Pomology
Mansour Jalali; Noorolah Moallemi; E. Khaleghi; Shoreh Zivdar; Mostafa Rahmati-Joneidabad
Abstract
IntroductionThe date palm tree tolerate high temperatures, drought and salinity more than other fruit crop, that is why date palm tree is named the tree of life in the desert. Date palm (Phoenix dactiylifera) is one of the fruit tree crops that is cultivated in arid region of Middle East and North Africa ...
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IntroductionThe date palm tree tolerate high temperatures, drought and salinity more than other fruit crop, that is why date palm tree is named the tree of life in the desert. Date palm (Phoenix dactiylifera) is one of the fruit tree crops that is cultivated in arid region of Middle East and North Africa having a significant role on the economy of many countries in these regions. Fruit thinning is one of the major operation for improving the quality of dates as also for other fruit trees. Quality of dates is improved by increasing fruit weight and size and regulating date palm production by reducing the magnitude of year to year production affecting the date palm. Date palm orchard operations include all operations that are repeated annually to produce date fruit. Alternate bearing is common phenomenon in date palms. The thinning is one of the main methods that often helps to solve this problem. The main purpose of thinning is to create a suitable balance and often to increase the leaf to cluster ratio. It is creating a balance between vegetative growth and flowering and reducing the possibility of aging in the Alternate bearing. Fruit thinning is one of the necessary operations that affects the growth, quality, fruit yield and regulation of the Alternate bearing of the tree. The thinning process is performed manually, mechanically and chemically. Therefore, choosing a thinning method that saves time and money is necessary for date palms, especially in critical situations. The purpose of this experiment was conducted to investigate the effect of manual and chemical thinning on qualitative characteristics in different stages of date fruit development of the Khadrawi cultivarMaterials and MethodsAn experiment was carried out as factorial experiment based on randomized complete block design with 3 replications at Shahid Chamran University of Ahvaz in 2022 and 2023. The Experimental factors included: hand thinning (No hand thinning, removal of 33%, removal of 25% of the total number of strands) and chemical thinning (zero, 50 and 100 mg per liter of naphthalene acetic acid). Chemical and strand thinning were done in the Hubabok stage (about 4 weeks after pollination) and the Kimri stage (12 to 13 weeks after pollination), respectively. In two consecutive years, the fruits were transferred to the plant physiology laboratory of the Department of Horticultural Sciences, Faculty of Agriculture, Shahid Chamran University of Ahvaz. The qualitative traits such as total soluble solids (%), pH, total acidity (%), taste index, antioxidant activity (%), total phenol (mg/gr FW), total soluble tannin (mg/gr FW), ascorbic acid (mg/gr FW), poly-galacturonase enzymes (U/gr FW), methyl pectin esterase (U/gr FW), cellulase (U/gr FW) and invertase (U/gr FW) and the percentage of reducing (%), non-reducing (%) and total sugars (%) were measured. Results and DiscussionThe results of this experiment showed that in the Tamar Stage, the interaction of hand and chemical thinning improved the qualitative characteristics of the fruit and on the characteristics of soluble total tannin, polygalactronase activity, pectin-methylesterase and reducing and total sugars, and the effect of hand thinning on total and percentage phenol and Non-reducing sugar and chemical thinning had a significant effect on ascorbic acid and cellulase enzyme. The results showed that there was upward trend in amount of total soluble solids, pH, total acidity, taste index, poly-galactronase, pectin-methyl-esterase, cellulase and invertase enzymes and the reducing and total sugars from the Kimri to Tamar stage. Also, there was downward trend in amount of total phenol, total soluble tannin content, ascorbic acid, and non-reducing sugar percentage from the Kimri stage to the Tamar.ConclusionsThe Khadrawi date variety has short strands, which results in a significant density of fruits on the strands of a cluster, which leads to large changes between fruits in most of the biochemical properties and has a negative effect on marketability. Fruit thinning is one of the most important agronomic works in the groves, which improves the quality characteristics of the fruit. In general, the although, hand thinning is more expensive, time-consuming and relatively more difficult than chemical thinning, but our finding showed that the quality of date fruit of Khazrawi cultivar improved by removing 25% of the total number of strands and chemical thinning with 100 mg/liter naphthalene acetic acid and these treatments is recommended for palm growers.
Mehdi Mohebodini; Zahra Azimzadeh; Esmaeil Chamani; Malihe Erfani
Abstract
Introduction: Lily (L. ledebourii) is the rarestspeciesof thegenusLilium, and grows in Caucasus region. Iranis one of the important distribution areas of this endangered species. It is important as an ornamental plant due to its large and attractive white flowers that are equal to those of commercial ...
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Introduction: Lily (L. ledebourii) is the rarestspeciesof thegenusLilium, and grows in Caucasus region. Iranis one of the important distribution areas of this endangered species. It is important as an ornamental plant due to its large and attractive white flowers that are equal to those of commercial lilies in terms of beauty.The two main constraints on growing this plant are a low multiplication rate and the high cost of bulb production. Five to ten flowers commonly appear on each plant, even specimens with up to 15 flowers have been observed. Plant tissue culture techniques are widely used in plant propagation and using these methods can effectively provide micro-propagation of this plant in large scale. High percentage ofregeneration is necessary for plant protection, using in the breeding programs and gene transfer to this plant. Therefore, the effect of plant growth regulators and abiotic stress (ultrasound) werestudied on the bulblet production and root induction of Lilium ledebourii.
Materials and Methods: The experiment was factorial based on completely randomized design with four replicattions and was carried out in tissue culture lab of University of MohagheghArdabili in 2015. For this purpose, segmentsof scale explant was treated with ultrasound and cultured on MS medium supplemented with different concentrations of NAA and BA alone and/or in combination with each other. In this experiment, different concentrations of NAA (0, 0.01, 0.1 and 1 mgl-1) and BA (0, 0.01, 0.1 and 1 mgl-1) and different Ultrasound exposure duration (0, 5, 10, 20 and 30 second) were studied. In order to remove possible contamination from the media, all media were autoclaved for 20 minutes at 121 °C. At the end of the experiment, the number of bulblet, root length, fresh weight of bulblet were recorded. The cultures were kept at 25±2°C under illumination with daylight fluorescent lamps (30 mol m-2s-1) at 16 h photoperiod. Data was subjected for analysis of variance and compare means using SPSS 16.
Results and Discussion: The results showed that ultrasound had negative effect onroot length, so that the highest root length was observed in explants without ultrasound treatment. Result also indicated that ultrasound had positive effect on bulblet production and root induction. A different effect of growth regulators was observed in similar media on the bulblet formation percentage. The 0.1 NAA concentration had a higher efficiency while increasing NAA insignificantly decreased bulblet induction. The highest total weight and number of bulblets obtained by 0.1 mgl-1 NAA. Concentrations of NAA increased rooting percentage. Different concentrations of NAA had also significant effects on some traits. So that, the highest weight of bulblets obtained by 0.01 and 0.1 mgl-1 BA and the highest number of roots obtained in control. Bulblet maximum mean weightwas in30 seconds ofultrasoundtreatment, which hada significantdifference with the control treatment (without ultrasoundtreatment). In the other hand, ultrasound increased the number and weight of bulblets.Mechanical stress and microstreaming by acoustic cavitation might be considered as the most possible cause of the various physiological effects of ultrasound on cells. The enhancement of V-ATPase transport and ATP hydrolysis activities seem to be an ultrasound-induced metabolic response of cells. High-intensity ultrasound is well known to be destructive to biological materials, disrupting the cell membranes and deactivating biological molecules such as enzymes and DNA. Low-intensity ultrasound, on the other hand, has shown a range of sub lethal biological effects that are of potential significance in biotechnology. There are several processes that take place in the presence of cells or enzymes activated by ultrasonic waves. High-energy ultrasonic waves break the cells and denature the enzymes. Low-energy ultrasound can modify cellular metabolisms or facilitate the uptake of nutrient, and make them easily through the cellular walls and membranes. In the case of enzymes, the increase in the mass transfer rate of the reagents to the active site seems to be a most important factor.
Conclusions: The results showedthatthebulblet production at first stages and a little root formation in tissue culture is useful for fast bulblet inductionandthenrooting. Finally, it seems that ultrasound in combination with plant growth regulators have the potential to produce the highest average number of bulblets in the scale explant.
