مجله علوم و فنون باغبانی ایران
سال بیست و دوم شماره 2 (تابستان 1400)

The alternate bearing, severe fluctuation in annual fruit yield, causes a type of abiotic stress in olive trees during ON-year, i.e. the year with high fruit load. Hence, one could assume a hypothesis in variation of leaves antioxidant capacity in this regard. The current study was conducted aimed at assaying this hypothesis through analyzing some antioxidant enzymes activities and their gene expression patterns. For this, leaves samples were collected from 12-year-old olive (cv. Conservalia) trees, both ON- and OFF-type, at flower bud induction phase during two successive years. Among studied criteria such as antioxidant capacity, phenol, flavonoid and total protein contents, the amount of phenol in OFF-trees was substantially higher than ON-trees. The activity of peroxidase (POD), superoxide dismutase (SOD) and phenylalanine ammonia-lyase (PAL) was considerably influenced by bearing status. In comparison to OFF-trees, the activity of the POD enzyme was higher in ON-trees, and the opposite trend was revealed in terms of SOD and PAL activities. The relative gene(s) expression of POD and polyphenol oxidase (PPO) in ON-trees, and SOD and PAL in OFF-trees was significantly high. While the SOD showed downward trends, the POD witnessed an upward pattern in terms of its activity and gene(s) expression profile in ON-trees. In general, the phenolic compounds synthesis and their consumption are the dominant metabolic process in OFF- and ON-trees, respectively.

In order to determine the most appropriate intercropping pattern of pot marigold (Calendula officinalis L.) and lavender (Lavandula angustifolia L.), an experiment was conducted as completely randomized block design with three replications during 2017-2018 cropping season. Intercropping treatments included: different intercropping ratios of calendula and lavender (100% calendula:  calendula sole crop, 75% calendula: 25% lavender, 50% calendula: 50% Lavender, 25% calendula flower: 75% lavender, and 100% lavender: evergreen sole crop). The measured traits included plant height, fresh and dry weight of shoot, leaf chlorophyll, essential oil percentage and Land Equivalent Ratio (LER) index. The results showed that the highest plant height (64.54 and 51.56 cm), shoot dry weight (820.17 and 139.67 g m-2), and flower yield (661 and 4.29 g m-2) were observed in sole culture of pot marigold and lavender, respectively. The number of branches and the percentage of essential oil for both crops under intercropping treatments were higher than sole culture. The land equivalent ratio (LER) in all intercropping treatments except 25% pot marigold and 75% lavender was higher than one and between 1.4 and 1.75. In general, intercropping of pot marigold with lavender as 50%:50% is recommended higher efficiency and production stability.

In order to investigate the effects of different rootstocks on vegetative growth parameters and the control of mineral elements of sweet lime scion under the calcareous soil conditions, an experiment was conducted. This experiment was designed in a completely randomized design with 4 replicates and 10 citrus rootstocks under nursery conditions. Based on the results, the greatest scion length and dry weight were recorded on sweet lime (37.5 cm and 19.7 g, respectively) and Volkamer lemon (33.9 cm and 19.1 g, respectively) rootstocks and the highest root fresh and dry weight was observed using Bakraei rootstock (39.0 and 11.6 g). The scion had the highest contents of nitrogen on Kara mandarin rootstock (3.17%); potassium, zinc and manganese on Volkamer lemon rootstock (2.68%, 88.5 and 36.0 mg kg-1); calcium on Lisbon lemon rootstock (4.9%); magnesium on Clementine rootstock (1.1%); iron on local sweet orange rootstock (126 mg kg-1) and copper on Mexican lime rootstock (20.5 mg kg-1). The lowest contents of boron was detected by using Bakraei, sour orange, Mexican lime, sweet lime and Volkamer lemon rootstocks. The least sodium was recorded by using grapefruit, Kara mandarin and Volkamer lemon rootstocks. Finally, comparative advantage of the rootstocks to creat graft combinations with sweet lime was determined. The highest scores were assigned to Volkamer lemon, sweet lime and Bakraei rootstocks, respectively; and local sweet orange, Kara mandarin, Lisbon lemon, Clementine and grapefruit rootstocks had the lowest scores, respectively. Mexican lime and sour orange rootstocks were considered as intermediate rootstocks.

In this research, 16 local and 4 imported lines were evaluated using morphological and phonological characteristics via lettuce descriptor in a completely randomized design block with 3 replicates at University of Guilan. Results indicated that there is a high variability in local lettuce lines. Imported lines, in comparison to local lines, had significant differences in the most evaluated traits. These differences could be considered in breeding. According to flowering time, evaluated lettuce lines ranked in three groups, including early, moderate and late flowering. Head weight ranged from 906.33 g (line 84-96-TN) to 284.33 g (line Sheikh-Aboud) and their differences were significant at P≤0.01. There are high genetically variations between lettuce lines. The differences between lettuce lines were significant for quantitative traits. Cluster analysis based on quantitative and qualitative characteristics was conducted separately. Evaluated lines were ranked into 3 groups based on quantitative and qualitative characteristics. Differences in cluster analysis between quantitative and qualitative traits were observed. These differences could be considered in crosses, breeding works, and hybrid seed production with different characteristics.

In this study, the effects of fertigation with different levels of nitrogen (200, 400 and 600 g/tree and the ratio of nitrogen, phosphorus and potassium was 4: 1: 3) and hole method fertilization on flowering, fruit yield, oil yeild and quality of olive cultivar Zard were investigated during two consecutive years. The results showed that fertigation treatments significantly increased inflorescences and flowers number, fruit and oil yield. The highest number of inflorescences and flowers were found with 400 g nitrogen as compared to the control and hole method fertilization in the first year. The highest fruit yield (35.2 kg/tree) was found with 400 g nitrogen in the first year and 400g and 600g nitrogen about 44.65 kg/tree in the second year. The highest oil yield (4.5 kg/tree) was found with 400 g nitrogen in the first year and 600 (8 kg/tree) and 400 (7.2 kg/tree) g nitrogen in the second year, respectively. No significant differences were found between fertigation treatments and hole method fertilization and control for oil peroxide value, free fatty acids, K232. The highest leaf nitrogen and potassium contents were found in hole metod fertilization and fertigation with  200 g nitrogen, respectively. Overall, fertigation with 400 g/tree nitrogen could increase fruit and oil yeild in olive cultivar Zard withoud undiserable effects on oil qualiy.

The aim of this study was to evaluate the potential effects of biological fertilizer (BF) and biochar (BC) application on flowering and morphophysiological charachteristics of Narcissus. A factorial experiment based on a completely randomized design was conducted in12 treatments with three replications. The BC was applied by mixing dry soil at three levels (0, 2 and 4%w/w), whereas the BF was used at four levels (0, 20and 40 g Kg-1  mycorrhizal fungi(MF) and Nitrozist biofertilizer). The MF was used in direct contact with the underside of bulbs and bulbs were dipped in Nitrozist biofertilizer solution for 5 minutes. According to the results the highest fresh weight of flower, number of flowers, flower diameter, flowering stem diameter, height, leaf fresh weight, chlorophyll a, b and total leaf and potassium uptake were obtained in the combined treatment of 2%biochar by 40 g Kg-1 MF. Generally, in the most of studied traits, alone use of BF and BC improved the growth and flowering characteristics of plant compared to the control. However, the best results were obtained in the combined treatment of 2%BC and 40 g Kg-1 of MF, while by increasing the levels of BC and BF in combination with 4%BC and BF the desiered results were not obtained.

This research was carried out in three separate experiments based on a randomized complete block design with four replications. In the first experiment, GA3 (0, 10, 20, and 30 mg L-1) was sprayed 10 days befor flowering. The second experiment, consisted of four levels of defoliation including; non-defoliation (control), defoliation of two nodes below the frutful branches, defoliation of four nodes below the frutful branches and defoliation of six nodes below the frutful branches one weeks before the stage of full bloom . The third experiment consists of four levels of cluster thinning including; no thinning (control), removal of 1 cm from the cluster end, 2 cm  from the cluster end and brushing of the clusters before the stage of full bloom. Comparison of the three experiments in term of cluster compactness showed mean cluster compactness of 5.6, 6.3 and 6.8 by application of GA3, defoliation and cluster thinning, respectively. The results showed that, the defoliation of the six nodes below the frutful branches and brushing of the cluster could decrease the cluster compression while GA3 significantly increase the length of the main and sub axes of the cluster and decrease the number of berries. Finally, it is recommended to use 30 mg L-1 GA3 10 days before flowering to reduce the cluster compactness.

Olive consumption has been steadily increasing in recent years, due to the increase in consumption, attention to quality has become very important, so that researchers in various ways seek to maintain and improve the quality of the product of this plant. This experiment was designed and performed to investigate the effect of glycine betaine and salicylic acid on photosynthetic properties, macro elements, compounds in Leaf and fruit characteristics of three olive cultivars in a factorial experiment with three factors glycine betaine (water, 10 and 20 mM) and salicylic acid (water, 3 and 6 mM) and cultivars (Arbequina, Koroneiki and Conservolia). During this study were evaluated the flower characteristics, inflorescence, initial and final fruit formation percentage, fruit characteristics, Compounds in Leaf, photosynthesis, transpiration, chlorophyll and gas exchange. Proved the effect of glycine betaine, salicylic acid and cultivar on leaf elements and compounds was significant and the highest amount of total phenol observed in Koroneiki cultivar and 10 mM glycine betaine and 3 mM salicylic acid treatment. In the study of the effect of treatments on photosynthesis, transpiration, chlorophyll and gas exchange of leaves, it found that 20 mM glycine betaine treatment without salicylic acid and 10 mM glycine betaine combined with 6 mM salicylic acid had a positive effect on photosynthesis and water use efficiency. Finally, this study confirmed the increasing effects of glycine betaine and salicylic acid on indices such as leaf phenol, photosynthesis and water use efficiency under stress-free conditions.

Identifying land potential and suitability based on soil characteristics is one of the appropriate management tools to increase sustainable land use. The objective of this study was to investigate the effect of soil characteristics on fig yield, their rating and the preparation of vegetative requirements table of this plant for land suitability studies by FAO method. Therefore, 94 fig orchards were selected in Fars, Lorestan, Kermanshah and Kerman provinces. In each orchard, a soil profile was studied, a land use questionnaire completed and physical and chemical tests performed on soil samples. The values of soil characteristics were calculated by applying weighting factors with depth in the profiles and multivariate regression between yield and soil characteristics was investigated by stepwise method. The high coefficient of determination of the multivariate model (R2= 0.89, P<0.01) showed that the variables entered in the model were able to determine 89% of the variance related. The results showed that among the measured soil characteristics, the effect of salinity, alkalinity, amount of lime, gypsum, gravel, available phosphorus and potassium was significant on fig yield. Finally, according to the results, soil salinity, alkalinity, amount of gypsum, lime and gravel had a decreasing effect and organic carbon, available phosphorus and potassium had an increasing effect on fig yield.

African violet is a commercial ornamental plant with various colors. For direct regeneration, in the first experiment, the effect of leaf, node, petiole, root, petal and sepal explants of four African violet cultivars were evaluated on MS medium containing different concentrations of NAA+BAP and IBA+BAP hormones, which was performed as a factorial in a completely randomized design. In the second experiment, the tolerance threshold of leaf and petiole explants to Hygromycin and Kanamycin antibiotics was evaluated by culturing on selective media supplemented with different concentrations of given antibiotics. After determining the suitable concentrations of the antibiotics for selective medium, the transformation of AS1 and 4'CGT genes was conducted with Agrobacterium LBA4404 strain containing pCAMBIA1304 and pBI121 plasmids, respectively. PCR method was used for the detection of transgenic plants. First experiment revealed that the leaf explant was the best sample and MS medium containing 1 mg L-1 IBA+1 mg L-1 BAP was the best combination for in vitro regeneration of all genotypes. The results of the second experiment showed that the M4 medium (containing 50 and 75 mg L-1 Kanamycin and Hygromycin, respectively) completely inhibited the regeneration of non-transformed samples. Finally, transgenic plants were selected using PCR with specific primers for transferred genes.