نشریه علوم سبزی ها
سال دوم شماره 2 (پیاپی 4، پاییز و زمستان 1395)

In order to reduce losses and preserve the fruit quality of green bell pepper cultivar “California Wonder”, this study was designed by using a factorial experiment on the basic of a completely randomized design at Ilam University. Treatments were consisted of pre-harvest spraying of calcium chloride 0.5% (CaCl2), packaging with cellophane, pre-harvest spraying of CaCl2 0.5% with packing of cellophane (CaCl2+ cellophane) and control (without spraying and cellophane packaging). Fruits were stored at 10°C and relative humidity 90-95 percent for 20 days and characteristics were evaluated at harvest, and after 10 and 20 days storage. Results showed that increasing the storage period decreased marketability and the quality of the fruits, but all treatments preserved the quality and marketability of the fruits over the storage period. Among the treatments, weight losses and variation in total soluble solids (TSS), titratable acidity (TA), taste index (TSS/TA ratio), chlorophyll and carotenoid content were lower under calcium + cellophane treatment than what recorded for other treatments and control. Also, calcium + cellophane combination had higher marketability, texture firmness, vitamin C, total phenol and antioxidant capacity. Although, for some characteristics, the treatment’s effect was not significantly different with pre-harvest spraying of CaCl2 0.5%. Altogether, all treatments preserved the quality of fruits in post-harvest, but the combination of calcium + cellophane was better than other treatments. Therefore, using a combination of calcium + cellophane is recommended as a method for reducing losses and maintaining the quality and marketability of green bell peppers during the storing and marketing.

The number of fruits per plant is the main trait in cucumber that determines the yield potential of lines. The F1 generation was obtained from a cross between lines 118 × 119 lines. The F2 generation was achieved by inbreeding of the F1 progenies and each of the F2 plants were inbred for generation of F3 progenies. Ten plants of each F3 population were planted in separate lines in a completely randomized complete block design and on the F3 plant populations different traits were measured and recorded. After evaluation of the F3 populations, the stock-seeds of the selected lines were re-cultivated in the following year and allowed to be open pollinated. The open-pollinated off-springs of selected lines were collected in a bulk method and in the following year, re-cultivated once again to determine the genetic value of the selection. Results indicated that the bred population with an average of 39.82 fruits per plant was 37.73 percent improved in comparison to average of the F3 population (28.91 fruits per plant). Therefore, the bred population can be used as a selection sources for further breeding programs and selection of more valuable cucumber lines.

In order to evaluate genetic diversity of Iranian indigenous Fenugreek populations on the basis of morphological traits, thirteen populations were collected from different regions of Iran and the experiment was conducted based on a completely randomized design with three replications. Results revealed that all populations exhibited significant differences for majority of studied traits. Yield of landraces varied between 5.29 to 27.87gr of fresh weight. The minimum and maximum fresh weights were recorded in Marand and Marvdasht landraces, respectively. Also, landraces bloomed 46 to 79 days after sowing. Thousand kernel weight was variable from 8.60gr (Ardestani) to 29.80gr (Marvdasht). Correlation coefficients showed significant positive correlation of leaf area and fresh weight. Also, a significantly positive correlation was observed between height at harvest time with fresh weight and number of stems with number of flowers, and number of pods with number of seeds per pod. In this study, factor analysis dropped features into six main and independent groups. Factors with eigenvalues higher than one were justified 80.47 percent of total variance. Cluster analysis divided all populations into three main groups, in which, there were three, two and eight landraces, respectively. Generally, the results showed that Iranian Fenugreek landraces have a high genetic diversity in regard to the studied traits.

Drought stress is the most important factor limiting growth and production of plants. Titanium dioxide nanoparticles have different effects on morphological, physiological and biochemical properties of the plants. In this study, effects of spraying of Titanium dioxide nanoparticles (0, 50, 100 and 200 mg/l) and two levels of irrigation (normal irrigation, 5-days irrigation intervals) was evaluated through a factorial assay based on randomized block complete design with three replications. Sixty days after starting the assay, changes in chlorophyll index, leaf area, proline, protein, total carbohydrate, chlorophyll fluorescence parameters (Fo, Fv/Fm) and nutrients (potassium, manganese, Iron, and zinc) were measured. Under water deficit stress, spraying of Titanium dioxide nanoparticles, increased the amount of chlorophyll index, proline and protein content, concentrations of potassium, zinc, iron, manganese; leaf surface and reduced the amount of minimum chlorophyll fluorescence. Also, total soluble carbohydrate content increased increased in parallel with titanium dioxide nanoparticles concentration, while the treatment did not affect the amount of FV/FM.

In many sun-loving plants, shading affects their growth characteristics and yield due to the reduction of solar radiation. In order to evaluate effect of different shading levels (0, 25 and 50 percent) on growth and yield of celery (Apium graveolens L.), this experiment was carried out as randomized complete block design with four replications. Results showed that the maximum and minimum length, height and stem number of celery recorded for plants exposed to 50 percent shading and full light intensity, respectively. Leaf area and specific leaf area in plants exposed to full light decreased 330 and 42 percent, respectively in comparison to those received 50 percent shading. The Fv/Fm ratio and leaf stomatal conductance increased with decreasing light intensity. Leaf chlorophyll index, fresh and dry weight of leaf petiole and blade of plants under shade were higher than those grew under full sunlight. The maximum (718g per plant) and minimum total yield (155g per plant) obtained in shading 50 percent and full light intensity, respectively. For conclusion, celeries grown in 50 percent light intensity had better growth and yield.

Sucrose and boron as a source of carbohydrates and an effective factor in carbohydrate transport, respectively heve positive effects on seedlings’ growth. In this study, the effect of spraying sucrose and boric acid were evaluated on seedlings and fruits quality of tomato in the nursury and field, respectively. Tomato seeds (Var. SuprA) were planted in seedling tray. Seedlings were subdivided into two groups for foliar application: 1- were sprayed in the nursery, and 2- were sprayed after transplanting into the soil. Foliar application of each group was performed in three stages with concentrations of 0, 5 and 10% sucrose and 0, 0.1 and 0.2% boric acid. The results revealed that nutrition of sucrose and boric acid in nursery reduced seedlings’ height and leaf area upto 30 percent in comparison to the control, which might be desirable to tolerate the potential stress caused by transplanting process. Because of decreased shoot growth, the root to shoot ratio of seedlings increased by all treatments containing sucrose upto 35 percent compared to control. Spraying with 10 percent sucrose and 0.1 percent boric acid in nursery were significantly improved shoot dry weight to 0.04 g and carotenoid upto 0.214 mg/gFW. Also, tomato seedlings sprayed with sucrose and boric acid immediately after transplanting had positive effects on plants growth. The highest number of flowers (114.86) and the highest number of clusters with (19.7) were recorded for 0.2 percent boric acid treatment. Maximum number of fruits per plant (18.70) was recorded for spraying sucrose 5 percent plus boric acid 0.1 percent. For coclusion, increasing the carbohydrate content of transplant through sucrose foliar application is a key factor in plant establishment. It was also found that the boron element allows sucrose transfer into the plant. The simultaneous use of sucrose and boron improved sucrose absorption rates in the plants.