Effect of Exogenous Polyamines on Flower Bud Retention in Pistachio (Pistacia vera L.) Trees

Bahram Baninasab,Majid Rahemi 한국원예학회 2008 Horticulture, Environment, and Biotechnology Vol.49 No.3

Alternate bearing, the occurrence of high yield ‘ON’ year followed by low yield ‘OFF’ year, is striking in pistachio (Pistacia vera L.) trees. Flower buds of pistachio are formed a year before bloom, but abscise during the years with heavy crop (‘ON’ year). The present study was conducted to examine the effects of various concentrations of polyamines, such as putrescine, spermidine and spermine, on flower bud retention of pistachio trees cv. Ahmad Aghaei. The results showed that exogenous application of polyamines significantly increased the flower bud retention, leaf chlorophyll content, leaf and floral bud nitrogen and leaf area. Among the three polyamines tested, the highest concentration (0.1 mM) of spermine was the most effective in increasing flower bud retention. There was a positive relationship between leaf and flower bud nitrogen content and flower bud retention.

Effect of Irrigation Regimes on Water Status and Photosynthetic Parameters of Peach-Almond Hybrid (GF677) Seedlings and Cuttings

Mahdiyeh Gholami,Majid Rahemi 한국원예학회 2009 Horticulture, Environment, and Biotechnology Vol.50 No.2

Almond is one of the drought resistant species suitable for growing in the dry lands of Iran. To evaluate the response of seedlings and cuttings of peach-almond hybrid (GF677) to different irrigation regimes, an experiment was conducted under greenhouse conditions in 2007. The stratified kernels and uniform rooted cuttings were planted in 20-L pots. After determination of field capacity (FC) of pot soils, irrigation treatments were imposed by daily irrigation to FC level or irrigation to FC at intervals 2, 4, or 8 days for 96 days. Stem water potential (SWP), relative water content (RWC), stomatal conductance, transpiration rate, photosynthetic rate, sub-stomatal CO₂, and water use efficiency were determined at 32 day intervals during the experimental period. Results showed that SWP at the three measurement times was lower in seedlings under 8 day irrigation intervals (-2.14 ㎫) than in the cuttings (-1.95 ㎫). The reduction of RWC throughout the experimental period was higher for seedlings (7.1%) than cuttings (5.1%). Therefore, cuttings of GF677, through better control of stomata, decreased transpiration, increased water use efficiency and appear to be more drought-resistant than their seedling counterparts.

Morphological Evaluation of Three Native Species of Amygdalus in Iran

Babak Madani,Majid Rahemi,Bahram Baninasab,Mojtaba Mahmoodi 한국원예학회 2009 Horticulture, Environment, and Biotechnology Vol.50 No.1

Iran, with over 30 native species, is within the center origin for almonds. Shoot and root growth, and kernel characteristics were evaluated for seedlings of three endemic species, Amygdalus scoparia (syn. Prunus scoparia), A. eleagnifolia (syn. P. eleagnifolia), and A. eburnea (syn. P. eburnea). Significant differences among species were observed for most of the traits measured. Seedlings of A. scoparia were larger than A. eleagnifolia and A. eburnea, while A. eburnea had greater stem biomass, greater specific leaf weight, smaller leaf area, and lower stomatal density than the other species. A. scoparia had the most extensive root system and A. eburnea had the smallest. Shoot characteristics, such as leaf length, were often significantly correlated with root traits, though the association varied with species. Distinguishing morphological features included seedling diameter, branch angle, leaf length, root number, and total root length for A. scoparia; seedling height, root number, root diameter, leaf width, and stomatal length for A. eleagnifolia; and number of first order lateral stem, internode length, leaf area, and root length and diameter for A. eburnea. Detailed knowledge of species morphology and development patterns allows a more efficient evaluation of rootstock potential of these drought tolerant species.

Effect of Pulse Treatment with Sucrose, Exogenous Benzyl Adenine and Gibberellic Acid on Vase Life of Cut Rose ‘Red One’

Mahdiyeh Gholami,Majid Rahemi,Somayeh Rastegar 한국원예학회 2011 Horticulture, Environment, and Biotechnology Vol.52 No.5

Effects of postharvest application of two plant growth regulators viz., benzyladenine (BA) and gibberellic acid (GA_3)with sucrose in the pulse solution on the vase life of roses ‘Red One’ were investigated. Results show a maximum gain in fresh weight (18.01%) in the cut roses in the treatment with a 20 mg・L^(-1) GA_3 + 100 g・L^(-1) sucrose pulse solution. In contrast to the change in fresh weight, treatments of 10 or 20 mg・L^(-1) BA and the control recorded the maximum water uptake. A pulse solution of 10 or 20 mg・L^(-1) GA_3 + 100 g・L^(-1) sucrose or 10 mg・L^(-1) BA+ 10 mg・L^(-1) GA_3 + 100 g・L^(-1) sucrose significantly increased vase life of cut roses than the control. Treatments of 100 g・L^(-1) sucrose, control, 10 mg・L^(-1) GA, 10 or 20 mg・L^(-1) BA + 100 g・L^(-1) sucrose recorded higher petal tissue electrolyte leakage and decrease in vase life. Pulsing with a solution of sucrose at lower concentrations along with GA_3 (10 mg・L^(-1)) was promising in increasing vase life of cut roses ‘Red One’.

Nano-calcium and its potential to improve ‘Red Delicious’ apple fruit characteristics

Shiva Ranjbar,Asghar Ramezanian,Majid Rahemi 한국원예학회 2020 Horticulture, Environment, and Biotechnology Vol.61 No.1

This study evaluated the effects of preharvest nano-calcium fertilization on quantitative and qualitative characteristics of apple (Malus domestica Borkh. ‘Red Delicious’) fruit. From 70 days after full bloom to 30 days before commercial maturity, calcium chloride (0, 1.5, and 2.0%) and nano-calcium (0, 1.5, and 2.0%) solutions were sprayed on apple trees. This was performed five times during the growing season at 2-week intervals. Fruit weight, density, length (L), diameter (D), and L/D were evaluated at harvest. Additionally, several quality characteristics were measured: fruit firmness, total soluble solids (TSS), titratable acidity (TA), total phenolic content (TPC), total antioxidant activity (TAA), total anthocyanins content, starch content, fiber content, total sugars, and calcium content. The effects of nano-calcium treatment on fruit quality and quantity were more significant than that of conventional calcium chloride. The greatest improvements were obtained using 2.0% nano-calcium. TA, TPC, TAA, fiber, and starch content were significantly increased under the nano-calcium treatment. Compared to the control, TSS, total sugars, and anthocyanin content decreased under the calcium chloride and nano- calcium treatment. Our results support the use of nano-calcium as a promising fertilizer for improving the overall characteristics of apple fruit.

Improving Fruit Quality in ‘Hayward’ Kiwifruit Using Proper Leaf to Fruit Ratios and Girdling

Pedram Assar,Saeid Eshghi,Enayatollah Tafazoli,Majid Rahemi,Yazdan Gholi Khazaeipoul,Abbas Saboorrooh Monfared 한국원예학회 2009 Horticulture, Environment, and Biotechnology Vol.50 No.6

The effects of different leaf to fruit ratios, summer pruning time, and girdling on quantitative and qualitative characteristics of ‘Hayward’ kiwifruit were examined. On each vine, four uniform canes were selected and by pruning their fruiting laterals, leaf to fruit ratio was adjusted and maintained at 1:1, 2:1, 3:1, or 4:1. In control treatment, these selected canes were left intact without topping and removing any lateral growth. Half of the selected canes were girdled by removing a 5 mm strip of bark around the base of each cane, while the other half were left intact. Leaf to fruit adjustment and girdling were imposed 2 weeks after petal fall. To show how pruning time can affect fruit characteristics of the four mentioned selected canes, other canes and their laterals in each vine were pruned early (similar to selected canes) or late (in late summer) (vine general pruning methods A and B, respectively). In both methods, pruning manner was in accordance with common practice in Persian commercial orchards (heading cuts were performed after 3-4 leaves distal to the latest fruit). Finally, fruits of selected canes were harvested and analyzed. Results indicated the necessity of summer pruning performance to obtain fruits with higher quality. The importance of total leaf numbers of laterals in each cane as carbohydrate suppliers for fruits in order to support potential fruit growth was proved. Also, dependence of fruit growth in each cane on carbohydrate supply of other canes was detected. In pruned vines in method A (early summer pruned and as a result having light canopies with optimum light penetration) on girdled experimental canes, minimum leaf to fruit ratio that was required to achieve significant changes in fruit quantitative characteristics compared with control, was 1:1 for width and weight and 2:1 for length and volume. The positive effect of girdling on fruit quantitative characteristics via improving the available photosynthates supply to developing fruits was confirmed. Smaller responses of fruit growth to increasing the leaf to fruit ratios on non-girdled canes due to competition for photosynthate from other sinks, was observed. In pruned vines in method A (better canopy conditions), girdling performance combined with 3:1 and 4:1 leaf to fruit ratios resulted in higher vitamin C and total soluble solids contents, respectively. The positive effect of on time (early) summer pruning on fruit characteristics was proved.