مجله علوم و فنون باغبانی ایران
سال چهاردهم شماره 3 (پاییز 1392)

In study the effects of different concentrations of maleic hydrazide (100, 200, 400, 600, 800 and 1000 μM), boric acid (25, 50, 75 and 100 mM), silver thiosulfate (0.25, 0.5, 0.75, 1 and 2 mM), sucrose (1, 2, 5 and 10%) and deionized water (control) on vase life of lisianthus cut flowers cv. ‘Purple’ two separated experiments were conducted based on completely randomized design for 24 hrs at 22 ± 2 oC. The results of experiment revealed that significant differences (P>0.05) were found on vase life, relatively fresh weight and solution uptake between control and other treatments. The results also showed that boric acid at 50 mM increased vase life of flowers compared to other concentration. Cut flowers treated with 5 and 10% sucrose significantly extended vase life of flowers compared to control. Moreover, silver thiosulfate significantly improved the vase life of flowers and the greatest vase life obtained from 0.5 mM. Maleic hydrazide at 600 and 800 μM considerably increased flowers vase life. Chlorophyll amount of treated flowers was more than control, however, no significant differences were found.

Among micronutrients, iron plays an important role in plant nutrition. Iron deficiency which appears more in young leaves as iron-chlorosis, has been considered as one of the most important nutritional insufficiency in plants severely affecting yield and crop quality. In this study, two iron sources including iron sulfate and iron chlate (Fe-EDTA) were applied to apple ‘Red Delicious’, peach ‘Anjiri’ and nectarine ‘Moghan’ trees with iron deficiency through adding to the soil, foliar spray and bark injection. Experiments were carried out for any of fruits separately in randomized complete block design with 7 treatments and 3 replications. In the soil application method, 50 g of each iron source was separately added to the soil surrounded each tree in early June and well-mixed. In foliar spray and bark injection methods, 0.5% of each iron source was applied three times separately (early June and repeated twice every four weeks). The intensity of leaf chlorosis and the leaf color changes were visually monitored and recorded during the experiments and the amount of chlorophyll in leaves was measured by spectrophotometer after fruit harvest. The amount of active and total iron of the leaves was also determined using an atomic absorption instrument. Iron treatments had significant effects on the chlorophyll content as well as active and total iron of the leaves in all tree fruits. The lowest amounts of leaf chlorophyll and active iron was obtained from the control (no fertilizer) and the highest amounts belonged to the bark injection of iron sulfate, while the highest amount of leaf total iron in the apple and peach trees obtained from the control and in the nectarine trees belonged to the iron sulfate bark injection.

Understanding the patterns of color changes in flowers and ornamental plants will be useful in breeding programs for production of novel and in demand cultivars. In this study, flower color changes and interaction of parameters affecting color were investigated and compared during three developmental stages and coloration of flowers in six cultivars of gerbera. Results showed that in different cultivars, flavonoids biosynthesis is started very earlier than flower blooming stage and prior to bud formation. Two types of anthocyanidins pigments; cyanidin and pelargonidin were also analyzed. Results showed that in all cultivars except in ‘Bastion’, ‘Double Dutch’ and ‘Eco’ cultivars that lacked pelargonidin pigment, cyanidins and pelargonidins were increased correspondingly to petal tissue evolution, but their ratio varied in different cultivars and during different flower developmental stages.

In this study, we investigated the effects of carvacrol, thymol, zataria oil and silver nanoparticles on flower senescence in Alstroemeria cut flowers cv. ‘Sukari’. Results showed that carvacrol (50 mg L-1) and silver nanoparticles (5 mg L-1) significantly delayed senescence of Alstroemeria cut flowers (P≤0.01), such that floret abscission started 9.83 days after carvacrol treatment. Senescence of flower was accompanied by increase in malondialdehyde (MDA) content, peroxidase (POD) activity and proline content, but, the flowers treated with 50 and 100 mg L-1 of carvacrol, thymol at 50 mg L-1 and silver nanoparticles at 5 and 10 mg L-1, the increase in the amount of MDA content, POD activity and proline level significantly was lower than the control treatments. The highest amount of anthocyanins (21.81 mg.g Fw-1) and protein content (10.45 mg.g Fw-1) in petals observed in 50 mg L-1 carvacrol. Effect of zataria oil concentrations (50 and 100 mg L-1) on physiological traits was not significant in this experiment. In general, carvacrol, thymol and silver nanoparticles used in this study were able to delay senescence in the Alstroemeria cut flowers cv. ‘Sukari’.

Oil content stability of Rosa damascena Mill was evaluated as a part of the national project executed by Research Institute of Forests and Rangelands, Iran. Thirty five Damask rose accessions from different regions were evaluated in Isfahan, Khorasan Razavi, Khouzistan, Fars, Kerman, Kurdistan and Markazi, provinces using randomized complete blocks design with three replications. Significant differences (P≤0.01) were observed between accessions, environments (year × location), locations, accession × environment and accession × location interactions. Grand mean for essential oil was 0.029%. Semnan2, Isfahan4, Semnan1, Arak1 and Balouchestan1 accessions with 0.053%, 0.045%, 0.044%, 0.044% and 0.042% respectively produced the highest essential oil content. Isfahan- with essential oil mean of 0.073% was the superior location. Results of stability analysis for accession × environment and accession × location intractions showed that Tehran1, Chaharmahal1, Yazd1 and Isfahan3 with oil content means of 0.029%, 0.028%, 0.025% and 0.027% were stable and Chaharmahal1, Qom1, Khuzistan1, Kermanshah1 and Hormozgan1 with oil content means of 0.028%, 0.028%, 0.024%, 0.023% and 0.025% were accounted as general adaptable accessions for oil production.

A group of morphological, pomological traits and fruit set percent were studied for two years in two different groups of coetaneous healthy and infected trees of ‘Jonagold’, ‘Gala’ and ‘Golden Delicious’ pruned in spindle form and grown in Horticultural Research Station and Post-harvest Laboratory of Horticulture Department under Seed and Plant Improvement Research Institute. Evaluations made on flower production per cultivar and its relative conversion coefficient to fruit in successive biological growth stages including 1 week after bloom end, June drop stage and 2 weeks before ripening time to study preservation of fruit produced demonstrated that fruit set percent and yield per tree were both higher in control than infected ones. Analysis of variances of the data regarding the traits of fruit length and fruit length/diameter ratio, stalk length, eye cavity depth, stalk cavity depth, lenticels number, TSS, TA in ‘Jonagold’; Internode number of annual branches and TA in ‘Golden Delicious’, (2010); Internode length of annual branches in ‘Gala’ (2011) were always higher in healthy trees and these differences were statistically significant for all the mentioned traits. Although a virus control certificate had already been issued to the healthy trees, ELISA test was performed randomly for TmRSV and ApMV on the relative leaf extracts, confirming the plants’ health status four years after transplantation in the experimental orchard.

In this study, the influence of fruit ripening on mesocarp oil content and fatty acid composition of kernel and mesocarp oil, grown in Tarom region of Zanjan was investigated on ‘Mari’ and ‘Shengeh’ olive cultivars. Fruits were harvested every two weeks from May to December. Mesocarp oil content was determined by dry matter using a Minispec NMR. The Kernel and mesocarp fatty acids recorded by Capillary Gas Chromatograph as well. The results showed that regardless of early and intermediate ripening of ‘Mari’ and ‘Shengeh’ cultivars respectively, oil content of mesocarp gradually increased until 150 days after full bloom. Statistically significant differences were observed for fatty acid composition among tissues, ripening stages, cultivars and their interactions. Evolution pattern of fatty acids during fruit ripening showed very different trends in mesocarp tissue of two cultivars while in the kernel it was very similar. In addition, during the ripening process, fatty acid composition in olive kernel was quantitatively and qualitatively, different from those in the mesocarp. Altogether, the results showed that the harvest time of olive fruits strongly affects mesocarp oil content and fatty acid composition of kernel and mesocarp tissues.

Drought stress is one of the most important limiting factors for plant growth and productivity. Synthesis of glycine betaine in some plants has improved the tolerance to environmental stress. In this study, the effects of glycine betaine (0, 2.5, 5, 7.5, 10 mM) and four levels watering (100% FC, 75% FC, 50% FC, and 25% FC) were investigated on two-year old Mexican lime seedlings during two months. Following treatments, lipid peroxidation, electrolyte leakage, total protein, antioxidant capacity, peroxidase and superoxide dismutase activity were evaluated. Results showed that 7.5 and 10 mM treatments of glycine betaine prevented reduction of peroxidase activity during drought stress. In addition, 10 mM treatment of glycine betaine prevented significant loss of total protein. However, glycine betaine had no effects on some traits such as lipid peroxidation, electrolyte leakage, antioxidant capacity and superoxide dismutase activity. However, 50% FC level, increased antioxidant capacity. Content of malondialdehyde was added by low watering. This study shows that, glycine betaine at different concentrations could not enhance antioxidant capacity in seedlings while has protected proteins and may antioxidant enzymes such as peroxidase. This compatible solute has probably affected drought resistance through protection of some enzymes, substitution for water release and osmoregulation.

Soil salinity is one of the major abiotic stresses that adversely affect plant productivity and quality, mainly due to excess of Cl‾ and Na+ ions in plants. Zinc induces defense mechanisms in plants against abiotic stress including salinity. A greenhouse experiment was conducted to test whether zinc is able to mitigate the deleterious effects of salt stress on growth indices in almond rootstock. The treatments consisted of NaCl (0, 30, 60 and 90 Mm) and zinc (0, 5, 10 and 20 mg kg-1soil). The layout was a 4×4 factorial experiment in a complete randomized design, with four replications and three seedlings per replication. The results showed that salt stress decreased vegetative growth parameters (shoot length, shoot and root fresh and dry weights) in almond seedlings. Application of zinc ameliorated the adverse effects of injury caused by salt stress and improved vegetative growth parameters. Salt stress reduced relative leaf chlorophyll and leaf chlorophyll fluorescence. Zinc application at 10 and 20 mg g-1 soil improved relative leaf chlorophyll and leaf chlorophyll fluorescence compared with the control. Zn+ content of leaf was not influenced by the salt stress. However, the highest rate of zinc application significantly increased Zn+ content in leaf and root of almond seedling. Zinc application increased catalase activity and ameliorated salt injury.

Most of the years, early-blooming and late spring frost can damage developing buds or flowers and reduced fruit production. In due to genetic variation, there is a wide range in time of bloom among apricot genotypes in orchards of Boein Zahra region. Therefore, the apricot germplasm of this region was evaluated to select cold tolerant and late-blooming genotypes. In this study, evaluation of traits was carried out based on descriptor list of apricot (IBPGR). In finally, in this study, 16 superior apricot genotypes selected. The genotypes showed significant differences in majority of traits, especially flowering traits. Based on cluster analyze of flowering time, superior genotypes classified in three groups of complete late flower, late flower and normal. Some studied characters were high descriptive variance. Also, between some variance observed positive or negative significant correlation coefficient.