderate to high genotypic correlations with biomass and NDVI in field trials at several locations. Leaf shape characteristics such as roundness and aspect ratio also showed consistent correlations with other vigour traits including NDVI. The petiole length of the 4th leaf showed a moderate negative correlation with grain yield for the field trials at Wagga Wagga in 2021 and 2022, but correlations between early vigour traits and grain yield were weak and inconsistent.
Conclusions:
High genetic correlations for early vigour traits occurred across the glasshouse and field, and seedling vigour-related traits were correlated with whole-plant vigour traits such as NDVI and biomass. Genomic regions that control seedling vigour-related traits such as petiole length and leaf shape can have potential pleiotropic roles for controlling other traits such as NDVI. However, early-vigour traits were less useful for predicting final grain yield, since grain yield is affected by other traits such as flowering date and ability to set seeds under stress. The accuracy of GEBV for vigour-related traits can also be improve with multivariate genomic analysis that includes glasshouse measures of seedling vigour. Our results suggest that breeding systems will benefit from early vigour evaluations during “speed breeding” (rapid single seed descent) in the glasshouse.
Genetic Diversity and Relationships among Some Iranian Cultivated Almond Genotypes and Related Wild Species Using RAPD Markers
Iran is worldwide one of the main growing regions for commercial and wild almonds due to its suitable climatic conditions. In this study, we characterized using RAPDs the genetic diversity and relationships between 62 almond genotypes, including eight related species (P. dulcis, P. scoparia, P. arabica, P. eburnea, P. erioclada, P. lycioides, P. orientalis and P. communis). Sixteen RAPD primers (TIBMOLBIOL Co., Germany) produced 260 bands from which 250 were polymorphic (96.15%). Total resolving power (Rp) was 121.83, ranging from a minimum of 4.25 for TIBMBB-16 to a maximum of 11.64 for TIBMBD-05. Jaccard similarity coefficient was calculated and was used to construct an UPGMA dendro-gram. Similarity values among the studied genotypes ranged between 0.28 and 0.79 with an average of 0.53. Cluster analysis and principle coordinate analysis (PCoA), partially discriminated the genotypes studied regarding their geographical origin. At the similarity of 0.52 in the dendrogram, the genotypes were divided into four sub-clusters. Our results indicated a wide genetic diversity at molecular level for the existing almond germplasm in Iran.
Ferulago angulata and Tetrataenium lasiopetalum: Essential oils composition and antibacterial activity of the oils and extracts
In the present research, the chemical composition of the essential oils from Ferulago angulata and Tetrataenium lasiopetalum were analyzed by the gas chromatography-mass spectrometry (GC-MS). The antibacterial activity of the extracts and essential oils of both species was also evaluated against Staphylococcus aureus and Enterococcus faecalis (Gram-positive bacteria) and Escherichia coli and Pseudomonas aeruginosa (Gram-negative bacteria), using agar disk diffusion and micro-dilution methods. Our results showed that essential oil from F. angulata was a rich source of cis-β-ocimene, α-pinene and α-phellandrene and can be used in industries such as pharmaceutical, cosmetic and food. Additionally, T. lasiopetalum essential oil had high percentage of camphene, germacrene-D, and 1,8-cineole. Gram positive bacteria were more susceptible than Gram-negative bacteria to all oils and extracts. The results of our study showed that in both species, especially T. lasiopetalum, the extract and essential oils exhibited reliable inhibitory activity against both Gram-positive and Gram-negative bacteria and have the potential to be considered as natural alternatives for food preservatives.
An Investigation of Genetic Diversity among Some Almond Genotypes and Species by Morphological Traits
Almond [Prunus dulcis (Mill.) D.A. Webb] is one of the species of genus Prunus and subgenus Amygdalus (Rosaceae, subfamily Prunoideae). It is grown commercially worldwide. Iran is one of the main growing areas for commercial and wild almonds due to its suitable climatic conditions. Wild almond species are known to be tolerant to harsh environmental conditions such as drought. They also can be used as rootstock or can be employed in improvement programs. In this study, 62 genotypes including eight different species were evaluated by measuring 15 morphological traits. Correlation coefficient showed significant correlation among length of trunk, diameter of trunk, tree vigor, foliage density, length of main branches, thickness of one year old shoot, leaf length and width, leaf area and the leaf length/width ratio. Principal component analysis showed that length of main branches, ramification, length of one year old shoot, leaf length and width, leaf area and the length/width ratio of leaf had highest loading in the first component that accounted for 35.6% of total variation (67.8%). Cluster analysis divided genotypes into two main groups and wild species were separated at distance of 5 from the others.