رعنا دستجردی

This study was conducted to investigate the effect of vegetative rootstocks and nutrient content on some of the most important flavonoid compounds in leaf samples of Bastam genotype (BA) and Bekran (BE) cultivar and compare them with the Red Delicious cultivar flavonoids. The experiment was conducted in a factorial way of randomized complete blocks over two years. Sampling of three-year-old trees grafted on M9 and B9 rootstocks and Bekran genotype colony rootstock was done and then the amounts of nutrients including nitrogen, phosphorus, potassium and calcium and some of the most important flavonoids including Quercetin, Kaempferol, Rutin and Luteolin in Leaf samples were measured using high performance liquid chromatography (HPLC). The results of this study showed that during two consecutive years, the amount of flavonoid compounds Quercetin, Quercetin 3-ramenoside, Luteolin, and Kaemferol were affected by rootstock and scion and their interaction. Step-by-step regression analysis showed that the amount of each element had a significant specific effect on the biosynthesis of flavonoid compounds. The total amount of flavonoid compounds in leaf samples of cultivars and genotypes grafted on M9 and Bekran colonies rootstocks increased in the second year. Also, with increasing plant age and root development, increased. The total amount of flavonoid compounds in leaf samples of cultivars and genotypes. The results of this research showed that the inherent differences between cultivars determine the amount of synthesis of secondary metabolites, but the amount of these compounds can be increased by using rootstocks that have obvious differences in vigor or are more efficient in absorbing and transporting nutrients.

Diplodia seriata is the causal agent of apple limb and trunk cankers as well as fruit black rot. Disease was detected in the Iranian apple collection located at horticultural research station of Kamal-shahr, Karaj. Fourteen apple promising genotypes and two commercial cultivars (Golden Delicious and Fuji) were tested in the field and laboratory for their relative susceptibility to the pathogen, during 2016-2017. The fruits were inoculated in the field at 2 to 3 weeks before harvest with fungal mycelia from 11-day-old cultures of PDA medium. In the laboratory, detached fruits were inoculated similarly. Genotypes were classified for susceptibility to the fungus by determining disease severity of attached fruits in the field based on lesion expansion (mm/degree-day), and on detached inoculated fruits in laboratory according to the mean lesion diameter, both 5 days after inoculation. Based on the laboratory and field data, Iranian genotypes were classified into three relative susceptibility groups: most susceptible: TR-1, SSB, and H1-SH; moderately susceptible: MD-N2, GO-N3, B-K-KH, DO-P-SH, MN8, T5 and Golden Delicious; least susceptible: SBA, MN10, S-O-G, KH2, ME6 and Fuji. There was a negative correlation between disease severity and flesh firmness, but total solid soluble (TSS) and les

Through this investigation 18 promising local apple genotypes along with Gala, Fuji, Red Delicious and Golden Delicious cultivars were evaluated for tolerance to fungal cankers in Kamalshahr horticultural research station, Karaj, Iran, during 2015 and 2016 growing seasons. Preliminary field assessment confirmed the presence of Cytospora. and Neofusicoccum in infected trees. The results showed that the relative susceptibility of genotypes to cytospora chanker was different. H1-SH and T51 genotypes with the average infection score of three were identified as susceptible, B-K-KH together with Fuji cultivar were moderately-susceptible, and SBA genotype and cv. Golden Delicious were identified as low susceptible. Artificial inoculation of Neofusicoccum isolates on dormant excised apple twigs confirmed the pathogenicity of isolates and showed different responses of genotypes to pathogen. Under field conditions, the infection score for sooty canker ranged from zero to three (in MD-N2 genotype). GO-N3, ME6, B-K-KH and SBA genotypes as well as cv. Fuji, cv. Red Delicious and cv. Golden Delicious were grouped as moderately susceptible. Simultaneous infection to both fungal cankers observed on five promising genotypes; T51, SBA, S-O-G, H1-SH and B-K-KH, as well as cv. Golden Delicious and cv. Fuji. It can be concluded that there are invaluable resistance sources among promising local apple genotypes, under natural infection, to be selected and used in apple breeding programs.

In this study survivability, morphological characteristics and pathogenicity of 12 isolates of Ophiognomonia leptostyla, which is known as causal agent of walnut anthracnose, have been evaluated after 13-years of storage on filter paper in oat meal agar (OMA) and -20°C. The recovery rate varied from 0 to 89 percent and seventy-five percent of stored isolates were shown to be viable. In macroscopic and microscopic studies of revived cultures, the morphology of colonies was uniform for all isolates. Production of asexual bodies (acervular conidiomata) was preserved by all isolates. Fertile perithecia with asci and ascospores were not detected in pure fungal cultures after three months incubation at 8-10°C in darkness. In pathogenicity experiments, there was not a significant variability in infection severity for different isolates, and the first symptoms were observed on leaves 12-16 days after inoculation. Stability of morphological characteristics, ability to sporulation and retaining the pathogenicity of isolates confirmed that transferring of acervuli on filter paper in OMA medium could be a suitable, safe, simple and cost-effective tool to preserve O. leptostyla isolates in a viable state.

Neofusicoccum mangiferae is the causal agent of branch wilt, blossom blight, canker and dieback on a variety of fruit trees such as almond, hazelnut, apricot, peach, citrus, grape and apple. Cracking and peeling of thin outer layer of bark and exposing black sooty mass of spores is a characteristic feature of disease. Pathogen causes gradual declining and sometimes complete death of trees. The fungus infects the hosts through wounds, created by pruning, frost damage, drought stress, or bark cracks caused by sunburn and develops under hot and sunny weather in summer. Good sanitation, fertilization of trees, adequate irrigation, appropriate pest control, preventing wounds, and avoiding unnecessary pruning are the methods for disease management.

In order to study fruit quality changes in apple cultivar Gala, related to ripening stage and storage time, an experiment was conducted in a split plot arrangement in Randomized Complete Block Design with four replicationsin the area of Damavand– Jaban for three years. Five levels of sampling times in storage were assigned to main plots, and three levels of harvesting times were randomized in sub plots. Flowering time was recorded for six selected trees. Fruit was harvested during ripening process, every week, based on the starch index (1-5). The samples were tested for total soluble solids content (TSS), titratable acidity (TA), weight decrease, fruit firmness, flavor and acceptability. Harvested fruits were stored in storage under 0 ± 1°C temperature and 85 ± 5% relative humidity, for five months. The optimal fruit quality was achieved when the fruits harvested in 110 days after full-blooming with 2.0-2.5 starch index.

Most of walnut production in Iran comes from seed originated trees with low quality and quantity as product. For breeding new cultivar(s), from 1983 selection of Iranian walnut germplasm was started at Seed and Plant Improvement Institute and at the first phase 117 genotypes were collected. Seedlings of these genotypes were planted in Kamalshahr (Karaj), Torogh, Kahriz and Bastam Horticultural Research Stations and evaluations were done for five years. In Karaj, genotype Z63 was selected together with six other promising genotypes. These seven genotypes and eight foreign walnut cultivars were evaluated for 15 years. Results showed that Z63 was the best among the native selected promising genotypes. The tree has medium vigor, spreading habit, low shoot density and early- medium leafing time. Z63 is a protandrous genotype, so for commercial production it needs a pollinizer cultivar. Pistillate flowering period was medium and the pollen shading period was early. Fruit and kernel weight and kernel percent was 11.41 g, 5.8 g and 50.77 %, respectively. The minimum planting distance for this genotype is about 7×7m and its yield varied from 500 kg in 5th year to 4 tha-1 at the maturity. Fruit shape is long elliptic with smooth shell texture. It has relatively low susceptibility to winter frosts and chilling requirements of terminal and lateral buds and catkins were estimated 750, 900 and 650 hours. Growth degree hour (GDH) of terminal and lateral buds and catkins were 14636,15186 and 9071 respectively. Pistillate flower abscission (PFA) of this genotype showed to be very low. Susceptibility to anthracnose (Gnomonia leptostyla) was also very low. The leaves of this genotype was susceptible to bacterial blight (Xanthomonas compestris), but after infection most of leaves abscised that helps to reject the infection. Unriped fruits of this genotype had the highest resistance among the evaluated cultivars and genotypes. Long term evaluation of this genotype together with other native promising and foreign cultivars led to officially introduction of this genotype as the first and a new walnut cultivar in Iran in 2010 and named Jamal by Cultivar Release Committee of Agricultural Research, Education and Extension Organization.

Most of walnut production in Iran comes from seed originated trees with low quality and quantity as product. For breeding new cultivar(s), from 1983 selection of Iranian walnut germplasm was started at Seed and Plant Improvement Institute and at the first phase 117 genotypes were collected. Seedlings of these genotypes were planted in Kamalshahr (Karaj), Torogh, Kahriz and Bastam Horticultural Research Stations and evaluations were done for five years. In Karaj, genotype Z63 was selected together with six other promising genotypes. These seven genotypes and eight foreign walnut cultivars were evaluated for 15 years. Results showed that Z63 was the best among the native selected promising genotypes. The tree has medium vigor, spreading habit, low shoot density and early- medium leafing time. Z63 is a protandrous genotype, so for commercial production it needs a pollinizer cultivar. Pistillate flowering period was medium and the pollen shading period was early. Fruit and kernel weight and kernel percent was 11.41 g, 5.8 g and 50.77 %, respectively. The minimum planting distance for this genotype is about 7×7m and its yield varied from 500 kg in 5th year to 4 tha-1 at the maturity. Fruit shape is long elliptic with smooth shell texture. It has relatively low susceptibility to winter frosts and chilling requirements of terminal and lateral buds and catkins were estimated 750, 900 and 650 hours. Growth degree hour (GDH) of terminal and lateral buds and catkins were 14636,15186 and 9071 respectively. Pistillate flower abscission (PFA) of this genotype showed to be very low. Susceptibility to anthracnose (Gnomonia leptostyla) was also very low. The leaves of this genotype was susceptible to bacterial blight (Xanthomonas compestris), but after infection most of leaves abscised that helps to reject the infection. Unriped fruits of this genotype had the highest resistance among the evaluated cultivars and genotypes. Long term evaluation of this genotype together with other native promising and foreign cultivars led to officially introduction of this genotype as the first and a new walnut cultivar in Iran in 2010 and named Jamal by Cultivar Release Committee of Agricultural Research, Education and Extension Organization.

An experiment was conducted to evaluate relative resistance to P. cactorum, the casual agent of apple crown rot, in eleven apple rootstocks. The experiment was in factorial (with apple rootstocks and year factors) on the basis of completely randomized design with three replications. Each plot consisted of four young plants. All rootstocks excluding Morabbaei, were propagated vegetatively. One year old rootstocks were evaluated in pots containing soil inoculated artificially with inoculum of P. cactorum. Disease response of the rootstocks was assessed three months after inoculation based on canker length (cm), crown girdling (%), mortality (%) and mean canker area (cm2). The analysis of variance on pooled data showed that effect of rootstock on measured characterestics was significant at 1% probability level. MM106 rootstock was highly susceptible (mean canker area: 4.72 cm2, crown girdling: 89.33%, canker length: 5.28cm and mortality (%): 83.33%). M9, Azayesh and CK1 rootstocks were resistant and Morabbaei and MM111 rootstocks were moderately susceptible compared to the highly susceptible rootstock.. Gami almasi and CK2 rootstocks were moderately resistant and M26, M27 and B9 rootstocks showed relatively tolerance responces to P. cactorum. Interaction between year and rootstock was not significant.

Anthracnose, caused by Gnomonia leptostyla, Anamorph: Marssonina juglandis (Lib.) Magn.), is the most serious disease of walnut. The present study was designed to determine relative resistance to the disease in eleven walnut genotypes using a factoriel experiment on the basis of completely randomized design. After grafting of walnut genotypes, grafted plants were inoculated by a 105 spore per ml suspension of the pathogen. The results showed that germination of spores was higher on the upper surface of the leaves. The first symptoms of infection appeared on Z60 and Hartley four days after inoculation. The acervuli were produced first on K72 genotype about 27 days after inoculation. Two months after inoculation, evaluation was done in each plants by determination of the number and the mean diameter of spots and leaf infection percent. The results showed that there were significant differences among the genotypes in number and size of spots. The highst leaf infection percent occurred on Z60, K72 and Hartley, and Vina and Ronde de montignac showed the least leaf infection percent

This study was carried out to identify Fusarium species associated with sugar beet root rot and yellows. Pathogenicity of Fusarium oxysporum, the causal agent of Fusarium yellows of sugar beet was also investigated. Samples of infected roots were collected from fields in major sugar beet producing areas in Khorasan province during 1999-2000. Infected roots were washed, surface sterilised and plated on PDA. One hundred sixty eight isolates of Fusarium spp. were recovered. Seven species were identified including Fusarium solani (42 isolates), F. oxysporum (31 isolates), F. acuminatum (27 isolates), F. avenaceum (23 isolates), F. moniliforme (19 isolates), F. equiseti (16 isolates) and F. culmorum (10 isolates). All isolates of F. oxysporum were tested for their pathogenicity on seedlings and matured sugar beet plants. The results showed that 12 isolates (38.7%) of F. oxysporum were non-pathogenic, and 19 isolates (61.3%) were pathogenic.