Journal of Horticulture and Postharvest Research
Volume:1 Issue: 2, Sep 2018

Tunisian garlic is widely threatened by the attack of several viruses genus. For this purpose, a reliable protocol was established for rapid in vitro propagation of local garlic (Allium sativum L.) cultivars for large-scale production of virus-free plants and high quality bulblets.

Well disinfected shoot-tips of 1 mm were used as explants and cultivated on MS basal solid media enriched with various growth regulators: 6-Benzylaminopurine, α-Naphthaleneacetic acid, Kinetin, Indole-3-butyric acid and 2-isopentenyladenine for assessment of shoot formation, shoot proliferation and bulb formation.

Among the different phytohormone concentrations and combinations, MS basal medium without any growth regulators (M0) was found optimal for shoot-tip initiation (96% explants development) and plantlets elongation (56.26 mm). For shoot proliferation, the M1 culture medium containing 1 mg L-1 BAP and 0.25 mg L-1 NAA was the best, giving a multiplication rate of 1.7 plantlets/explant. Shoots on M0 culture medium formed bulblets earlier. Multiple bulblets per explants were obtained on medium M22 containing 2 mg L-1 Kin and 0.1 mg L-1 NAA. Separated bulblets were transferred individually on bulbification media. Non-dividable bulblet was developed in various sizes.

Bulblet acclimatization step needs to be well studied for high quality cloves production.

This efficient optimized in vitro protocol will be successfully applied for large multiplication of virus-free garlic cultivars.

The study of effects of 1-Methylcyclopropene (1-MCP) on ripening of bananas is still an important issue for commercial application of 1-MCP on bananas. Mature green bananas were treated with ethylene only (100 µL L-1 for two consecutive days) and ethylene the same treatment followed by 1-MCP (300 nL L-1) for 24 h to evaluate the ethylene and 1-MCP effects on ethylene biosynthesis enzyme activities. Ethylene production of whole banana fruit, ACC synthase (ACS) and ACC oxidase (ACO) activities in the pulp and peel of samples were measured. The result showed that ethylene production rate by the control fruit was significantly greater than the ethylene production rate by the 1-MCP-treated fruit at days 4, 8 and 10. However, changes in ethylene production were similar in both control and 1-MCP-treated bananas. The banana peel and pulp show different patterns of ethylene production during ripening. At the onset of ripening pulp tissues showed higher levels of ACS, and lower levels of ACO activity than peel. Assays of ACO and ACS activities in ethylene-treated fruit showed that the peel had higher levels of ACO activity than the pulp. The ACO and ethylene production were inhibited by 1-MCP treatment whereas ACS increased following 1-MCP application.  Evaluation of ACS and ACO activities during different seasons.  Pulp and the peel of bananas respond differently to ethylene and 1-MCP treatment with a greater impact on peel than the pulp. The findings of this study allow 1-MCP to be used in a more commercially reliable manner.

Due to pharmaceutical value of Stevia plant (Stevia rebudiana Bertoni.), this study was done to introduce a new protocol for rapid mass propagation of itthrough tissue culture. In MS medium shoot proliferation of stevia by six concentrations of BA (0, 0.1, 0.2, 0.3, 0.4, 0.5 mg·l-1) and root induction by four concentrations of IBA (0, 0.025, 0.05, 0.1 mg·l-1) was investigated.Rooting of cuttings was done both in vitro and ex vivo conditions. According to the results, the most number of stems obtained in MS medium containing 0.3 mg l-1 BA. The highest length of stems obtained in MS medium without BA and the most number of leaves observed in MS medium supplemented with 0.4 mg·l-1 BA. In in vitro situation, the most number and length of roots obtained in MS medium without IBA. The most number of rooted cuttings was obtained in IBA solution after 72 hours and about 70% of rooted cuttings were healthy.  It had no limitation to report. In conclusion, it seems that the potential of producing root and shoots in stevia plant is extremely high, so its proliferation is possible using low concentrations of plant growth regulators in in vitro culture.

Vegetables are important sources of carbohydrates, proteins, vitamins and minerals. Bell peppers, the fruit of Capsicum annuum L. is one of the most important commercial crops in the world. This study was conducted to determine the effects of nitrogen (N) doses on growth and yield of sweet pepper under field conditions. Treatments consisted of 0, 50, 100 and 150 kg N ha−1. Plant height, Leaf chlorophyll index, flower number, yield, fruit seed number, 1000 seed weight and vitamin C were assessed at immature and mature. Nitrogen rate increasing affected significantly plant vegetative growth (plant height, lateral stem number, and leaf chlorophyll). The highest length and number of lateral stem and leaf number were obtained in plants treated with100 kg N ha-1.The results indicated that reproductive factors (weight and volume of fruit, plant yield, and 1000 seed weight) were influenced by nitrogen fertilizer. It was observed that fertilization with 150 kg N ha-1 resulted to the highest fruit weight and fruit yield. Although there were no significant differences in vitamin C content among treated plants with different nitrogen levels at a mature stage, it was shown significant differences between treated plants and control. If we could use several sources of nitrogen fertilizer such as ammonium nitrate and ammonium sulphate, then it was compared themو it seemed that we got better results about sweet pepper. Results showed that nitrogen fertilization has a strong impact on the vegetative, flowering and reproductive growth of pepper plants.

This study was conducted to evaluate the influences of variety and flowering time on physio-morphological and chemical characters of Dragon fruit. Two varieties (BAU Dragon fruit 1 and BAU Dragon fruit 2) and four flowering times (May, June, July, and August) were selected for this investigation. The experiment was laid out in a randomized complete block design with five replications. Significant variations were observed between two varieties of Dragon fruit. It was found that BAU Dragon fruit 2 exhibited better performances on studied parameters as compared to BAU Dragon fruit 1. It was observed that at 38 days after fruit setting (DAFS), BAU Dragon fruit 2 produced highest fruit length (10.01cm), fresh weight (307.94 g/fruit), dry weight (24.85 g/fruit), pulp weight (168.98 g/fruit), peel weight (91.32 g/fruit) and total soluble solids (TSS) (25.16% Brix) as compared to another variety. The combine effects of variety and flowering time showed that August flowering of BAU Dragon fruit 2 produced maximum fruit length (10.74 cm) and peel weight (115.65 g/fruit) while May flowering of BAU Dragon fruit 2 produced maximum fresh weight (456.50 g/fruit), pulp weight (302.12 g/fruit), moisture content (94.63%) and TSS (27.17 %Brix) as compared to other flowering time. In terms of time required to fruit maturity, August flowering BAU dragon fruit 2 matured earlier (30.6 days) than June flowering (35.04 days).  Evaluation of more varieties of dragon fruit was a research limitation. These findings reveal that flowering time irrespective of variety has direct effects on fruit growth and development of Dragon fruit.

The aim of this study was to investigate the effect of fertilizer type and irrigation scheduling on biomass partitioning in saffron. The experimental factors were saffron fertilization (no-fertilizer, cow manure and NPK chemical fertilizer) and irrigation regimes (FI=7200 and DI=3600 m3 ha-1) which were tested during 2015-16 growing season, using a factorial layout. The weights of roots and leaves had an increasing trend up to 72 and 114 days after first autumnal irrigation (DAFAI), respectively, and then were decreased. Corm production started from 51 DAFAI and its maximum was obtained at DI and chemical or organic fertilizer application. In all combined treatments corm production (maximum rate between 114 and 157 DAFAI) was prior to corm filling (started from 135 DAFAI) and both mentioned indices were higher in DI. The weight of replacement corms per clone in plants that were treated by cow manure and received 7200 m3 ha-1 water, was higher (~10%) than all other treatments. Corm growth rate increased from 50 DAFAI and the maximum value (0.32 and 0.34 g day-1 plant-1 in 56 and 78 DAFAI, respectively) obtained at combined treatment of FI × cow manure. Access to similar scientific references on the topic of research was a limitation. This study was the first research which specifically deals with the allocation of photo-assimilates in saffron and based on its findings, application of 3600 m3 ha-1 water plus cow manure is an appropriate strategy in saffron cultivation during first growing season.

The aim of this study was to investigate the effects of ambient temperature storage condition (27-29°C) and domestic cooking on contents of carotenoids, chlorophylls, vitamins and minerals in the leaves of Gnetum africanum.  Carotenoids were separated and analyzed by HPLC. Total-carotene content, vitamins and minerals were assessed spectrophotometrically. Main Results indicated that G. africanumwas rich in lutein (528.87 µg g-1 (dry weight basis) and total β-carotene (248.10 µg g-1). There was no statistical increase in total β-carotene content due to cooking, but there was a decrease due to storage. Total β-carotene isomerized more during thermal processing than in storage. Cooking decreased (p>0.05) the contents of chlorophylls, water soluble vitamins and minerals. Cooking and storage of G. africanum resulted in significant losses in ascorbic acid, riboflavin and niacin. Cooking also reduced the potassium, calcium, magnesium and zinc. Iron contents of cooked and stored samples were higher than that of the raw sample. We had to travel over 600 km to use facilities for carotenoid analysis.  The concentrations of lutein, β-carotene and certain micronutrients in G. africanumare much higher than typical contents in conventional edible leafy vegetables. The results of this study therefore provide evidence that G. africanum leaf could be an important contributor for improving the nutritional status of rural and urban people.