فصلنامه گیاه و زیست بوم
پیاپی 29 (زمستان 1390)

Vitro culture systems have a hight efficiency for mass propagation of desired disease-free plant as well as genetic improvement. Considering these facts and the importance of olive crop, some experiments were carried out to investigate the effects different carbohydrates on vitro culture Rashid cultivar. For this purpose, single lateral nods were taken from mature tree growth Rashid olive cultivar. Explants were disinfected using 15 % (w/v) NaoCl for 15 min and rinsed 3 times with steril distilled water. After sterilization, nodal segments were cultured to initial culture medium consisting OM and modified MS supplemented with 3 mg/l BAP and carbohydrates of sucrose or manitol with 18 and 30 g/l concentrations. The results showed that different levels of sucrose and mannitol, had significant effects on the number of shoots and nodes formed per explants. The best results of establishment and subculture gave initial culture medium supplement with manitol. Modified MS containing mannitol (30 g/l) improved the best growth position in the establishment and subculture stages for explants

The DNA extraction with high quality and quantity is one of the basic necessity of genomics,.DNA possibility was extracted from different tissues of plant but it is better to extract them from fresh tissues. There are some different secondary metabolites as: Tannins, Terpenoids, Alkaloids and etc. that cause result to difficulties in DNA extraction, Therefore finding a way to reduce these metabolites is necessary, because the base of some molecular researches like genetic engineering and genomics are DNA with high quality and quantity.In this research DNA had been extracted in the Apiaceae family from different organs and tissues like as fresh leaves and stems of The dill (Anethum graveolens) and callus and non-differentiation tissues (meristemic tissues) of Ducrosia anethifolia, Dutora steramonis, Artemisa annua, Aloe vera and etc.The quality and quantity extracted was used agarose gel 1% and spectrophotometer method. Results show that genomic DNA that had been extracted are partly pure and desirable, if there were some infection with metabolic components have the purification methods would be used.

Haloxylon species have several capabilities for which they can resist harsh conditions of deserts as well as playing an important role in the fixation of sand dunes. Accordingly, progenies of 27 mother trees collected from their habitats were studied in a repeated statistical experiment. Heritability values were estimated for vegetative characteristics of plant height, crown diameter, and collar diameters of the single plants. Analysis of variance revealed that the genotypes were significantly different in all the six years of the study but the level of significance were lower for early years than that of last year of the study period. Genetic components of variance and heritability also showed an increasing trend during the study period. The difference between the mother plants were more remarkable in final year of the study period, implying that due to low vegetative growth speed of the species, it would not reveal its complete potentials at early growth stages. The result showed medium significant correlation of investigation. Traits Plant hight, Survival, Crown smaller diameter, Heigh of first branches and Number of branches on main inter to model studied by path analysis. Result showed that Plant hight, Survival, Number of branches on main hand has the greatest direct and positive effect on Crownlarge diameter. Likewise, 4 principal components approximately explained 71.5% of total variance. Totally, in order to increase the coverage and improve direct crown large diameter, respectively, both principal components should be considered. In other words, plant height, survival and the number of branches in the main hand were the topics that should be highly regarded.

The role of xylem vessel dimensions and some anatomical attributes in relation with it for occurrence of various rates of resistance to Dutch elm disease in elm trees is probable. The present research was carried to compare the xylem vessel diameter and some anatomic traits related to it in Ulmus glabra, U. carpinifolia var. umbraculifera and U. parvifolia as the important factors of host-resistance to Dutch elm disease. In this experiment, in addition to estimate the diameter of vessels, indexes of percentage of vessel transactional area, percentage of vessels greater than 100 micrometer and rate of relative theoretical hydraulic conductance were calculated in the second and third-year-rings for the elm species. The results showed that significant difference at probability level 1% was among the calculated indexes of the elms, so that U. glabra had the vessels with more diameters than U. parvifolia and Ulmus carpinifolia var. umbraculifera. The percentage of vessel transactional areas and vessels greater than 100 micrometer were calculated for U. glabra more than U. parvifolia Ulmus carpinifolia var. umbraculifera. The relative theoretical hydraulic conductance index was also received significantly for U. glabra the highest rate of the rest. The U. parvifolia showed the least rates of measured indexes in this experiment. Totally, being of the significant differences among cited anatomical indexes for U. glabra and U. carpinifolia var. umbraculifera, susceptible to Dutch elm disease, and U. parvifolia, resistant to Dutch elm disease, Ophiostoma novo-ulmi, could be affected to indicate agent or agents of host-resistance with respect to Dutch elm disease that were discussed in this paper.

In order to study the genetic variability in Elymus hispidus, 19 populations from two sub species of Agropyron trichophorum and Agropyron Intermedium were examined in field and germinator during 2006-2008 in Tehran Iran. Data were collected for heading date, plant height, stem number, spike length, forage yield, seed yield and seedling traits (seed germination, speed of germination, seedling length and vigor index). Results showed significant differences between two species for all of traits except vigor index. The A. intermedium populations had higher values from A. Trichophorum. Phenotypic correlation were positively significant among seed yield, plant height, stem number, spike length and dry matter yield. Using principle components analysis (PCA) based on morphological data, the first three components accounted for 87 of total variation. Plant height, stem number, spike length, dry matter yield and seed yield were important traits. In the second component seedling characteristics (seed germination, speed of germination, seedling length and vigor index) and in the third component phenological traits were the most important for classification of populations. Using ward cluster method, the 18 genotypes were classified correctly into two same groups as their species. The distribution of genotypes based on (PCA) analysis was in agreement with cluster analysis.

In order to study the correlation between traits in white bean genotypes, an experiment was conducted using a randomized complete block design with four replications in 1386-87 years. In this study 30 varieties were evaluated for 18 traits. Results of variance analysis showed significant differences between varieties of all traits. Simple correlation coefficient was significant between yield and weight of pod, biological yield, number of seed per plant, number of pod per plant, plant height, width of pod and number of seed per pod traits at 1 percent level. According to stepwise regression seed yield trait was considered by dependent variable and weight of pod, harvest index and biological yield traits by independent variables. Model determination coefficient was R2=0.68. The most of determination coefficient was for weight of pod. Path coefficients analysis showed that the highest direct effect of weight of pod relation to other traits affected the seed yield. Principal component analysis and cluster analysis was confirmed above the results. Therefore the most important traits to select index for seed yield improvement were weight of pod, harvest index and biological yield.

English yew (Taxus baccata) is one of the limited coniferous species in Caspian forests of Iran. Taxol, unique drug employed for the bark of Taxus species. A factorial experiment was carried out to find the best combination of media and plant regulators. Micropropagation carried out to find apartical method for mass propagation. In this research two kinds of media (MS, MS(½ nitrate)), two various plant regulators (BAP, Kin + IBA), one explants (shoot tip) and presence or absence of 2 g/l active charcoal were studied. For root induction elongated shoots after 1 month were cultured on MS, ½ MS, WPM, ½ WPM media supplemented with levels of 2 growth regulators including (IBA, NAA) or without growth regulators. The best treatment for new growth leaves was the use of MS media with 3 mg/l Kin in combination activated charcoal 2 g/l and the best response (2.67 cm) was observed on MS medium with 3 mg/l Kin and also 3 mg/l BAP in combination activated charcoal 2 g/l for shoot elongation. After 2 months rooting of T, baccata was obtained on WPM in the absence of growth regulators. The best elongated shoots were on media containing lower concentration of plant growth regulators. Auxin and cytokinin were important on the elongated shoots. BAP was also found to be effective in inducing shoots and shoots elongation.

In order to study G*E on yield of 17 wheat irrigated lines and 3 varieties in different environment under late season water stress this research was done. These genotypes were planted with an RCB design with 3 replication in three regions; Esfahan, Kermanshah and Varamin. The results combined analysis of variance for yield showed the significant differences among genotype effect, environment and G*E interaction effect as well. After stability analysis methods of Eberhart and Russell, Wricke and Shukla were used to determine the best genotypes for yield. Based on Eberhart and Russell's method in experiment genotypes 14 and 15 had regression coefficient near to 1 and higher grain yield was known as genotype with good adaptability to all environments. Based on Wricke and shukla stability analysis was obtained, and genotypes 19, 16, 15 and 6 were known as stable genotype.

Selection of cultivars with high genetic potential and favorable climatic adaptation in each region and exact planting date for maximum utilization of effective factors growth are the necessary management for improvement of soybean yield. Therefore, the effect of planting dates of 19 May, 29 May, 8 June and 18 June on yield and yield components of four intermediate soybean cultivars i.e. Williams, Zan, L17 and M7 was carried out in a split plot based on randomized complete blocks design with four replicates. Using analysis of variance showed that planting date cultivar affected on all traits at one percentage level was significant (P<0.01) planting date on 19 May had the most effect on the traits and the cultivars cultivated on 18 June had the least yield. cv. Williams had the highest values for all of traits.cv. L17 had the least seed and pod numbers, protein and oil yield and cv. Zan had the least seed and pod yield and pod shell weight. Interactions of the factors showed that cv. Williams had the most pod and seed numbers per square meter on 19 May. cv. Williams had the most protein yield (107/3 kg /ha), oil yield (40 kg/ha), seed yield (251.5 kg/ha) and pod yield (356.5 kg/ha) on 29 May.