مجله پژوهش های ژنتیک گیاهی
سال دوم شماره 1 (بهار و تابستان 1394)

Peppermint (Mentha piperita L., Lamiaceae) is one of the most important medicinal and aromatic plants. Menthol is the major monoterpene constituent of peppermint’s essential oil, which is used for pharmaceuticals, cosmetics and food industries. This work was aimed to study the expression pattern of important genes (Pr, Mfs, Ls) in menthol biosynthesis pathway in different plant’s organs (leaf, flower and stem) at the beginning of flowering stage. The peppermint plants were supplied from Iranian Institute of Medicinal Plants and were transferred into a greenhouse in pots. Analysis of variance showed that there is a significant difference between leaf, flower and stem, with respect to mRNA transcript level. The results of this study indicated that the level of gene expression of Pr, Mfs and Ls were altered in the different organs. There are direct relationship between the content of menthone and menthofuran and level of gene expressions of Pr and Mfs genes in flower and leaf respectively. It can be concluded that probably the expression of Mfs and Pr genes in these organs may be regulated at transcriptional level.

Knowledge about the amount of genetic diversity and understanding relationship between species and landraces is an important step in plant germplasm conservation. In this study, within and between genetic diversity of 17 dill landraces (Anethum graveolens L.) from different areas of Iran was evaluated using five ISSR markers. In total, 29 polymorphic bands were generated. The average of polymorphism was 54.7%. The highest and the lowest values of Polymorphic Information Contents were 0.46 for ((CA)8G primer) and 0.40 for ((AG)8T primer), respectively, and with an average of 0.43. Based on the highest and the lowest indices of Polymorphic Loci (0.392 and 0.248), expected heterozygosity (93.10 and 62.07) and shannon's Information Index (0.567 and 0.360) between all populations, the highest and lowest genetic diversity was detected among Ardebil and Azarshahr genotypes, respectively. The genetic dissimilarity matrix showed that Sari and Kerman populations had the highest genetic distance and Ardabil and Borazjan populations had the lowest ones. Partitioning variations within and between populations, using an analysis of molecular variance (AMOVA), showed that 12% of the total genetic variation existed between growing regions. Cluster analysis based on UPGMA method showed a poor relationship between genetic distance and the geographical grouping of dills.

Yarrow (Achillea millefolium) is an herbaceous and perennial plant species which belongs to the Asteraceae family. Yarrow's essential oil has different compounds of monoterpene and sesquiterpens, which its main constituents are pinene and linalool. These compunds have anti-microbial and anti-pest activities and also can be used in the food industry, perfumery and cosmetics.The aim of the present study was to use the degenerate primers approach in order to isolate Pinene synthase and linalool synthase genes from Yarrow plant. Up to date, there is no any report on the availability of these genes in the world gene bank. In this investigation the total RNA was extracted from Yarrow then pinene synthase and linalool synthase genes were isolated, using degenerate primers and Polymerase Chain Reaction (PCR). PCR amplified two bands of 250 bp and 720 bp. The sequence data were compared with NCBI gene bank data. The results of diversity study among varieties and families based on Pis and Lis genes showed most similarity between Achillea and Artemisia plants. Also this similarity was seen between Asteraceae and Lamiaceae families and these families grouped together same group. These results also showed a relatively high similarity of Pis and Lis with some other plants which confirmed sequencing data.

In this study, genetic diversity of 25 rainfed bread and durum wheat genotypes were assessed using 20 SSR primers that all of them were generated scorable bands. Totally 69 alleles (ranged between 2 allele for Xcfd40 and Xgwm369, and 5 allele for Xbarc54 primers per each locus), were distinguished. Polymorphic information content (PIC) for all SSR primers was calculated. The highest (0.98) and the lowest (0.64) amount of PIC was pertained to Xcfd40 and Xgwm30 primers, respectively. Based on similarity matrix, the highest and lowest genetic similarity was belonged to Seri82 and Seri (0.86) and Sita/chil and Baviacora (0.14), respectively. Cluster analysis could distinct spring and winter wheat genotypes and as well as bread and durum wheat genotypes. It was concluded that SSR marker was suitable for evaluation of genetic diversity in rainfed wheat genotypes. This genetic diversity can be used in wheat breeding programs.

To estimate the genetic components and the mode of inheritance for some morphological traits, six rainfed durum wheat genotypes (Chehel daneh, Gerdish, Zardak, Syrian-1, Waha and Knd1149//68/ward) and their complete diallel progenies were grown in a randomized complete blocks design with two replications in 2005-06 cropping season in Maragheh Dryland Agricultural Research Station. Results of diallel analysis revealed that additive variance were important for inheritance of grain yield, number of grain per spike, spike length and number of fertile tiller than dominance variance. The positive value of ‘F’, indicated that there were excess of dominant alleles in comparison to recessive ones in the parents for all of the studied traits. The average degree of dominance (H1/D) 0.5 showed partial dominance for grain yield, number of grain per spike, spike length, 100 grains weight and number of fertile tiller and over-dominance for peduncle length. Graphic analysis indicated that increase of grain yield, number of grain per spike, spike length, 100 grains weight and number of fertile tiller were under the control of combination of recessive and dominance alleles. Predominance of additive effects for grain yield demonstrated that breeding methods based on selection may be advantageous in improving of this trait. The highest value of this trait relevant to Gerdish (10.33 g/plant), therefore this genotype can be used as cross parent in breeding programs for receiving to lines with high yield and yield components. The cross of Waha × Knd1149//68/ward with high value of GY and GCA for this trait can be used as a suitable cross for hybrid production.

In order to identify the correlation between different agronomical traits and the study of their relation using regression analysis, 46 alfalfa populations were studied in the research farm at Bu-Ali Sina University in 2013. Analysis of variance for different traits revealed a significant difference between populations for dry forage yield at the level of 1% probability. The genotypic ccorrelation coefficients of fresh forage yield with the amounts of leaf chlorophyll (SPAD) (0.952**), plant height at 10% flowering stage with fresh forage (0.987**), dry matter yield with fresh forage yield (-0.942**), dry forage yield with plant height at 10% flowering stage (0.676*) and dry matter percent (0.896*) showed significant correlations. Phenotypic correlation analysis showed a positive and significant correlation between damage percent and the number of larvae (0.767**), a negative and significant correlation between dry material percent and fresh forage yield (-0.450**). However, dry matter percent had a negative and significant correlation with dry forage yield (0.424**). The stepwise regression for fresh forage yield as dependent variable showed that dry forage yield, dry matter percent, plant height in 10% flowering stage and number of larvae were respectively entered to the model and with 89.29% of cumulative contrast coefficient confirmed the most variations of fresh forage yield. Furthermore, the maximum and minimum heritability percent was depended to the number of Larvae and dry forage yield respectively. Naragamet population (No. 30) with a high yield of dry forage and the number of larvae and also a relatively low level of damage percent among other populations could be suggested as a desirable and tolerant population