Journal of Plant Molecular Breeding
Volume:7 Issue: 2, Summer and Autumn 2019

The Hyrcanian forests have a remarkable variety of moss species which research on their taxonomy is of great importance. Since Forsstroemia remotifolia, Homalia besseri and Pseudoleskeella catenulata are exclusive and native mosses species of Hyrcanian forests, so in the current study, fourteen populations from three provinces in the north of Iran including Golestan, Mazandaran and Guilan were collected at the same altitudes in autumn 2017. In order to reveal the relationships among these species and populations, a cluster analysis based on numerical taxonomy and zymogram patterns of peroxidases and superoxide dismutase with Euclidean distances was performed. Numerical taxonomy analysis showed plant length, marginal laminal cell length and middle laminal cell length are appropriate traits to distinguish the species of F. remotifolia, H. besseri and P. catenulata from each other as well as their populations. The zymogram analysis showed genetic variability among species and also within populations of F. remotifolia, H. besseri and P. catenulata. Accordingly, the isozyme banding pattern of peroxidases showed a total of 6, 7 and 5 bands for F. remotifolia, H. besseri and P. catenulata, respectively. However, 4 isozyme bands were detected for superoxide dismutase for all three species. Furthermore, the morphological analyses in some populations was not matched with the isoenzyme banding pattern of enzymes in the current study. In conclusion, the biosystematics studies (morphometry and zymogram patterns of peroxidase and superoxide dismutase) indicate the close relationship between F. remotifolia and P. catenulata.

Chloride is considered as the most important micronutrient in tobacco production. But excessive amounts of chloride accumulation in leaves of tobacco have many adverse effects on the tobacco quality, such as burning capacity. Identification of quantitative trait loci (QTL) involved in chloride accumulation would be beneficial for the improvement of tobacco quality. The objective of this study was to identify genomic regions associated with chloride accumulation by using a mapping population consists of 225 F2:3 families derived from hybridization between ‘Basma Seres 31’ and ‘SPT 406’ lines. Linkage map was constructed with 23 microsatellite (SSR) and 29 inter simple sequence repeat (ISSR) polymorphic markers which covered 570.8 cM of the tobacco genome. Thirty-four of these polymorphic markers were mapped to 7 linkage groups. Distance between two adjacent markers was 17.3 cM. Composite interval mapping (CIM) was used to identify QTLs controlling chloride accumulation. One QTL for chloride accumulation was identified on linkage group 3. The percentage of phenotypic variance (R2) explained by this QTL was 12.7%. A significant association was not found between ISSR markers and chloride accumulation. The outcome of present effort can be a basis for marker aided selection (MAS) in tobacco breeding programs.

Buxus hyrcana is one of the endangered and evergreen species of the Hyrcanian forests in Iran. The genetic diversity assessment is an essential step towards the conservation of this species. High-quality DNA is required for molecular markers analysis; therefore, we compared different DNA extraction methods on leaf samples of B. hyrcana. The quantity and quality of the extracted DNAs were evaluated by spectrophotometry and gel electrophoresis. Also, ISSR (Inter simple sequence repeats) markers were applied on the extracted DNAs to compare their quality for PCR amplification. Results showed that quantity, quality, and PCR efficiency and reproducibility were different for DNA extracted using different methods. The quality of the DNA at the absorbance A260/A280 ratio ranged from 1.02 to 1.97. The highest concentration of DNA measured by spectrophotometry belonged to the Cota-Sanchez extraction protocol (695.3 ng/ml) and the lowest value was obtained with Edward4 method (204.7 ng/ml). The modified Onate method (Onate2) was extracted the highest DNA concentration by comparison of brightness against the DNA ladder. Among the different extraction methods, the good quality and quantity were obtained in extracted DNA for Doyle and Doyle, Cota-Sánchez and modified Onate protocols; the latter method (Onate2) created both good quality and quantity of extracted DNA and operated effectively in terms of cost and time. Onate2 had the best amplification results with ISSR primers.

Salinity stress effect especially the highest concentration (2 dS m-2), was significant for all traits including plant height (PH), number of flowering branches (NFB), number of leaves per plant (NLP), stem diameter (SD), fresh shoot weight (FSW), fresh root weight (FRW), dry shoot weight (DSW), dry root weight (DRW), root length (RL), number of hairy roots (NHR), number of main roots (NMR), root diameter (RD),  total chlorophyll content (TCC), chlorophyll a (Cha), chlorophyll b (Chb), carotenoid content (CC), root sodium content (RSC), leaf sodium content (LSC), leaf potassium content (LPC), protein amount (PA), proline magnitude (PM), peroxidase (POD), catalase (CAT)and decreasedthe measured traits compared to the control. NaCl at 2 dS m-2 induced- salinity reduced the number of leaves per plant by 43.58% compared to the control. The highest number of hairy roots (19.78) was observed in salinity treatment with 0.25 dS m-2, which was accompanied by a significant decrease with increasing sodium chloride concentration to 2 dS m-2. The total leaf protein content, proline accumulation and antioxidant activity of catalase and peroxidase at the highest salt concentration (2 dS m-2) showed a significant increase compared to control. The results of this experiment indicate that the tolerance of the herbaceous medicinal plant to salt stress is induced by increasing the accumulation of proline, soluble proteins and antioxidant enzymes activity.

The mutation in the meristem layers creates different genetic backgrounds (chimera) in the plant tissue. The mutation in L1 layer of shoot apical meristem generates a periclinal chimera. UF3GT is an effective enzyme in floral coloration, inducing anthocyanin accumulation in petals. This study investigates direct and indirect regeneration systems and different explants to propagate two cultivars of periclinal chimera (Saintpaulia ionantha), namely Taro taraneh and Aghaz, using in vitro culture. The evaluation of UF3GT gene expression pattern by Real-Time PCR revealed the role of anthocyanin accumulation in the petal coloration of chimera plants. Results pertaining to both cultivars showed that inflorescence and leaf explant had the highest and lowest percentage of pinwheel phenotype, respectively. In addition, mutant characteristics were faded in the leaf regeneration of periclinal chimera. Furthermore, the highest percentage of periclinal chimera was generated in direct regeneration. Gene expression analysis revealed that UF3GT was expressed in the colorful part of chimera petal, while UF3GT expression was significantly reduced in the muted part. HPLC chromatogram also detected that cyanidin and delphinidin components were not present in the white part of either cultivar. The anthocyanin biosynthesis pathway appears to be blocked and anthocyanin accumulation does not occur in the petals. Inflorescence is likely to induce a pinwheel pattern in regenerated plants, probably owing to its lateral bud. It seems that different meristem layers are associated with the formation of epidermis and induce pinwheel phenotype.

Groundnut (Arachis hypogaea L.) is one of the major oilseed crops of the world and it is an important source of protein in many countries. To study the nature of combining ability and heterosis for yield and related attributes a 4 × 4 full diallel experiment was conducted at the experimental plot of Bangladesh Institute of Nuclear Agriculture, Mymensingh, Bangladesh. Data on various quantitative traits including yield were recorded. Significant differences among the parents and their hybrids were observed for yield and related traits. The analysis of variance for general combining ability (GCA), specific combining ability (SCA) and reciprocal combining ability also showed significant variations for all the studied traits. The GCA and SCA reflected that these traits were controlled by both additive and non-additive genes. Predominant regulation by non-additive gene action suggesting selection at a later generation would be much effective. Significant reciprocal effect for all the traits indicates role of maternal effect in the expression for these traits. Genotypes GC (24)-1-1-1 and China Badam were found suitable combiners for number of seeds per pod, 100-pod weight, 100-seed weight, shelling percentage, and yield per plant. Result of mean and GCA suggested that the genotypes have good ability to transfer these important quantitative traits. The SCA and heterosis revealed that the F1 obtained from the cross GC (24)-1-1-1 × China Badam was suitable specific combiner among the F1’s for most of the traits. The F1 may further be exploited for isolating the desirable segregates of these traits for maximizing yield.

Tuber species are edible fungi and plant-symbiotic microorganisms that form a beneficial relationship with the roots of certain trees and plants (ectomycorrhizae). After interaction with a plant host, tuber species produced hypogeous fruit bodies of great economic value known as forest truffles. There are different species of truffles, but based on species and place of origin varied their quality and market price. Truffle identification is based on morphological analysis maybe fail to distinguish them due to highly susceptible to environmental conditions. But using molecular markers to identify truffles can be more accurate, less expensive and reliable monitoring. In this context, twelve inter-simple sequence repeats (ISSR) primers were chosen for amplifying the genetic materials of black and brown truffles. In this study, a total of 57 polymorphic bands were amplified (an average of 5.18 bands). The Polymorphism Information Content (PIC) value and gene diversity (H) was with an average 0.37 and 0.50, respectively. During the ISSR screening good amplification products were obtained from primers based on GA, (AG) G, (AG)T, and GAC repeats. The population analysis result revealed that there are three main clusters A, B and C. Four strains Ardabil, Khalkhal, Zanjan and Urmia were identified to be in the group A cluster.  The strains of at second and third groups were black and brown truffles respectively. The results indicated that truffles had two separate speciation events (DK = 2). According to DK = 2, the samples of Ardabil, Khalkhal, Zanjan and Urmia grouped in the same group and rest of truffles in other groups.