Iranian Journal of Horticultural Science
Year:2010 | Volume:41 | Issue:4|Papers Count:10

To study the effect of nitric oxide on longevity and some qualitative characteristics of cut carnation flowers (Dianthus caryophyllus cv. Nelson), cut flowers were treated for 48 hours with Sodium Nitroprusside (SNP) as a source of NOo donor at four concentrations (0, 20, 50 and 100 mM) alone and in combination with other such ethylene inhibitors as thidiazuron and sucrose in a completely randomized design with three replication where the temperature was 20±2oC, 60–70% relative humidity, 15-20 mmol s-1m-2 light intensity and 12 hours of photoperiodism. The flowers were then transferred into distilled water. The vase life of cut flowers, their appearance, chlorophyll content, stem firmness, and water absorption rate were recorded. The results indicated that the concentration treatments of 50 and 100 mM SNP resulted in increase in vase life in comparison with control; also concentration treatment of 50 mM thidiazuron maintained the chlorophyll in leaves in contrast to control when on the 8th day after treatment. The treatment of 50 mM thidiazuron resulted in the best quality of appearance, and the treatment of 50 mM thidiazuron as well as that with 30 mM sucrose resulted in high water absorption in comparison with control. Concentration treatment of 100 mM Sodium Nitroprusside alone and treatment with 100 mM SNP in combination with 50 mM of thidiazuron on were effective stem firmness.

Most sweet cherry cultivars are as found as self-incompatible and therefore for commercial fruit production, compatible pollinizers are needed. Controlled pollination and microscopic examination of pollen tube growth in the style are two classical methods for determination of compatible and incompatible pollen donor cultivars. This experiment was carried out to explore the compatibility of ‘Zarde Daneshkadea’ as a seed parent cultivar with ‘Sefid Rezaieh’, ‘Napoleon’, ‘Abardeh’, ‘Bing’ and ‘Shabestar’ as pollen parent cultivars in using hand pollination and controlled hybridization technique. Eight samples of pollinated flowers (pistil) using different treatments were maintained and fixed in FAA solution for further microscopic examination. In order to determine the effect of pollen source on the fruit qualitative and quantitative characteristics, some fruit criteria were evaluated. According to the microscopic examination of pollen germination on the stigma and pollen tube growth within the style, pollen of ‘Shabestar’, ‘Sefid Rezaieh’ and ‘Napoleon’ cultivars very well germinated on ‘Zarde Daneshkadea’ stigma with the pollen tube getting into the ovule within 96 to 120 hours after pollination. The studied cultivars showed compatibility with ‘Zarde Daneshkadea’ cultivar. In addition, microscopic examinations showed self-incompatibility for ‘Zarde Daneshkadea’ cultivar. Therefore, ‘Zarde Daneshkadea’ is a self-incompatible cultivar and according to the obtained results ‘Shabestar’, ‘Sefid Rezaieh’ and ‘Napoleon’ cultivars are suitable polinizers. Also pollen tube growth of `Abardeh’ and ‘Bing’ cultivars stopped in the first third length of style of ‘Zarde Daneshkadea’, so showed incompatibility with this cultivar. Although, some obtained results showed differences between fruit length and width and in addition significant differences were observed in some replicates on seed weight, fruit length, fruit width and percent soluble solid contents (oBrix), but further we suggest supplemental research on the effect of pollen source on fruit quality is needed and suggested.

Embryogenic calli production in Vitis is mainly possible by use of such regenerative tissues as anther and ovary. Because of long periods of time required for obtaining such tissues, use of such vegetative organs as leaf explant would be a promising alternative. Towards this end, leaf explants were taken from two varieties of ‘Flame Seedless’ and ‘Red Sultanina’ to be raised in. MS medium, consisting of 2.5 mM 2, 4-D, 1.1 mM BAP, 1 g/l Cazein Hydrolizate, 20 g/l sucrose, and 7 gr/l of agar. After two months, calli were transferred to the same medium except for 2-4, D which was replaced by NAA. Three months after explants' culture, calli were transferred to MS medium containg varied concentrations of BAP (1, 2 & 3.5 mg/l), and IAA (2, 5 & 15 mg/l). Results showed that among different hormonal treatments, the fifth medium (BAP 5 mg/l & IAA 2 mg/l) induced a maximum embryogenesis in calli of cv. Flame Seedless.

In order to study the effects of different levels of water stress on growth and some biochemical traits of three pear genotypes (Nazkeh, Lasoreah and Kevilah), a pot experiment was established. Three pear genotype seedlings from Kurdistan province were exposed to four water supply regimes. Control seedlings were kept well watered everyday. Water stress treatments were irrigated when soil water potential reached – 0.4, -0.8 and -1.2 MPa. Plant height, stomatal density, leaf chlorophyll content (chlorophyll a, b as well as total) water were assessed following the stress period, but proline and Total Soluble Sugar (TSS) were determined both during water stress and after the plants being rewatered. The results of statistical analysis revealed that stomatal density and leaf chlorophyll contents (a, b and total) were not affected by stress treatments. Water stress exerted significant effects on growth and biochemical characteristics. Plant height decreased during water stress. Plant growth stopped in -0.8 and -1.2 treatments in Nazkeh and Lasoreh but plant height increment was 9.4% of control in Kevilah in -0.8 MPa treatment. Kevilah had a higher growth rate in -0.4 MPa treatment as compared with the other genotypes. Proline and total soluble sugars increased during water stress period but reached the control levels 2 days past rewatering in all water stress treatments. The free proline and TSS content of leaves in Kevilah genotype increased at a higher rate when in water stress conditions. The highest contents of proline and TSS were observed in Kevilah genotype in -1.2 MPa treatment. The results indicated that Kevileh genotype was more resistant to drought stress.

To evaluate the possibility of replacing natural compounds for chemical ones as antimicrobial agents in preservative solutions of cut flowers, a factorial CRD based experiment of three replications was conducted at the Department of Horticulture, Faculty of Agriculture, Tehran University. Three concentration levels of 50, 100 and 300 mgL-1 from Eugenia caryophyllata were prepared. Cut gerbera "Ecco" flowers were continuously treated with each concentration of the compound. Results indicated that longevity, fresh weight, vase solution uptake, number of bacteria in preservative solution and color change of stems were affected by essential oils and extracts. Mean longevity of treated flowers with distilled water was 3.5 days, while mean longevity of treated flowers with Eugenia caryophyllata essential oil at 300 mgL-1 was 8.4 days and mean longevity of treated flowers with Eugenia caryophyllata extract at 100 mgL-1 8.3 days. Also it was observed that all the treatments endured more longevity than control flowers. Maximum values of fresh weight were observed in Eugenia caryophyllata essential oil at 300 mgL-1 followed by Eugenia caryophyllata extract of 100 mgL-1 concentration.

Rose is considered as one of the most popular and important ornamental plants in the world. During the last decade, tissue culture, micropropagation as well as genetic engineering have prevailed in rose production industry. Gene transfer to embryogenic callus, derived from different types of explants is currently one of the most popular methods of improvement of rose cultivars, presented in particular as cut flower with such novel characteristics as blue color. An efficient tissue culture procedure covering high frequency embryogenic callus induction and plant regeneration is pre-requisite for every successful genetic engineering program. An efficient method for embryogenic callus induction from growing nodal stem segments on MS medium followed by a selection of appropriate young leaflets is hereby reported. MS medium complemented with 2 mg/L 2, 4-D, and 0.5 mg/L NAA as wekk as medium B5 complemented with 0.5 mg/L 2, 4-D and 2.5 mg/L NAA plus 0.5mg/L kinetin were used for callus induction. Cali were then subcultured in MS medium with higher levels of hormone (3 mg/L 2, 4-D and 0.5 mg/LNAA) to develop suitable size and shape embryos. This was followed by transferring the calli onto an MS medium complemented with 8 hormonal treatments. MS medium along with 1 mg/L of TDZ resulted in a highest number of embryos. High frequency of shoot development from mature somatic embryo and subsequent plant regeneration were obtained on a medium containing 3 mg/L of BAP. Shoots were rooted on MS medium supplemented with three various hormonal treatments, and there were no significant differences observed between treatments.

Some Cerasus sub-genus wild species that are used as rootstocks in sour and sweet cherry propagation can also be employed in breeding programs. The aim of this study was to clearly evaluate some characteristics of subgenus Cerasus genotypes to be used in the future cherries' breeding programs. In order to evaluate some morphological characteristics of the vegetative parts as well as seeds to categorize Cerasus sub-genus wild species and genotypes, 38 characteristics were evaluated on 28 genotypes of four species of this sub-genus collected from eight regions. The species were: P. avium L., P. mahaleb L. (Eucerasus section), P. incana Pall., and P.microcarpa Bioss. (Microcerasus section). Analysis of variance of the studied characteristics were found as significant among genotypes. Results of simple correlation analysis showed the existence of significant, positive as well as negative correlations among some such important characteristics as tree height, leaf area, as well as the length and weight of seed. Also, factor analysis showed that tree height, leaf area, leaf shape, length of petiole, length of seed, seed weight, shape of seed tip and seed thickness were characteristics that constituted the main factors. The effective characteristics became categorized within seven factors, accounting for 85.71% of total variance. Cluster analysis was performed using these seven factors and genotypes in the distance of about 25 were divided into two main groups (Microcerasus and Eucerasus) and within the distance of 19 they were divided into four groups consisting of the species. In the distance of 10 there appeared a higher number of groups (8 groups), resulting from intra-species differences of plants collected from different regions, such that genotypes of same species from one region often categorized with each other. Tri-plot analysis using three main factors could also clarify the location of genotypes and differentiate the species from each other.

Dormancy in deciduous fruit trees constitutes an important factor to be considered when selecting for the appropriate species/cultivar to be cultivated in a given geographical region. The factors influencing dormancy, however, remain poorly understood. Occurring in cold season, dormancy helps the plant with enduring adverse environmental conditions, especially chilling and freezing tensions. A sound understanding of dormancy and the contributing metabolic changes, thus, could help in selecting the appropriate species/cultivar to cope with environmental tensions. In this research, the quantitative changes in sugar compounds, starch, proline, as well as in water status in the buds of 6 apricot cultivars namely: Pish Ras Tabas and Noori Pish Ras (early-ripening), Ketabi and Shahroodi (mid-ripening), and Shahrood 51 and Shahrood 29 (late-ripening) were investigated during 2008-2009 in Golmakan Research Station, Khorasan Razavi Province, Iran. Among the cultivars, the highest dissolved sugar content (34.36 mg/g dry weight) was observed in the vegetative buds of Shahroodi 51; proving statistically different from the content in other cultivars. This cultivar was also proved to contain the highest proline content (statistically different from that in the other cultivars). No statistically significant difference was observed among cultivars with respect to water status. During the experimental run-time, the highest total carbohydrate contents were observed in October and February, respectively. The lowest water content was observed during the coldest month of the year viz. January.

Pistachio trees exhibit some such physiological problems as abscission of inflorescence buds, fruit fall, the incidence of blank, non-split, early split and deformed nuts. The occurrence of the problems would be closely related to diminishing yield. In this study, the effect of Putrescine (Put), Spermidine (Spd) and Spermine (Spm) on these shortcomings and on the yield of "Kalle-Ghooochi" pistachio was investigated in two consecutive (“on” and “off”). Free Polyamine treatments were applied one week before and two weeks after full bloom. Results showed that Spm, unlike Put, decreased the physiological shortcomings of the fruit and increased yield. Spd treatment decreased the percentage of both fruit abscission and deformed nuts, but did not affect yield. In any of the “on” and “off” years, the effect of Spm and Spd was greatly dependent on both the time of application and on the concentrations used. It seems that application of Spm dominantly plays a key role in controlling the abscission of inflorescence buds and also in improvement of growth and development of pistachio nuts resulting in increase in the yield on pistachio tree shoots.

Casing material or soil (casing) is used in mushroom (Agaricus bisporus) culture to cover a nutritional composted substrate colonised with mycelium, and has an essential function in stimulating and promoting the development of sporophores (fruit bodies). In order to use the agricultural by products (different wastes) to reduce peat consumption of casing soil in button mushroom production, an experiment was conducted in 2010 with treatments of casing soil and three replicates in a completely randomized design. Treatments consist of: 1- decomposed manure and loam soil (50%, 50%), 2- decomposed manure, spent mushroom compost and loam soil (25%, 45%, 30%), 3- decomposed manure, 4- moderate loam soil, 5- bagasse and loam soil (50%, 50%), 6- spent mushroom compost and sand (60%, 40%), 7- loam soil and sand (70%, 30%), 8- rice waste and loam soil (40%, 60%), 9- cocopeat and perlit (60%, 40%), 10- tea waste and loam soil (50%, 50%), 11- Holland peat, 12- north peat, 13- south peat, 14- spent mushroom compost and north peat (60%, 40%), 15- spent mushroom compost, 16- clay soil and north peat (65%, 35%), and 17- clay soil and sand (65%, 35%). A comparison of means with Duncan's Multiple Range Test (DNMRT) indicated that in Holland peat and north peat, mycelium could cover soil in shortest time compared to the other treatments. Results indicated that treatment of spent mushroom compost + north peat (40%, 60%) produced highest yield (2093 kg) after Holland peat. In addition, in this treatment, harvested mushroom had the highest protein content compared to other treatments. The lowest yield was obtained in loam soil + sand (70%, 30%) due to an final decrease of casing soil porosity and Water Holding Capacity. Therefore, spent mushroom compost is an alternative to reduce peat consumption in button mushroom production.