International Journal of Horticultural Science and Technology
Volume:4 Issue: 1, Winter - Spring 2017

FAO promotes Sustainable Production Intensification (SPI), which consists of a technology menu for optimizing crop production per unit area, taking into consideration the range of sustainability aspects including potential and/or real social, political, economic and environmental impacts. The author suggests that Genetically Modified Organism (GMO) cropping is not only well aligned to SPI but also that this technology is a way to maximize the SPI principles. GMO crops cover about 13 percent of the world’s cropped land. More than three quarters of this area is within the three countries that also lead the production and export of the major food and feed commodities: USA, Brazil and Argentina. The remaining area is spread across about 29 countries, mostly developing countries and a few industrialised countries. Four crops account for the majority of land under GMO crops: corn, soybean, cotton, and canola. About 90 percent of the soybean and 80 percent of the corn that is traded in the world market is genetically engineered. Consequently a very large part of the world population likely eats every day food that either contains GMOs or GMO derivatives or animal products derived from GMO fed animals. It has been the fastest adopted agricultural technology, rising to its current level over only twenty years. Further increases in production will mainly occur in developing and low-income countries. In the EU, a large majority of the member states have chosen to rule against GMO cultivation. It is essentially a ‘marketing’ strategy. Nevertheless, GMOs land on European tables daily in one way or another. The developing world and its low income countries are gradually improving their policy, institutional and administrative environments towards the adoption of modern biotech rules. The technology is simple, has been thoroughly tested and through extensive scientific research and testing has been shown to be as safe as crops bred and developed by other techniques. The advantages in terms of higher crop productivity and lower production costs are substantial and widely proven. GMOs are also substantially eco-friendly but more research and development is required to improve herbicide management. Only a small fraction of the GM achievements, and opportunities, are being widely exploited. Other tested discoveries, which offer valuable strategies to address the challenges of climate change, productivity concerns and human health plagues/malnutrition that are widespread in low income countries, are yet to be adopted on a meaningful scale. There is no credible evidence that GMOs constitute a threat to human health. International rules and regulatory frameworks exist and are acknowledged. Cultural, which at times appear to be ideological, barriers more often of the developed world, are hindering rational technological advancement and food security and adequacy. In order to feed the growing world population, heading towards 9 billion or more by 2050, there is the need to increase food production by 60-70 percent, and to double it in the developing world where the highest demographic growth will occur. A safe and sustainable technology exists that can contribute substantially towards this target and humanitarian responsibility.

Different dates for apples fruit harvest (Malus domestica Borkh. Cv. Fuji) were studied to determine physiochemical changes during the storage. Fuji apples were harvested from 9 September till 23 October, at five different times and stored at 0±0.5 °C and 95% relative humidity for 120 days. To determine the best harvest date for maximum quality and storability, physical and chemical parameters were measured at each harvesting time and after 40-day periods until the end of 120 days of storage. Results showed that, the fruit quality parameters at harvest and after storage, depends on the degree of the ripeness at which the apples were harvested. Fruits from the first harvest, were firmest before and after storage and had the lowest phenolic compounds at the end of storage. First, second and third harvest date samples, had a decrease in phenolic content and total antioxidants activity during storage, but the fourth and fifth harvested fruits were opposite. Total soluble solids and Titrable acidity were affected by the harvest date and duration of storage. First and second harvest date samples showed an increase in total soluble solids during 120 days of storage but it was opposite in third, fourth and fifth harvested samples. The fifth harvest date samples characterized with oblate fruit shape and high weight loss during storage.

Adaptation and defense responses are the consequences of exposure to drought stress in plants. Salicylic acid (SA) as a natural signaling molecule poses a significant impacts on various aspects of plant growth and development. This study investigates the effects of SA on carotenoids content, lipid peroxidation rate and antioxidant enzymes activities. A pot experiment was conducted using a factorial pattern based on a randomized complete block design with three replications under greenhouse conditions. The variables in the experiment included grapevine cultivars (‘Rasheh’ and ‘Bidane Sefid’), irrigation periods (5, 10 and 15 day intervals) and SA concentrations (0, 1 and 2 mM). Results showed that with increasing the drought stress levels, increase in carotenoids, malondialdehyde (MDA) contents, catalase (CAT), ascorbate peroxidase (APX) and guaiacol peroxidase (GPX) enzymes activities were detected. Carotenoids content, catalase (CAT) and ascorbate peroxidase (APX) and guaiacol peroxidase (GPX) enzymes activities were higher in the Rasheh cultivar compared with the ‘Bidane Sefid’ cultivar. Carotenoids content, CAT, APX and GPX enzymes activities increased by application of salicylic acid. . According to the obtained results, the Rasha cultivar showed a greater tolerance to water stress in comparison with Bidane Sefid cultivar, suggesting that SA is capable of inducing drought stress tolerance in plants.

Plant propagation originated from the mature tissues is the most desirable method in producing clonal plants, however microbial contamination usually is the main concern during regeneration processes. Moreover, commercial production of plants using clonal propagation is considered as high throughput method due to the removal of seasonal barriers, lower cost of production with higher yield when compared to the conventional propagation methods. In this research the regulatory roles of 2-iso-pentenyl adenine (2iP) and Zeatin (Z) along with two temperature regimes, 22 and 28 °C, on mature explants of Picea abies (L.) H. Karst was evaluated for adventitious shoot regeneration. Norway spruce micro-cuttings considerably benefited from Ridomil and Benomyl treatments for fungal decontamination in explants taken in spring or fall. The highest percentage of regenerated explants (68.75%) as well as the highest numbers of adventitious shoots per explant were obtained in MS media supplemented with 4 µM Z. Furthermore, the highest length of proliferated shoot (1.17 cm) was achieved at 3.2 µM 2iP treatment. However, there were no significant differences in the length of adventitious shoots using different concentrations of 2iP. Incubating explants at 28˚C resulted in null or deformed regeneration in Norway spruce.

Storage of Lime (Citrus aurantifolia L.) fruits, originally a tropical fruits, in low temperature confronts with several difficulties due to the risk of chilling injury (CI). To develop an effective method aiming to reduce CI, the effects of treatments containing 0, 0.5 and 1 Mg/lit brassinosteroids (BRs) and hot water (HW) including 20°C as control, 45 and 55°C for 30 minute on CI was studied. Moreover lipid peroxidaion, hydrogen peroxide, catalase (CAT) and peroxidase (POD) activities were investigated in lime fruits stored at 1°C for 21 days. The CI, lipid peroxidaion, hydrogen peroxide were significantly reduced by BRs treatment particularly at 1Mg/lit and 45°CHW treatment. Furthermore fruits treated with 1Mg/lit BRs and 45 °C HW treatment exhibited significantly higher CAT and POD activities in comparison with the control fruits. These results suggest that BRs and HW treatment protect lime fruits from CI by enhancing antioxidant enzymes such as POD and CAT activities, and reduce lipid peroxidaion, hydrogen peroxide contents, and maintaining membrane integrity.

To study effects of salicylic acid (SA) treatments (0, 0.5, 1 and 2 mM) in two forms of seed priming (for 24 h) and spraying on seedling at 4-6 leaf stage an experiment was conducted on periwinkle (Catharanthus roseus Don.) with and without exposure to a mild cold stress of 8 °C (for 32 h). Seeds were sown in trays containing peat-based substrate (with 20% sandy loam field soil). Transplants of both groups were treated with mild cold. Seedlings were grown in greenhouse with an average day/night temperature of 25/20± 2°C until their blooming. Seed emergence rate and percentage, activities of catalase (CAT), guaiacol peroxidase (GPX), polyphenol oxidase (PPO), CAT gene expression, height and number of nodes per plant, and days to flowering were evaluated. Results showed that mild cold stress together with salicylic acid at 0.5 mM (as either seed priming or spray on seedling) was the best treatment to accelerate the flowering, and improve growth parameters and antioxidant enzymatic activities. Thus, mild cold stress enhanced the positive effects of SA treatments on cold acclimation of periwinkle (particularly when associated with spraying, which is a simple administration method). Accordingly, it might be recommended for its seedling production and cultivation in temperate climates to prevent late spring frost damages.

Micro-propagation of olive provides the possibility of producing clones of native plants with appropriate attributes and mass reproduction in short period of time, compared to conventional methods. Apical dominance in olive explants limits the growth of lateral branches in vitro. The effect of Woody Plant Medium (WPM), Olive Medium (OM) and Murashig and Skoog (MS) with carbohydrate source (mannitol and sucrose), was investigated for in vitro shoot proliferation of olive. Different concentrations of sodium dikegulac (0.0, 2.5, 5.0, 7.5 and 10 mg L-1) along with 3 mg L-1 zeatin and 0.5 mg L-1 BAP and two light qualities (red and white) were used to overcome apical dominance. Effects of different IBA concentrations on the in vitro root induction were also investigated. More than 74% of explants rooted when IBA was used at 2 mg L-1. OM was the most effective medium, resulting in better and morphologically superior microshoots. Mannitol showed a positive effect on shoot proliferation. Using sodium dikegulac at 5 mg L-1 under white light significantly stimulated axillary bud growth. In the corresponding concentrations of sodium dikegulac, red light had a significant effect on longitudinal growth compared to the white light.

Disturbance in water relations is the major causes of vase life reduction and senescence in cut flowers This problem is mainly due to microorganism proliferation in the vase solution which leads to vascular occlusion and reduction in solution uptake by cut flowers. Therefore a comprehensive study was conducted to evaluate the biocidal effect of nano silver particles (NSP) and compare it with some previously applied biocides. Roses (cv. Cherry Brandy) were treated in a completely randomized design with: colloid of NSP, citric acid, aluminum sulfate, hydroxyquinoline citrate (HQC), calcium hypochlorite, sodium hypochlorite (NaOCl), tap water, or sterilized distilled water as vase water or solution. Longest vase life was observed in flowers treated with nano silver particles, aluminum sulphate and citric acid, respectively. Nano silver particles, HQC and calcium hypochlorite were the most effective treatments in controlling microbial population followed by aluminum sulfate as the second effective treatment. Nano silver particles, HQC and calcium hypochlorite completely inhibited the microbial growth during the first six days of experiment. Moreover, aluminum sulfate retarded microbial growth, proliferation and growth rate more efficiently than others. Each treatment allowed proliferation of a specific microbe. In general, two yeasts, six fungi, and 26 bacterial colonies were isolated from different vase solutions. Among the isolated fungi, one isolate was Trichoderma harzianum and the five other were different strains of Fusarium solani. Identified bacterial isolates were Bacillus sp., Coccus spp., Streptomyces sp., Pectobacterium sp., Burkholderia sp., and Pseudomonas sp. Bacillus was the most wide spread microorganism in most treatments. Identified Bacillus sp. isolates were B. polymexa, B. subtilis, B. megaterium and B. circulans. Since nano silver significantly improved vase life and effectively controlled microbial proliferation in vase solution, our results suggest that nano silver application could be considered as a biocidal preservative solution for rose cut flowers.

Landscape groundcover plants are a diverse group of trailing or spreading species that naturally form continuous soil coverage. Ground cover plants that were used in this study consisted of vegetative propagules of: Vinca minor L. ٬Variegatum’, Vinca minor L. ٬Green’, Oxalis brasiliensis G. Lodd, Trifolium repens L. , Phyla nodiflora L. and Frankenia thymifolia Desf. The aim of this study was to compare some physiological and biochemical responses of each species used under seasonal changes in Shiraz climatic conditions. Several factors including chlorophyll and relative water content (RWC), electrolyte leakage (EL), proline content, soluble sugars and starch levels and antioxidant enzyme activities of these ground covers were investigated. Results showed that chlorophyll and RWC content were decreased in all ground cover plants during summer time. Furthermore, considerable seasonal variations in antioxidant enzyme activities were detected in all of the studied plants. The highest activity of CAT was obtained in summer, while SOD, POD and APX had their highest activities in autumn and winter seasons. Proline concentration in F. thymifolia was higher than the other species, especially in mid-winter. According to the results of this research, it appears that plants show different mechanisms against natural adverse environmental conditions. It can be concluded that F. thymifolia and P. nodiflora are well-matched with warm season and T. repens and V. minor are well-matched with cool season environmental conditions. Therefore, these plants can be recommended for cultivation in Shiraz green space and the same conditions elsewhere.

Cucumis melo L. is one of the most economically important horticultural crops worldwide. However, low plant regeneration frequency of this plant during genetic transformation is the major hurdle for applying biotechnological approaches. Hence, this study aimed to evaluate the effect of 6-benzyladenine (BA), cefotaxime (CTX), kanamycin (KAN), and indole-3-acetic acid (IAA) on the regeneration of cotyledonary petioles generated from 6-day-old in vitro grown seedlings. Results showed that application of 1.5 mgl-1 BA plus 250 mgl-1 CTX and 1 mgl-1 BA with 1000 mgl-1 CTX formed the most efficient media for plant regeneration. The highest callus production was recorded on medium containing 1 mgl-1 BA with 250 mgl-1 CTX and 1.5 mgl-1 BA with 750 mgl-1 CTX. Medium containing 500 mgl-1 CTX plus 0.1 mgl-1 IAA efficiently induced both root \ and leaf formation. All regenerated plants were died by adding 100 mgl-1 kanamycin therefore this level considered as threshold level for kanamycin application.. Overall, the results indicated that presence of BA plays an essential role for melon regeneration and cefotaxime can be considered as an auxiliary agent.

Digital image processing is an emerging tool to predict fruit quality; therefore present study was carried out to develop an image processing technique for investigating the storage life of cantaloupe. Potassium permanganate (KMnO4) impregnated materials were used to prolong the postharvest life of cantaloupe fruit and the effects of these treatments were evaluated by 3 image textural features parameters and flesh firmness. The treatments were divided into seven groups containing untreated, conventional paper impregnated with 7% KMnO4, nanozeolite impregnated with 7% KMnO4 and nanosponge impregnated with 0, 4, 7 and 10% KMnO4 respectively in packages. Findings of the investigations showed that the nanosponges impregnated by 7 or 10% KMnO4 could preserve the quality of cantaloupe over time by maintaining its color and flesh firmness which could be a result of ethylene absorption. Nanozeolite covered with 7% KMnO4 was also a good compound to preserve the fruit firmness. Image processing features including Entropy was increased and Homogeneity was decreased during cold storage whereas, fruits that are treated with nanosponge impregnated with 10% KMnO4 showed less Entropy and more Homogeneity than other treatments. Moreover, all KMnO4 treated fruits had better values of flesh firmness and image textural parameters than control. A significant correlation was observed between flesh firmness and image parameters. In total, nano-materials showed acceptable performance in extending the postharvest life of cantaloupes based on the fruit firmness and our findings illustrated that the image processing technique can be used to assess the quality of cantaloupe fruits during storage.

Increasing quality and vase life of cut flowers play vital role in flower production industry. . Lisianthus (Eustoma grandiflora cv. Echo) has short vase life and it has been revealed that ethylene directly affect the initiation and process of senescence of petals. In this study, the effects of Silver and silicon nanoparticles with four concentrations of 0, 10, 20 and 40 mg L-1 with 4% sucrose as a support solution were evaluated on post-harvest life of ‘Cinderella Lime’ Lisianthus. The morphological and physiological parameters such as microbial population, flower vase life, relative fresh weight, solution uptake, total chlorophyll, ethylene and total dissolved solids were measured. Results revealed that all treatments extended the flower vase life when compared to control. The most effective treatment was the Highest concentration of nanoparticles (40 mg L-1). The average vase life of flowers was about 5 days in control (without any nano particle treatments) however; it reached to 17 days in flowers treated by 40 mg L-1 of both nanoparticles. Relative fresh weight, solution uptake, total chlorophyll, and total dissolved solids were also increased in the treated flowers, especially at higher concentrations. Microbial proliferations were not observed by application of both nanoparticles (Silver or Silicon) at 40 mg L-1 therefore this concentration was considered as the most effective level for both nanoparticles. Nano silver were more effective than silicon for reducing ethylene content. Overall the results suggest that silicon nanoparticle (40 mg L-1) is applicable as antimicrobial compound in combination with silver nanoparticles (40 mg L-1) as ethylene signaling inhibitor to increase the vase life of Lisianthus flowers commercially.