Iranian Journal of Horticultural Science and Technology
Year:2010 | Volume:11 | Issue:1|Papers Count:9

In recent decade, interspecific hybrids are used as clonal rootstocks especially in prunus genus for stone fruit trees. In this research, rooting potential of 'HS314', 'HS312' (Prunus amygdalus ´ P. persica) 'HS302', 'HS304' (P. armeniaca ´ P. cerasifera) and 'GF677' were evaluated in modified MS and WPM (half of macro elements) culture media, supplemented with IBA (0, 0.5, 1, 1.5 and 2 mg 1-1). In another experiment, rooting of genotypes were studied by dipping of shoots base in IBA solution (0, 500, 750 and 1000 mg 1-1) for 5 seconds. After treatment, all of the specimens were kept in dark room for 7 days and then transferred to a growth chamber. The results showed that Prunus amygdalus ´ P. persica hybrids in modified MS and P. armeniaca ´ P. cerasifera hybrids in WPM with 1.5 and 2 mg 1-1 IBA + 7 day darkness had 65-70% rooting, respectively. In dipping of the microcutting base, high success of rooting percentages (75-80%) was obtained with 750 mg 1-1 IBA concentration. The means comparison showed that 'HS314' and 'HS302' had higher percentage of rooting, root number and length of roots than other genotypes. Rooted shoots were transferred to the pots, containing a mixture of peat and perlite in the ratio of 1: 1 (v/v) and were kept in a greenhouse. Rooted plantlets were successfully acclimatized with 75% of plants survival.

This experiment was carried out to investigate the effects of bulb harvesting time, indolebutyric acid (IBA) concentrations and changes of soluble carbohydrates on bulblet number, weight and diameters on scale propagation of L. ledebourii (Baker) Boiss cv. 'Chelcheragh'. Treatments consisted of bulb harvesting times from natural habitat, Damash in Gillan province (0, 50, 100 and 150 days after flowering) and lBA concentrations (0, 300 and 600 ppm) and also effects of scale positions (mother and daughter scales) in mentioned bulb harvesting dates on sucrose, fructose and glucose soluble carbohydrates. Results showed that lBA concentration on regenerated bulblet numbers and diameters was significant at 5% and 1% level of probability, respectively. Bulb harvesting time had not significant effects on bulblet characteristics. Effect of lBA concentration on bulblet characteristics showed that although 300 ppm lBA had greater means than other concentrations, in camparison with other concentrations did not show any significant differences. Bulb harvesting times and lBA concentrations showed significant differences at 5% and 1 % level, respectively, on bulblet number and diameter. Greater number of bulblets obtained in bulbs that were harvested in 100 days after flowering and treated with 300 ppm IBA. Effects of scale positions and bulb harvesting times on soluble carbohydrates concentrations showed that mother scales had greater carbohydrates than daughter scales. Greater amount of sucrose, fructose and glucose were in bulbs that harvested 50 days after flowering.

Nowadays, the use of chemicals for controlling postharvest diseases and extending of storability of horticultural products have been restricted due to environmental concerns. Therefore, in the present study, we used UV-C as a recommended method at different doses (0, 0.5, 1.5, 3, 4.5 and 9Kj m-2) for controlling of fungal rots and maintaining postharvest quality of tomato fruits. The results showed that fungal decay decreased significantly by UV -C treatment at 3, 4.5 and 9 Kj m-2 in comparison with control. UV-C treatments did not have any significant effect on the pH, T A, TSS and vitamin C, but 35 days after treatment, UV-C treated fruits showed low ripening index in comparison to control (TSS/TA=8.4) and among the UV-C treatments, 9 Kj m-2 had the maximum ripening index (TSS/TA=6.35). UV -C light had not significant effect according to the Hue angle but L* index was maintained at primary level. The most and least weight losses observed in 0.5 Kj m-2 (9.7%) and 9 Kj m-2 (3.2%) UV-C treatments, respectively.

Fifteen isolates of Pseudomonas fluorescens were evaluated as potential biocontrol agents for blue mold caused by Penicillium expansum in vitro and in vivo. Dual culture, cell free metabolite and volatile tests showed that all 15 isolates of Pseudomonas fluoresces inhibited growth of P. expansum. Inhibition varied from 36 to 80% in dual culture; 37 to 90% in cell free metabolite and 37-87% in the volatile tests. In storage experiments inoculated apples were incubated at 20oC and 5oC for 12 and 45 days respectively AIl bacterial isolates had significant preventive effect against P. expansum on wounded apple fruit compared to pathogen control and the isolate F7 was the most effective isolate for control of apple blue mold at both temperatures. The CFU/gram wound tissue in isolate F7 of P. fluoresces Were determined during experiment. The population of this bacterial isolate in treatment pathogen antagonist was decreased but population of P, fluoresces increased when apple inoculated with bacterial cells alone.

In order to increase water use efficiency and drought resistant olive cultivars selection for development of olive cultivation in arid and semi-arid regions of Iran, an experiment was conducted to evaluate the growth and physiological responses of six Iranian native olive cultivars (‘Zard', 'Roghani', 'Mary', 'Fishmi', 'Dezful' and 'Shenge') under drought stress. Two-year-old olive plants were assessed in a split plot design based on complete randomized block design. Some characteristics such as stomata resistance and proline level were measured under drought stress. For irrigation treatments, two-, six- and twelve-day treatments were selected and the two-day treatment was held for control. Results revealed that increase in irrigation intervals and drought stress degree had significant effects on stomata resistance, leaf water potential and proline level. Conspicuously, leaf proline level increased with increase in drought stress degree and this was seen in all cultivars of this study. The consequence with increase in irrigation intervals was improvemerit in stomata resistance and maximum stomata resistance was seen in 'Dezfuli' and 'Mary' cultivars. Results also showed that in all cultivars, leaf water potential decreased with higher drought stress and 'Mary' and 'Dezfuli' cultivars had minimum leaf water potential. There were significant differences among cultivars in stomata resistance and leaf water potential traits but there was not any significant difference in leaf proline level trait. Results indicated that among cultivars used in this study, 'Dezfuli' and 'Mary' cultivars were resistant and 'Roghani' cultivar was susceptible to drought.

To study the association of flower yield with plant characters an experiment was conducted to evaluate 40 accessions of Damask rose, using a randomized complete block design with 3 replications in Research Institute of Forests and Rangelands, Tehran, Iran. Accessions showed significant differences for different traits. The estimated heritability was high (50-96%) for most of the traits, including flower yield, bloom number, flower number, flower weight, start of bud growth, leaf fall, plant height, leaflet length and stipule width. Significant positive genetic correlations were obtained between flower yield and various characteristics including flower number, bloom number, plant height, canopy diameter, stipule length and width. The results of stepwise-regression analysis indicated that the maximum variation in flower yield could be attributed to the flower number and flower weight. Based on path analysis results, bloom number, flower number and plant height, showed positive direct effects on flower yield. Thus, these traits may be used as selection criteria in breeding programs to improve flower yield.

Iris is one of the most important cut flowers in Iran and around the world. Number of choromosomes of Iranian Iris, varies between 2n=2x=18 to 48. Identification of genetical potentials of Iris germplasm in Iran and their uses in creation of new cultivars, is the main aim of Iris breeding. Genetic diversity of 18 Iris species collected from different parts of Iran was studied using 15 quantitative and 30 qualitative traits that were evaluated on the basis of UPOV guidelines. The experiment was carried out at Research Station of Ornamental Plant Center at Mahalat in 2009. Statistical methods including correlation coefficients, means, principle component analysis (PCA), and cluster analysis by UPGMA algorithm were applied for the quantitative traits. Qualitative characters were also used for species grouping according to cluster analysis. The results showed that genetic variations among different species with considering various characters. Inner tepal length with inner tepal width, branch flowering thikness with crown thikness and crown thikness with leaf width had the highest positive significant correlations and the perianth tube length with pistil width of bridge had the lowest negative correlation. Meanwhile, I. germanica, I. iberica, I. paradoxa and I. spuria almost had the highest quantitative traits. Results of principle component analysis showed that 77.39% of total variations were defiened by four components. Cluster analysis based on quantitative traits, divided all species into two main groups. One group was tall irises with rhizomatous type which grows naturally under humid conditions and second group was short irises having rhizomatous or bulb and was usually found under dry conditions. Cluster analysis based on qualitative traits, divided all irises in to two main groups varying in flower color, bud flower color, and perfume. No relationship was found between genetic diversity and geographical classification.