IRANIAN JOURNAL OF HORTICULTURAL SCIENCE AND TECHNOLOGY
Year:2002 | Volume:3 | Issue:1-2|Papers Count:7

The effects of salinity on growth characteristics and amount of minerals content of seedlings of four almond cultivars ('Azar', Sahand', Shkoofeh' and 'Non Pareil') were studied using a randomized complete block design with five replications. After stratification, the seeds were planted in pots containing perlite and then were cultured under greenhouse conditions. After one month. Seedlings were kept under salinity stress with 0.50 and 100Mm NaCl At the end of salinity treatments, final length of stem. leaf area, total dry and fresh weight of plant, dry and fresh weight of shoot and root, and Na, Ca. K. Mg and Cl contents in stem were measured. The results showed that the salinity stress reduced the stem length. Leaf area total dry and fresh weight of plant and dry and fresh shoot weight in all cultivars according the NaCl levels. So that most reduction in growth characteristics was with 100mM NaCl. Salinity levels increased stem Na and Cl contents and Na/K ratio in all cultivars. But had no effects on Ca, K and Mg contents. Sahand' had low Na and high K contents in comparison with others and had also lower Na/K ratio. The studied cultivars did not significantly affected Cl, K and Ca contents in stem but not Mg. 'Non Pareil' had a more stem Mg content in comparison with others.

Forty wild almond trees were sampled and studied using morphological traits and protein markers in each of the following areas in Isfahan province: Pashandegan, Mahorestan, Vanak. 1-Kashan Naien and 2-Kashan in 2001. Morphological traits were included leaf length. leaf width, petiole length. leaf area. shell and kernel dimensions and shell and kernel weight. The variability of seed storage proteins were analyzed electrophoretically and eight bands were observed, attributed to four loci: A (two alleles), B (three alleles), C (two alleles) and D (as a complex locus). Three species of Amygdalus haussknechtii (Pashandegan, Mahorestan and Vanak populations), A. scoparia (1-Kashan and Naien populations) and A.lycioides (2-Kashan population) were detected. Cluster analysis based on squared Euclidean distance in morphological traits and Nei genetic distance in protein markers related to SDSPAGE using UPGMA method indicated the same and clear grouping. Thus, protein markers can be used even more efficiently instead of evaluation of morphological traits which is more cost and time consuming.

Iron chlorosis is one of the important limiting factors for production of strawberry (Fragaria ananassa Duch.) in calcareous soils. Low solubility of Fe compounds in soil is usually the cause of chlorosis. Sulfuric acid (H2SO4) has been applied to such soils in order to correct the chlorosis of field crops but research reports for horticultural crops is scarce. This study was, therefore conducted to investigate the effect of H2SO4 application on growth and Fe uptake of strawberry' Armore' grown on a calcareous soil. The experiment was a 4´4 factorial with complete randomized design with 4 rates of H2SO4 (0, 10, 20 and 30 g of H2SO4 kg-1 soil) and 4 rates of Fe (0, 5, 10 and 15mg Fe kg-1 soil as Fe-EDDHA) in four replications. Vegetative and reproductive growth, pH and also electrical conductivity (EC) of treated soil were studied. Soil pH decreased and EC increased as the rate of H2SO4 application increased. The effect of H2S04 and Fe on the weight of the secondary fruits was more pronounced. Application of H2SO4 up to 20g kg-1 soil, increased the weight of the primary fruit but the weight decreased at the higher rates of H2SO4 presumably due to increase in soil EC. The highest weight of the primary and secondary fruit and total yield per plant were obtained at 30g H2SO4 plus 10mg Fe kg-1 soil. This is beleivcd to be due to the effect of Fe which alleviated the suppressing effect of high EC. Application of 15mg Fe kg-1 soil, however, did not prevent the suppressing effect of high EC. This may be attributed to the antagonistic effect of Fe on other nutrients. Application of H2SO4 increased leaf area and chlorophyll content of the leaves. The highest chlorophyll content was obtained at 20g H2SO4 kg-1 soil. Decrease in leaf area and occurrence of observed at higher rates of H2SO4 leaf scorching due to high EC were observed at higher rates of H2SO4.

To identify and determine susceptibility and resistance of some commercial cultivars of Vitis vinifera and interspecific hybrids of Vilis to crown gall, 3 years experiments were conducted. Twenty commercial cultivars of grapevines and 6 interspecific hybrids were compared against inoculation with Agrobacterium vitis (isolated from grapevine sap and cultured on modified RS media). The nursery soil was contaminated with the bacterial suspension (5×108 cfu ml-1 10kg-1 nursery soil). After root regeneration, cuttings were inoculated to the bacterium crown gall agent by injection of bacterial suspension (5×108 cfu ml-1) (1ml in 2nd internodes of green stem). Also, speared with sterile toothpick on to stem at the end of 3rd year, the percentage of infected plants were recorded. Results showed that all studied European grapevine cultivars were susceptible or very susceptible, but hybrids showed strong or good resistance behavior, specially hybrids 4 and 6.

An experiment was conducted in 2001 in east of Maragheh region to study the effects of time of application of carbaryl and urea on fruit thinning in 'Golden Delicious' apple. The factorial experiment was arranged in randomized complete block design with two replications. Experimental factors included: time of chemical application (5 and 25 after full bloom), carbaryl at 0, 300 and 600 mg 1-1 and urea at 0.2, 4 and 6%. Some criteria such as percent of fruit thinning, fruit weight length and diameter, fruit length/diameter ratio total soluble solids. russeting and damage rate of shoots were analyzed. The results showed that the effect of carbaryl on percent of fruit thinning was very significant (P<0.01). The highest level of thinning obtained from 600mg 1-1 carbaryl. The effects of urea concentration on weight, length and diameter of fruit and percentage of fruit thinning was significant (P<0.05). The highest weight and length/diameter of fruit obtained from 2% and highest fruit thinning with 6% urea. The interaction of urea concentration and time of application on shoots damage was very significant (P<0.01). The highest damage to the shoots was observed with 4 and 6% urea that applied 5 d after full bloom. Regarding these results and considering environmental pollution with carbaryl application and harmful effect against pollinator insects, urea application at 2% in 25 d after full bloom for fruit thinning of 'Golden Delicious' apple is recommended.

Citrus production in Iran exceeds 3.5 million tons per year. Any reduction in fruit losses will be of great interest to citrus growers. An experiment was conducted using naphthalene acetic acid (NAA) at the concentrations of 0, 300, 400 and 500 mg l1 and 2,4-dichlorophenoxyacetic acid (2,4-D) at the concentrations of 0, 10, 30 and 60 mg l1  on Satsuma mandarin (Citrus unshiu) to evaluate their effects on peel firmness, fruit preharvest drop and relative frequency of different sizes of fruits. The results indicated that all concentrations of 2,4-D and 400 mg l-1 NAA increased peel firmness. Preharvest drop was significantly reduced with 400 mg l-1 NAA. In all treatments of NAA and 2,4-D. the number of very small or unmarketable fruits was significantly reduced.

Several experiments were conducted for selecting the optimum callus induction and growth conditions in three miniature rose cultivars ('Little Buckaroo', 'Baby Masquerade' and Sourati'). In preliminary experiments, leaflet explants were found the best among different explants and were cultured on MS medium supplemented with benzyladenine (BA) and indoleacetic acid (IAA) or indolebutyric acid (IBA) or naphthaleneacetic acid (NAA). Explants that were cultured on MS medium supplemented with 0.5 mg l-1 BA and 2 mg l-1 NAA, had the best callus production in establishment and further subculture media. Forthy days after the first subculture, 'Baby Masquerade' and' Sourati', had the highest and lowest callus growth, respectively. Different treatments such as using casein hydrolysate, yeast extract, red light and changing the light intensity were applied which were unsuccessful for shoot and/or root regeneration in calli.