مجله گل و گیاهان زینتی
سال ششم شماره 2 (پاییز و زمستان 1400)

Geranium has an important place in the world flower and plant industry and is one of the most popular for indoor and outdoor use. Viral diseases play an important role in reducing the quantity and quality of this ornamental plant. In this study, 72 samples suspected of viral infection with symptoms such as bright ring spots, leaf necrosis and chlorosis, spots or color breaking on the petals, as well as asymptomatic plants were collected from various greenhouses in the Mahallat and Varamin and their suburbs. Total RNA was extracted and evaluated by RT-PCR using general primers of the family Tombusviridae. In 21 samples, a DNA fragment of 500 base pair (bp) in size was amplified using Tombusviridae primers. This DNA fragment from the two isolates were sequenced and compared with the sequences available in the Genbank database. The results indicated that both isolates belonged to Pelargonium flower break virus (PFBV). The RT-PCR test was performed again using a pair of specific primers (CH1/GH2) designed to amplify a 1500 bp DNA fragment from the 3' end of the PFBV virus genome containing the coat protein gene on the same samples, that confirmed the accuracy of the results of the previous step. The amplified DNA formed on the gel of three selected isolates was extracted from the gel and subjected to sequencing. Phylogenetic analysis was performed based on the amino acid sequence of CP gene and phylogenetic tree (genealogy) was drawn using neighbor joining method. The results of phylogenetic analysis showed that the reported PFBV isolates from different countries are in two groups and three PFBV isolates of Iran were placed separately in one subgroup from the subgroups of other countries. This is the first report of PFBV in Iran.

The lack of sufficient genomic information of ornamental plants besides their polyploidy and large genome size are the main challenges ahead of their molecular breeding. Next-generation sequencing (NGS) is a viable method capable of developing a large number of DNA markers in a short course of time. Currently, single-nucleotide polymorphisms (SNPs) are recognized as one of the most studied and popular DNA markers using for various purposes in plant breeding. GBS (genotyping-by-sequencing) approach is one of the leading techniques that has emerged to evaluate the molecular characteristics of plants possessing complex or non-sequenced genomes using SNP markers. This method has so far been used for breeding and germplasm evaluation of some ornamental plant species including Rosa, Petunia, Hydrangea, and Gloxinia. Among these studies, one study is done to perform GWAS on Hydrangea macrophylla L., ten studies to investigate the genetic diversity of various ornamental species including Gloxinia, Dendrobium orchid, as well as ornamental trees Franklinia alatamaha Marshall and Cornus florida L., four studies to construct and elaborate the genetic map of plants species including Rosa and Petunia, three studies to develop molecular markers in rose, lilac and Hydrangea species and one study to investigate the genetic diversity within and between Iranian Eremurus spp. This is a potential method for examination of genetic diversity of plants, assembling high density genetic linkage maps, discovering the required molecular markers in QTL and GWAS studies, and verifying candidate genes including genes controlling the flowering process. Owing to the high efficiency and accuracy as well as the low cost per marker of this method compared to other genotyping techniques, GBS can be widely used in genetic studies, sequencing and breeding of ornamental plants.

An important characteristic of foliage plants is the production of enough lateral or basal shoots. Among the most commonly used branching-inducers are gibberellic acid (GA3) and N6-benzyladenine (BA) which are synthetic cytokinins that have been shown to increase shoot number in some plant species. The aim of this research was studying the effects of synthetic branching agents on a foliage plant. The effects of GA3 and BA on Ficus benjamina plant was evaluated under greenhouse condition. Plants were treated with foliar application of GA3 and BA at 0, 100 and 200 mg L-1. The plants that were treated with GA3 and BA at 200 mg L-1 showed the highest number of leaves and plant height. Foliar application of 200 mg L-1 GA3 + 200 mg L-1 BA increased photosynthetic pigments. The highest rate of soluble carbohydrates and reducing sugars were belonged to 200 mg L-1 GA3 and 100 mg L-1 GA3 + 200 mg L-1 BA, respectively. Results indicated that application of 200 mg l-1 of GA3 + BA significantly promoted morphological growth, chlorophyll and carotenoid content, reduced sugars and soluble carbohydrates in F. benjamina.

The Phalaenopsis orchid is the most popular genus of Orchidaceae family with high marketability due to its butterfly shape and attractive flowers. The aim of this study was to investigate the effects of cultivar, explant type, plant growth regulators and culture medium on in vitro propagation of Phalaenopsis orchid. Experiment was conducted using 4 combined treatments of benzyladenine (BA) and indolebutyric acid (IBA) (BA 2 and 4 mg L-1 with IBA 0.5 and 1 mg L-1), 2 culture media (MS and Chen), 2 types of explants (leaf and stem), and 5 commercial cultivars of Phalaenopsis orchids. The findings revealed that the studied factors had significant effects on leaf and root primordia initiation, number of protocorms, and number of leaves and roots. Among the investigated cultivars, 2 cultivars: Nottingham and Dubrovnik showed earlier leaf and root primordia initiation. Two treatments including BA+IBA (2+0.5 mg L-1 and 2+1 mg L-1), and Chen culture medium showed faster primordia initiation significantly different from the other treatments. Leaf explants produced more protocorm than stem explants. The highest number of protocorms was belonged to Nottingham cultivar, and the treatment of BA+IBA (2 to 1 mg L-1) on Chen culture medium. The number of leaves and roots of in vitro plantlets were significantly affected by various factors so that, Dubrovnik had more leaves and the Nottingham had more roots than the other cultivars. The highest number of leaves was observed in BA+IBA (2+0.5 mg L-1) treatment, while the highest number of roots was belonged to BA+IBA (2+1 mg L-1) treatment. Comparing the media, Chen medium showed more positive effects on leaf and root number than MS medium. The results of this study indicated that the success of regeneration of Phalaenopsis cultivars in vitro is influenced by the characteristics of the cultivar, medium, and plant growth regulator treatments. Nottingham cultivar and leaf explant showed better regeneration rates in vitro. Increasing the concentration of BA from 2 to 4 mg L-1, increased the time required for leaf and root primordia initiation and prolonged the in vitro cultivation period.

Floriculture is one of the most laborious agricultural activities, which according to most experts in this field, success is involved in factors such as greenhouse technology, modern technology in cultivation, marketing situation. To develop the floriculture of Iran, it is necessary to change production from the traditional methods to the new methods. The two cities of Andimeshk and Dezful are the main producers of rose cut-flowers in Khuzestan province. In this study, by field investigation and collecting data from the structure and control of environmental conditions of the greenhouse, methods of growing and maintenance of rose cut flowers, yield, conditions of growers in these two cities, present suggestions to increase yield. The data were collected from 60 commercial greenhouses producing roses in a completely randomized and referral to Agricultural Organization of Khuzestan Province. The results showed that the cooling system in 45% of Andimeshk greenhouses and 35% of Dezful greenhouses was fan and pad system. It was found that 50% and 41% of Andimeshk and Dezful greenhouses use Polar systems respectively and opening and closing the valves for temperature balance were usual. The results of irrigation system showed that the Andimeshk greenhouses used 40% gravity, 30% flooding, 20% drip and 10% hydroponics and Dezful greenhouses used 86% atmospheric stack irrigation and 14% drip irrigation. According to the obtained results, it was found that 50% of Andimeshk and Dezful greenhouses have a plastic cover with metal structures. The average annual production of cut flowers in Andimeshk and Dezful was 120,000 and 130,000, respectively. Also, the main markets for selling cut-flowers of roses were the local sales market and Tehran, and their export abroad was done through the Tehran market. The obtained results showed that 10% of the producers of Andimeshk city and 12% of the greenhouse producers of Dezful city have academic education. In conclusion, most greenhouse management operations are performed traditionally and the use of new methods; especially in cooling, irrigation and feeding systems to increase the yield and quality of flowers is essential. It is also suggested that introductory courses in the field of greenhouse management and breeding and maintenance be seriously considered.

Lisianthus is in the top ten flowers in the world and in 2017, it was the fifth largest exporter and seller of ornamental plants in the world. Resistance to fungal diseases, especially Fusarium, is one of the most important breeding objectives for lisianthus. Little work has been done on the modification of resistance to fungal diseases in this ornamental plants. Therefore, gene transfer of chimeric chitinase to lisianthus will be an important contribution to achieve this important goal. The transfer and expression of chitinase gene in plants show a high level of resistance to fungal infections and a delay in the onset of symptoms when exposed to fungal pathogens. The researchers showed that the activity of chimeric chitinase in destroying fungal walls is significantly different from that of Chit42 chitinase. The aim of this study was to achieve resistance to Fusarium solani in lisianthus by transfer of chimeric chitinase gene using Agrobacterium tumefactions. In this study, the effect of different culture media, MS, ½MS and LB, two pH values of 5.2 and 5.8 and 30 and 15 mg L-1 sucrose and 30 mg L-1 maltose in the inoculation medium were investigated. The results showed that the B treatment with MS inoculation medium containing 30 g L-1 maltose with a pH of 5.2 gave the best response in gene transfer to lisianthus and the presence of a more stringent selection medium containing 100 mg L-1 of kanamycin was superior to the other treatments with an average regeneration of 11.13 plantlets per leaflet. The results of this study show that MS medium is more efficient than LB medium for gene transfer to lisianthus. Lowering the pH and changing the carbohydrate source from sucrose to maltose in the inoculum medium increased the transformation efficiency. In this study, 471 plantlets were generated from 45 leaf explants during gene transfer of chimeric chitinase to lisianthus in a more stringent selection medium and out of 21 randomly selected plantlets and lines, 10 lines were selected by PCR and 8 lines responded positively to bioassay test. This is the first report of chimeric chitinase gene transfer in lisianthus.