Iranian Journal of Genetics and Plant Breeding
Volume:5 Issue: 2, Oct 2016

RNAi mechanism plays a major role in silencing the expression of target genes by siRNAs. In the current study, in silico properties of 30 genes in omega-2 gliadin and 266 nt and 326 nt mutations were investigated before and after cloning in an expression vector. Specific primers were designed for 30 genes with spacer regions of 75 nt and 178 nt (for gene invert repeats). The frequency of siRNA site and nucleotide mutations A/U to G/C were identified for target mRNA using in silico analysis. The results showed that invert repeat sequences consisting of spacer region of 178 nt had a high efficiency for target gene without nucleotide mismatches from A/U to G/C. Spacer regions were designed with long fragments for RNAi cassette instead of intron sequences. Paying enough attention to observe the location of mismatch nucleotides in siRNA and length spacer region before and after cloning reduced the deletion time of intron. At the same time, removal of epitopes in wheat dependent exercise-induced anaphylaxis (WDEIA) and celiac disease could be considered as advantages of the applied method compared to ligation in the bacterial vector.

Phenetic analysis of morphological characters in different species of Onobrychis Miller sect. Hymenobrychis DC. (Fabaceae), classified them in two main groups based on corolla features. To determine the phylogenetic relationships among the 13 species, chloroplast DNA sequences were used. Analysis of these data resulted in a well-resolved and well-supported phylogeny. Phylogenies generated by maximum likelihood show monophyly of O. sect. Hymenobrychis and the division of the section into two major clades. The first branching clade was formed by all the species of the section with large flowers, a yellowish corolla with or without venation and some species having a larger chromosome number (x=8 vs x=7). The second major clade includes the remaining species studied, all of which have small flowers, a yellowish corolla with or without venation or purple maculae and the common number of chromosomes (x=7). The compliance of the molecular, morphological and cytogenetic data indicates that x=8 is ancestral in the section and x=7 are derived through an aneuploid loss of a chromosome. The resulting phylogeny suggests the Zagros area as an origin of evolution in the sect. Hymenobrychis, followed by a radiation to the Alborz area in Iran.

The objective of this study was to estimate heritability, heterosis, and genetic parameters involved in the control of forage yield and quality in kenaf populations, using analysis of generation means. Two crosses were used; Cuba 2032×Accession 75-71 and IX51×Everglade 41. Experimental material comprised of P1 and P2, their F1 and F2 and BC1P1 and BC1P2 generations. The effects of generations were significant for all traits in both crosses. Results revealed that both additive and non-additive effects were important for the inheritance of the traits in both crosses. The additive gene effects had a higher contribution than dominance gene effects, for most of the traits in cross 1, while dominance gene effects had a greater contribution than additive gene effects, for most of the traits in cross 2. Broad-sense heritability was high for the majority of traits in two crosses, while narrow-sense heritability was higher in cross 1 than in cross 2 for all traits. In cross 2, heterosis estimates were higher than those of cross 1 for most of the traits. Thus, selecting the segregating generations would lead to a significant improvement for forage yield.

Cornelian cherry is one of the most important small fruits in Arasbaran region, with wide applications in medicines and food products. In this study, the relationship among 28 quantitative and qualitative traits related to fruit, leaf, tree, and flower of 20 cornelian cherry genotypes was evaluated. Significant positive as well as negative correlations were found among some important quantitative and qualitative traits. Multivariate analysis method such as factor analysis was used to assign the number of main factors. It showed that the characteristics of fruit, leaf, petiole, and flower were the main traits. Effective traits were divided into 10 factors explaining 87.85% of the total variation. Factor loading values higher than 0.6 were considered significant. According to the cluster analysis of traits based on Squared Euclidean distance, all genotypes were divided into two main branches, but with decreasing of this distance from 25 to 5, the genotypes were placed into four main sub-clusters. Cluster analysis revealed that the traits of fruit length and its diameter, fruit stalk length and its diameter, fruit taste and color, leaf length and width, petiole length and its diameter, as well as pit length and its diameter were effective for clustering the genotypes.

Panicle size has a high correlation with grain yield in rice. There is a bottleneck to identify the additional quantitative trait loci (QTL) for panicle size due to the conventional traits used for QTL mapping. To identify more genetic loci for panicle size, a panicle developmental trait (LNTB, the length from panicle neck-knot to the first primary branch in the rachis) related to panicle size was identified and the genetic loci were investigated using genome-wide association study (GWAS). Three populations including two subspecies, Indica and Japonica and the whole population were used to perform GWAS by the linear mixed model. Nineteen significant associations were totally identified in the whole population. One locus was examined in both Indica and Japonica. Four associations identified in the present study were near the cloned panicle related genes. Hd16 (Heading date 16) and DST (Drought and salt tolerance) were examined for LNTB. These results indicate that LNTB was also an ideal trait for GWAS to identify the underlying QTLs for panicle size. The associations not related to the cloned genes need to be further validated by the bi-parental populations. Dissecting the favorable alleles of these associations could be helpful for breeding by marker assisted selection in rice.

The presence of morphine alkaloids, anti-microbial and anti-cancer metabolite, sanguinarine, in different species of Papaver genus has made it one of the most valuable plants in the pharmaceutical industry.With regard to the influence of drought and salinity on the increase of secondary metabolites, the present study attempted to investigate the effect of the mentioned stresses on the key genes expression involved in the sanguinarine biosynthetic pathway. Therefore, the expression of BBE1, DIOX2 and DBOX genes involved in the biosynthesis of sanguinarine was investigated under drought (50% FC), salinity (100 mM NaCl) and non-stress conditions in four species of P. somniferum, P. bractateum, P. armeniacum and P. argemone in a factorial experiment based on a completely randomized design with three replications. Total RNA was extracted from leaves and roots of non-stressed and stressed plants, and then cDNA was synthesized and used for quantitative real-time PCR reactions. The results showed that, increases in the expression of BBE1, DIOX2 and DBOX genes in each of four species under drought condition were more pronounced than salinity. In addition, the level of gene transcripts in roots was more than leaves. The expression of each of the threegenes was higher in P. somniferum and P. bractateum compared to P. armeniacum and P. argemone; so that the highest transcription levels of BBE1 (seven-fold), DIOX2 (four-fold) and DBOX (six-fold) in P. bractateum were related to root under drought, leaf under salinity and root under drought stresses, respectively. BBE1 expression in the studied species was more than DIOX2 and DBOX genes, under the mentioned stresses. In fact, according to sanguinarine biosynthesis pathway, BBE1 is a branching point gene and it seems that these species divert the biosynthesis pathway of benzylisoquinoline alkaloids towards the production of sanguinarine by increasing BBEI gene expression under stress conditions. In conclusion, our results support the idea that P. somniferum and P. bractateum could be used as suitable candidates for metabolite engineering and high yield extraction of sanguinarine.