Iranian Journal of Rangelands and Forests Plant Breeding and Genetic Research
Year:2012 | Volume:20 | Issue:2 (40)|Papers Count:14

Aloe Vera L. is one of the medicinal plants with different uses in pharmaceutical, cosmetic and food industries. According to increasing demand for the plant species, the most studies of tissue culture have been focused on micropropagation. But somatic embryogenesis as an appropriate way for large scale propagation, production of synthetic seeds and production of secondary metabolites have been ignored. The effect of plant growth regulators including a- Naphtalene acetic acid (NAA) and N6- Benzyladenin (BAP) and vitamin combinations including MS, LS, L2 and modified vitamin were studied, in this work. MS medium with modified vitamin including 0.4 mgl-1 Thiamine HCl plus 0.5 mgl-1 Prydoxine HCl plus 0.5 mgl-1 Nicotinic acid plus100 mgl-1 Myo-Inositol, supplemented with1.0 mgl-1NAA induced 100% callus induction. The most indirect somatic embryogenesis (50%) was induced by applying MS culture medium with modified vitamin supplemented with 0.2 mgl1 NAA and 5.0 mgl1 BAP.Eighty percent of plantlet regenerated from somatic embryos was survived after maturation, plantlet production, and acclimatization.

The full text of this article is the Persian language, please for the view full text, refer to Persian Please click here to view the full text of this article

The full text of this article is the Persian language, please for the view full text, refer to Persian Please click here to view the full text of this article

Iran is one of the most important diversity centers for plant species, and of the origins of subgenus Cerasus, such that nine wild species of this subgenus are found in Iran. Marmareh (Prunus incanaPall.) is a native plant of north-west temperate regions of Iran, belonging to this subgenus. In this study, nineteen morphological traits were used to evaluate genetic diversity of five natural populations of Marmareh. Results showed that the tallest trees were in accessions of Ahar population and the shortest trees in Tabriz population. Results of simple correlation analysis showed significant positive or negative correlations among some important traits such as tree height, leaf area, leaf serration, fruit and stone weight, length and diameter. In addition, factor analysis categorized effective characters within the first three factors. The factors explained 91.70% of total variance. Characters such as leaf area, leaf blade length and width, petiole length, fruit and stone weight, fruit length and diameter and stone volume contributed in the main factors. Cluster analysis was performed using the first three factors and clearly discriminatedP. incana wild populations from other Prunus species, such that in distance of 25 sweet and sour cherry accessions were separated fromP. incana and mahaleb accessions. Since the mahaleb accession was intermediate in the traits of the first main factor, it was separated from sweet and sour cherry.

Six populations of Quercus castaneifolia collected from north of Iran, were examined for karyotype analysis. Microscopic samples were prepared and studied, using their root meristem after pretreatment, fixation, hydrolysis and staining stages. Results showed that the basic chromosome number of all populations was x=12 and all of them were diploid. The populations' differences were investigated using variation analysis and their means were compared based on 5 chromosomal parameters: total length of the chromosomes (TL), long arm (L), short arm (S), arm ratio (AR) and centerometric index (CI). The results showed significant variation among the populations in TL, L and S. Karyotipic formula for all of the populations was 12m. The karyotypes were classified in class B of Stebbins classification. The asymmetric parameters defined moderate asymmetry in all of the studied karyotypes. Principal components analysis based on karyotypic parameters showed that TL and L play the most important role in the first component. The first component contained more than 64% of total karyotypic variation.Cluster analysis classified the populations into two classes. The Gilan province populations was assigned to one cluster and Lo’ve, Lajim and Kelardasht populations allocated to another one.

The full text of this article is the Persian language, please for the view full text, refer to Persian Please click here to view the full text of this article

The full text of this article is the Persian language, please for the view full text, refer to Persian Please click here to view the full text of this article

Populus euramericanais one of the most important species for agroforestry in Iran.Nowadays, several non-native clones of the species have been imported to the country. But their individual differences are unknown and important to us. The objective of this research was to determine the differences among five clones of the species based on two important enzymes, peroxidase and catalase as environmental bio-indicator from late summer to early spring.Therefore, quantitative activities of the enzymes were studied by spectrophotometry method on asexually propagated seedlings of the clones. Results indicated that the majority of the differences for peroxidase and catalase were observed during March and January respectively.Generally the results showed that peroxidase activity of clone 45.51 during the beginning and the end of growing season and also both enzymes activities of clones 561.41 and I214 had the highest differences with other clones during the cold months of the year.

Effective use of water resources should always be considered for optimum growth of plants.To determine different levels of water deficit stress effects on several physiologic characteristics of Fortuynia bungei a completely randomized design was conducted with three treatments and three replications, during 2011. Water stress treatments consisted of 100, 50 and 25% of field capacity. Results showed that increasing water deficit stress led to decreasing in water potential, specific leaf area and increasing in prolin (P<0.01). Maximum prolin (39.3 mg g-1 fresh weight), minimum water potential (-33 bar) and minimum specific leaf area (17.224 cm g-1) was observed on 25% of field capacity. The overall results of this study showed that the species is adaptable to dry conditions by using water stress tolerance mechanisms such as reduced water potential of leaves and increased levels of prolin accumulation. Fortuynia bungei can be considered as a suitable plant for increasing the capacity of desert areas, pastures and urban green space for better utilization of water resources.

In this research study, tree rings widths of beech tree, obtained by the cores, from different elevation were analyzed, to study variability in Fagus orientalis Lipsky. This investigation provides a new approach to use Dendro-Genetic Method in line of dendrochronology to recognize phenotypic variability in forest trees. Results provided in this research, is part of a wide range of dendrochronology study which have been taken during last five years to consider climate change impacts on Hyrcanian forest ecosystems. Target species in this study is Fagus orientalis collected from Korkoy forest district in Golestan province. Sample cores were collected along a transect line (profile) in three elevation levels, namely 366, 1236, and 1646 meters above sea level. Genetic variability was considered in relation to the different climatic and environmental factors. According to this method that implied in very wide range, possibility of recognition of phenotypic variability was examined. The experiment results indicated that based on the studies on trees through genetic dendrochronology, the existing diversity of the species may be investigated.

Eighteen species of Poa grow in Iran. Several introduced species of Poa are economically important. The species are commonly cultivated for lawns and pasture, and are a major forage species. In addition, they are widely planted for soil stablization and forage. Cytogenetic studies are very important for the aim of genetic improvement. Therefore, quantifying interspecies chromosome variation can provide important information for plant breeders. In order to study cytogenetic characteristics of Poa L., karyotypes of 4 species were analyzed using image analysis system. The basic chromosome number was x=7 for all of the studied species. But their ploidy levels varied indicating chromosome variation among the studied species. Variance analysis showed significant differences (P<1%) among the species for all of the recorded traits indicating chromosome measures variation in the studied germplasm. According to Levan method on chromosome type, all of the studied species had submetacentric chromosomes (Sm) that implies asymmetric karyotype for the species. Based on Pearson correlation method long arm length, short arm length and total chromosome length were inter-correlated (P<1%). CI had negative correlation with AR (P<1%) and number of chromosomes correlated with long arm length, short arm length and total chromosome length. LSD test showed significant differences (P<5%) on long arm length and total length in Poa strilis and Poa pratensis, for long arm, short arm and total length between Poa strilis and Poa angustifolia and for short arm length between Poa araratica and Poa angustifolia.

Eucalyptus species belongs to Myrtaceae family and native of Australia. Eucalyptus rubida with medicinal usage is a fast growing tree species, with high wood yielding.Iran is a country with low cover forest, therefore, it is suitable for silviculture programs in some part of the country. Auxins and cytokinines are two main groups of growth regulators with different concentrations, having important role in callus formation and in somatic embryogenesis as well as organogenesis stages. Requirement of seedling production of E. rubida was the reason for this study. Effects of 2, 4-D and TDZ as the growth regulators on callus production and organogenesis of the species was investigated.E. rubida seeds were sterilized and cultured on MS medium with half of required nitrate concentration for a large number of sterile seedlings production.Explants of cotyledon, root and stem of the seedlings were planted on MS medium with nine different treatments of TDZ and 2, 4-D hormones levels in order to callus formation and then organogenesis phenomena. The best recognized treatment for callus production was: TDZ with 0.5 mgl-1 and 2, 4-D with 1 mgl-1; for organogenic callus production was TDZ: 0.1 mgl-1, 2, 4-D: 1 mgl-1 and for embryogenic callus production was TDZ: 0.5 mgl-1, 2, 4-D: 0.5 mgl-1.

In order to compare genetic variation, 36 accessions of Festuca arundinacea were surveyed in random complete block design under dry land farming conditions, with three replications. Some morphological traits and forage yield of each accession were recorded.There were significant differences between the accessions. Accessions 6, 15, 7, 26, 20, 31, 16 and 4 had the highest value for forage yield whereas, accessions 17, 10 and 29 had the lowest values for forage yield. Also, significant phonotypic correlations were observed between forage yield and other studied traits. Among the studied vegetative traits, plant height indicated positive and significant correlation (p≤0.01) with the other traits (except with leaf width). Cluster analysis and mean comparison among the groups resulting from cluster analysis verified the results. Using factor analysis, three factors could be identified after Varimax rotation. The independent factors accounted for 70% of the total variance. The first factor indicated vegetative traits, sceond factor indicated spike length and number spiklet per spike and the thired factor indicated generative traits. Based on the results, accessions 3, 31, 32, 36 and 6 were superior for yield and vegetative traits and could be introduced and suggested to produce artificial cultivars in breeding program under dry land farming conditions in Kermanshah province.

In order to study reproductive traits variation of Mentha genotypes, an experiment was conducted on 19 Mentha genotypes belonging to fives species in a randomized complete block design with 3 replications at Fozve Research Station of Isfahan Agricultural Resource Research Center. Pollen length and width, viable and dead pollen percentages, number of pollen per anther, number of female flowers, number of complete flower per main spike, number of self pollinated seeds, number of open pollinated seeds and number of cross pollinated seeds were recorded. Results showed significant differences between all of the studied traits. Based on correlation coefficient between the traits, the number of open pollinated seeds, self pollinated seeds and cross pollinated seeds increased by increasing the number of complete flower, length and width of pollen seed, the number of live pollen seed and the number of pollens in anther.Stepwise regression showed correlation between increasing of self pollination and open pollination seed yield with number of viable pollen percentage and number of pollens in anther.Cluster analysis on 19 genotypes classified the genotypes into 4 groups. Mean comparisons among the groups showed suitable variation. The results also showed crossing possibility between the studied species. In essence, there was enough variation between the genotypes to be used in breeding projects.