Iranian Journal of Rangelands and Forests Plant Breeding and Genetic Research
Year:2013 | Volume:21 | Issue:1 (41)|Papers Count:16

Precise evaluation of extent and distribution of genetic diversity in rare and endangered species is of particular importance for conserving and utilizing genetic resources. To study inter- and intra-population genetic diversity of three natural populations of boxus (Buxus hyrcana Pojark.) in north of Iran (Bandar Gaz, Nowshahr and Gorgan) ISSR markers were used. Twenty samples per population were randomly selected, their DNA was amplified in PCR reaction using 10 ISSR primers and electrophoretic patterns were obtained. Then, population genetic parameters were calculated based on respective numerical scores. Results showed that there was a desirable genetic variation (34.1%) in the studied populations. However, contribution of intra-population genetic variation in total genetic variation was estimated over than that of inter-population genetic variation (73% vs. 27%). On the basis of Nei’s similarity, a relatively high genetic similarity (74 to 88%) was observed among the populations. The lowest genetic distance (13.2%) was observed between Bandar Gaz’s and Gorgan’s populations and the highest amount (30.1%) was observed between Gorgan’s and Nowshar’s populations. Based on cluster analysis using UPGMA method, populations of Bandr Gaz and Gorgan were grouped together, indicating their higher genetic relatedness and this grouping coincided to geographic distribution. Investigation of Hardy-Winberg genetic equilibrium showed that Bandar Gaz’s population had the highest genetic equilibrium at different loci (~78.9% of loci), while two other populations had a mild equilibrium (58% and 63% of loci in Nowshahr and Gorgan populations, respectively). Gene disequilibrium in the latter populations is probably due to harder endangering forests and losing the hereditary resources of boxus species in the regions. Altogether, on the basis of the results of this research it can be concluded that ISSR markers are efficient and reliable markers for studying genetic diversity and population genetics of Buxus hyrcana species in forests of north of Iran.

Celtis caucasica Willd is one of the native Iranian hard wood trees. The tree is resistant to drought and Dutch elm disease. Therefore, preserving and propagation of elite trees is so important for forest reclamation in semi arid zones. In vitro micropropagation of C. caucasica through bud culture was performed. The best sterilization treatment for shooting was 0.1% HgCl2 solution for 1 min in explants obtained during winter and 5 to 7 min for adult tree obtained during autumn season. DKW medium containing 0.5 mgl-1 BAP, 0.5 mgl-1 2ip was suitable for shoot establishment and multiplication. Plantlets were placed in hormone free medium for two weeks then transferred to main rooting treatments. The best root length growth observed in DKW medium with 0.5 mgl-1NAA. Finally, root treatment of 0.5 mgl-1NAA showed the highest percentage of vitality (99%) in acclimation step in greenhouse.

Genetic diversity of 6 populations of Teucrium polium L., collected from different locations of Iran, was evaluated using random amplified polymorphic DNA (RAPD) data. Total genomic DNA was extracted from young leaves of plants and polymerase chain reaction (PCR) was performed using 8 RAPD primers. Sixty eight bands were obtained of which, 61 bands (89.71%) were polymorphic. All amplified fragments in each sample were scored based on presence (1) or absence (0). Matrix of genetic similarity was calculated by Jaccard's similarity coefficient. Cluster analysis was carried out according to UPGMA algorithm using NTSYS-pc software. The genetic similarity between genotypes ranged from 0.33 to 0.58. Results showed the population Ramian had maximum difference with other populations and classified in a separate group. Maximum similarity was observed between populations Garmab and Maraveh-Tappeh. Our results showed an appropriate level of genetic diversity among the investigated populations. Moreover, our data indicated that the RAPD method is a suitable approach for assessing genetic diversity of T. polium populations with high accuracy.

Drought is one of the most important factors in desert ecosystems that affect plant growth. In this study some of drought parameters were studied on Calligonum persicum, and C. stenopterum, under control and irrigated conditions in a field experiment. Water potential was estimated -34.2 and -27.8 in C. stenopterum and C. persicum respectively. Two species showed no significant differences on praline contents but soluble sugar was significantly higher in C. persicum compared to C. stenopterum. In contrast, relative water content and chlorophyll were significantly higher in C. stenopterum compared to Calligonum persicum. The amount of Na+ and K+ was not significant for the two species. Irrigation significantly decreased water potential in C. persicum and C. stenopterum. Irrigation also decreased proline content in two species, but its effects were significant on C. stenopterum. Irrigation decreased water potential and soluble sugar in C. stenopterum. Comparison of drought effects in control and irrigated conditions showed that osmotic adjustment is active in both species. We concluded that the two species may be able to adapt to their habitats because they are able to adjust their osmotic potential via proline accumulation.

Haploid and doubled haploid (DH) plants are able to accelerate plant breeding programs. This study was conducted on gamma ray irradiated pollen grains of damask rose crosses and induced parthenogenic haploid embryos. Two genotypes of G32 and G40 of damask rose as maternal plant and G22 and mixed of forty collected genotypes from all over the country were used as paternal plants. After determining of suitable collecting time, paternal blooms were irradiated by gamma ray from 60 cobalt in five levels 0, 250, 500, 800 and 1400 Gy. Emasculated maternal flowers were pollinated by the irradiated pollens. Fruits were collected 16 and 19 days after pollination. In order to determination a suitable culture medium the immature embryos were extracted and cultured in three combination of MS medium. To overcome the existing dormancy, half part of embryos was kept at 1-4 degree centigrade for 2 month. Fruit formation percentage and seed averages per fruit depended on ray intensity, maternal and paternal parents. Half MS+vit in was better than the other medium. Chilling was necessary for overcoming the embryo dormancy. On the basis of morphological studies, especially number of chloroplasts in guard cells, the most haploid embryos were obtained by 250 Gy.

To evaluate genetic diversity of wild barley, 115 landraces of barley from five spices as H. vulgare, H. spontaneum, H. bulbosume, H. marinum and H. murinum were planted in a systematic design. Ten quantitative traits were measure according to IBPGRI. Analysis of variance showed significant differences between the landraces for all of the studied traits. Correlation analysis showed a positive and significant correlation between seed number in spikelet and spikelet number. Also correlation between seed number in spikelet with seed length and width were negative and significant. In principle components analysis, three principle components accounted for 78 percent of total variation. The first principle component with 35% explained traits such as spikelet number, seed length and width and seed number in spikelet. The second principle component with 22% explained peduncle outside, peduncle length and spikelet length. The third principle components with 22.38% explained height, node number and leaf number. Cluster analysis also classified the landraces into 3 groups which separated landraces according to the species. The results showed a high level of genetic diversity in wild and landraces of barley which could be used for barley cultivar improvement.

The study was performed in order to estimate water use efficiency and to compare rate and speed of germination of Agropyron cristatum L. accession seeds in hydroponic culture. The seeds were planted under 25oc and %90 humidity conditions. An experiment was carried out with 4 replications in petri dish, each containing 25 seeds (totally 100 seeds per accession). Seedlings were located in unevaporating pots containing Hoagland nutrient solution. An aquarium air pump was used for aerating the seedling roots. Increased dry matter, consumed water and water use efficiency were recorded after one month. This part of experiment was carried out based on a completely randomized design with 3 replications. Recorded data were analyzed by one–way ANOVA method and means were classified by LSD method. Cluster analysis was performed on the data related to increased dry matter and water use efficiency. Results indicated that for the increased dry matter and water use efficiency, the accessions were significantly different. But no significant difference was observed for the consumed water. Means comparison showed that Mianeh and Arasbaran accessions had the highest measurements for water use efficiency. On the basis of cluster analysis, accessions were classified in 4 groups: 1. Mianeh and Arasbaran. 2. Almeh and Semirom. 3. Khoshyeylagh and Parvar. 4. Nebraska, Eskishir, Kurdistan and Veresk. Also, results of the rate and speed of the germination showed that the genotypes had significant differences for both of the traits. It can be concluded that the accessions of Mianeh and Arasbaran had higher water use efficiency.

Amygdalus scoparia L. is an important species of Rosaceae. The species is endemic of Iran and resistant to heat and drought for which, the species has been used in civil green landscape designing projects and endemic byproducts. A. scoparia normally produces bitter seeds, whoever, only one Amygdalus tree with sweet seeds was found among bitter Amygdalus stands in Naein, a city in center part of the country. Due to the importance of the tree with sweet seeds, micropropagation of the single tree would be of interest, particularly for preservation of the genetic resources. Propagation of one tree of each sweet and bitter genotype through micropropagation by bud and embryo culture was performed. Sterilization treatment was done by cleaning and brushing of buds by detergent and 70% ethanol solution, followed by dipping the buds in 0.1% HgCl2 solution for 2 minutes during the spring season for both of genotypes. The suitable method for seed surface sterilizing was washing in tap water and then dipping in 0.1% HgCl2 solution during 1 minutes for the sweet and 3 minutes for the bitter genotype. The best medium for shoot proliferation was DKW along with BA (0.5 mg/l), IBA (0.1 mg/l) and TDZ (0.05 mg/l). Rooting of shoots was done in hormone free medium that followed by placing the shoots in modified MS medium supplemented with 1 mg/l of IBA in dark condition. The plantlets were acclimated in greenhouse.

This study was conducted to evaluate the response of physiological traits of sainfoin to drought stress and to identify drought tolerant populations in a sainfoin collection from Iran. Ten populations were evaluated over two harvests according to a split plot in time design under normal and drought stress conditions. Analysis of variance showed significant difference among sainfoin cultivars for all the measured traits except for chlorophyll a/b ratio and carotenoids content. Drought stress significantly increased proline content while forage yield and other traits were considerably decreased. Under normal moisture condition Fereidonshahr2 and Khansar2 with average values of 37 and 34 ton/ha had the highest forage dry matter yield while in stress condition Isfahan, Fereidonshahr2 and Kerman cultivars produced more forage yield. Proline content increased more than 600 percent under drought stress while relative water content and total chlorophyll content decreased 28 and 14 percent, respectively. The results of cluster analysis in both conditions separated cultivars into three groups identified as tolerant, moderately tolerant and susceptible, respectively. Tolerant cultivars could be used for future breeding studies in developing drought tolerant varieties.

Quantitative genetic diversity is a fundamental component of the interaction between natural populations and their environments; therefore, a better understanding of the nature of the interactions may lead us to more success in breeding programs of different species. Seeds of 60 mother trees of brant’s oak were collected from different latitude and altitude of Zagros forests and sown in a research field of Yasuj, located on the south of Zagross. After two years, several morpho-physiological traits such as efficiency of photosystem II, leaf area and weight, specific leaf area and relative water content of seedlings were measured. Different genetic parameters including heritability, genetic and phenotypic coefficient variation of overall and each provenance were separately calculated. Results showed that the effect of provenances and mother trees were significant for some traits such as efficiency of photosystem II, area and weight of leaf and relative water content. Also these traits had high heritability ranged from 0.8 to 1, whereas in case of specific leaf area, the amount of heritability was zero. The efficiency of photosystem II had also highest amount of genetic and phenotypic coefficient variation (75.8% and 0.8). The amount of heritability was different in each provenance for all measured traits except for relative water content. It was not appropriate to use a single trait in early selection for different provenances in Zagros forests. However, measurement of several morpho-physiological traits such as leaf area, leaf dry and wet weight can help us to select the progenies of the species with higher growth and survival rates in Zagros region.

Relationship between forage yield and its components in first generation of five synthetic varieties were evaluated in a randomized complete block design with three replications at the research farm of Isfahan University of Technology, Iran, during 2010-2011. Results showed significant effects of variation between parents on forage yield. Results of stepwise regression revealed that for dry matter forage yield, flag leaf length explained 61% of observed variation. Path analysis showed that plant collar diameter had the highest direct effect on forage dry matter yield. Plant collar diameter also had a positive indirect effect through plant height and negative indirect effect through number of fertile tillers on forage dry matter yield. However, flag leaf length, number of fertile tillers and plant height had the strongest effects on plant forage yield improvement, respectively.

Chromosomal characteristics of three populations of Stachys lavandulifolia Vahl were studied using Hematoxilin staining of meristamtic root tips. Karyograms of each population were made and karyotypic characteristics including the chromosome number, long and short arms length, arm ratio index and relative length of each chromosome were measured. Results showed that all of the populations had 2n=68 chromosomes and there were differences between the populations in terms of chromosome formula. Chromosome size of the species is small and varied between 0.93 to 2.45 mm in the populations. The base chromosome number of the species is x=17 and it seems that S. lavandulifolia Vahl is a tetraploid species. There was much diversity in the studied populations in terms of most chromosome characteristics. Sarab and Ardabil populations being in the 2A class according to Stebbins classification showed symmetrical karyotype while Meshkynshahr population located in 2B class and had an asymmetric karyotype compared with other populations.

To evaluate the diversity of the collection of Aegilops umbellulata, cytogenetic characteristics of 96 accessions of the collection of Ae. umbellulata obtained from National Plant Gene Bank of Iran were studied by flow-cytometry and cytogenetic. Flow cytometry studies showed that ploidy level of the accessions were diploid. Cytogenetic studies, confirmed the results of flow cytometry. In other words the basic chromosome number of the accessions was X=7. Comparing the results of flow cytometry and karyotypic studies, direct relationship between DNA content and chromosome length was confirmed. The studied accessions contained symmetrical karyotypes with metacentric and submetacentric chromosomes. Satellites were also observed on all of the studied karyotypes. Average coefficient of variation of the accessions was 13.15. Therefore, karyotypic and flow cytometry studies revealed intra- population variation in the species. Thus, given the wide dispersal of Ae. umbellulata in Iran, diversity and evolutionary history of a species were shown in the country.

Onobrychis sativa is a very important legume used as forage in Iran. However, improvement of O. sativa is slow and time consuming, being made essentially by introduction of the foreign genetic material. This study evaluated seed protein profiles of 110 genotypes of O. sativa from 11 populations, to determine the extent of genetic diversity. On the basis of SDS-PAGE, 46 reproducible bands were used for analysis and genetic diversity was estimated based on the number of different protein peptides. The rate of polymorphic bands over the total bands detected ranged from 0.182 to 0.284 with an average of 0.233. SDS-PAGE of seed proteins showed high inter- and intra-population diversity and no clear differentiation on the basis of origin or source. The correlation between genetic and geographical distance matrices was not significance, indicating lack of cline trends in variation of seed storage proteins. It is suggested that the genetic base of cultivated O. sativa should be broadened by involving diverse parents in the breeding program. Expansion of the genetic base for O. sativa breeding might be accomplished by systematic use of germplasm that differs in protein profiles and has better quantitative traits.