مجله گل و گیاهان زینتی
سال چهارم شماره 1 (بهار و تابستان 1398)

One of the social and citizen demands that is increasing in developing countries, is the expansion and rehabilitation of urban green spaces. Population growth and lack of sustainable water resources is one of the important challenges facing the arid regions. Change in style and paradigm of landscape design in arid areas with regard to the priority of reducing water consumption, can lead to social discontent caused by xeriscaping and creation of low input green spaces. Rising visual demand in society towards green spaces in recent decades as a result of improper selection of landscape design patterns, especially in dry areas, is the main reason for a possible conflict between aesthetic preferences and sustainable green space in these regions. In xeriscaping, integration of effective factors in aesthetic perception with relevant variables in planting design less has been under consideration. Effective factors in aesthetic perception are nine visual concepts include coherence, disturbance, stewardship, imageability, visual scale, naturalness, historicity and ephemera. Seven fundamental principles of xeriscaping are plan and design for water conservation, improve the soil, limit turf area or select alternatives, irrigate efficiently, select appropriate plants and hydrozone plants, mulch to reduce evaporation, maintaining a xeriscape. Despite researches showing that xeriscaping could usually reduce landscape water consumption by one-third however, many people were initially reluctant to substitute it for conventional landscaping. A common perception was that xeriscape were drab and barren and featured nothing more than rocks and some succulent and thorny plants. In this paper, on one hand the aesthetic preferences of landscape and green space and also options of design in arid regions of Iran have been explored and on the other hand, the reasons behind possible confrontation between these two major issues and suitable strategies for reducing the conflict, has been discussed and analyzed. Amongst the nine concept of aesthetic that affect social preferences, the concepts of complexity, coherence, imageability and ephemera in green spaces of arid regions, are faced with more challenges than other concepts. Since in the xeriscaping, use of drought-resistant plants is one of the principles so, for low diversity in ornamental plant species and partial removal of lawns and water element in the landscape, aesthetic preferences of citizens, will not be fulfilled completely. Social awareness toward the water crisis in the arid and semi-arid regions of Iran, ornamental plant domestication and import of drought resistant species as alternatives and also creativity and innovation in xeriscaping designs, can decrease the possible dissatisfaction of the citizens from the sustainable and rational development of green spaces in dry climates.

Zinnia (Zinnia sp) has long flowering period and is used as cut flower, pot plant and landscap desings.  The effect of different levels of phosphorus and vermicompost medium were studied on the vegetative and flowering characteristics of Zinna. Treatments consisted of phosphorus at three levels (0, 0.5 and 1 mg /kg) and vermicompost at three levels (0, 10 and 20% vol). The experiments were factorial based on a completely randomized design with three replications. Plants grown in greenhouse conditions for two months. The plants were then cut off from the crown and the leaves and stems were separated. Some of the traits measured included dry weight of the plant, chlorophyll content, vegetation index, root length, flowering stalk and flower diameter. The results showed that the use of phosphorus and vermicompost at higher levels had a significant effect the measured charcteristics. The highest diameter of flower was 5.5 cm and the maximum length of flowering branch was 32.5 cm in treatment of 1 mg/kg phosphorus and 20% vermicompost. Maximum chlorophyll a and b content, root and shoots fresh and dry weights and vegetation index were observed when vermicompost at level of 20% and phosphorus at levels of 0.5 and 1 mg / kg were used. In general, results indicated that use of vermicompost with phosphorus spraying improved the vegetative and flowering indices.

In order to produce superior genotypes through self- pollination of Gladiolus grandiflorus cv. Amsterdam, an experiment was carried out in a randomized complete block design (RCBD) with three replications in 2015 to 2018 at the ornamental plants research center in Mahallat city of Iran. Analysis of variance among genotypes showed significant differences in all traits. The results showed that genotypes of oprc46 in size of floret and oprc45 in vase life (10.33 days) were superior. The highest height of plant was observed in oprc49 (176.00 cm) and the highest number of florets were detected in the parent (16.5n). The color range of flowers in genotypes included; orange, red, pink, peach and varied combinations. In most genotypes, the perianth tube (main color of macule) had spots and with white, red, and orange color, which indicated the trait is dominant in genotypes. Evaluation of qualitative traits in genotypes showed that the most common arrangement of floret in spike was one row and most florets were star-shaped. The results showed that diversity in traits was mainly due to genetic factors and the environmental factors were less effective. The superior genotypes have the potential to be introduced as new cultivars.

Sexual regeneration is one of the important topics in silviculture that is based on seed production. Seed production is more important in oak, because oak seeds (acorns) are important source of food for animals and human. Zagros forests located along the Zagros mountains in western and southern Iran are covered with different species of oak and Brant`s oak (Quercus brantii</em> Lindl.) is the dominant species of these forests. Since acorn production ability of different oak trees is different due to differences in genetic structure and other influential factors such as site and climate, identification of good acorn producers is very important. In this research, 30 Brant’s oak trees were selected in a part of Poldokhtar forests in Lorestan province, Iran, and their acorn production were studied during 4 years (2014-2017) using crown count method. For sample trees, trunk and crown health characteristics, maturity, single-stem, minimum diameter of 15 cm and no touching of adjacent crowns were considered and their quantitative traits were measured. The two criteria were used to identify good acorn producers: trees that produce acorn each year and those that their average acorn production was higher than the average acorn production of the stand. Based on the results, the mean number of acorns of sample trees in 4 years was 476.6 and the lowest and highest acorn produced was zero and 5696, respectively. Also, only one tree had the characteristics of the good acorn producer. The results of this study showed that even with 3 years of acorn production monitoring, good acorn producers in Brant`s oak trees can be identified with acceptable accuracy . In this research, good acorn producers of Brant`s oak were identified in a part of the forests of Lorestan province.

African violet (Saintpaulia ionantha H. Wendi.) is an important ornamental plant due to its various colors and shapes. The present study was conducted to compare the in vitro and in vivo propagation methods in this plant. At in vitro culture, the interactive effect of five explant types (leaf blade, petiole, petiole without epidermis, whole inflorescence and flower without petals) and three cultivars (‘Cool Blue’, ‘Rondita’ and ‘Knight Rider’) cultivated on MS culture medium containing 0.1 mg/l NAA and 1 mg/l BA were investigated. At in vivo culture, leaf cuttings of three cultivars were cultured in wrapped plastic dishes contained 70% peat-moss and 30% perlite. Propagation speed and  number of buds in two methods were compared. Results showed explant type and cultivar effected the rate of regeneration significantly.  In cv. ‘Cool Blue’ there was not a significant difference in regeneration percent, bud production and number of leaves in all of the explant types. In cv. ‘Rondita’ the highest regeneration percent were observed in leaf blade (91.66%), petiole (91.66%) and petiole without epidermal (83.33%). Whereas in cv. ‘Knight Rider’ maximum regeneration percent (100%) was detected in leaf blade, whole inflorescence, flower without petals and petiole. The maximum (8.25) number of plantlets per explants in the in vivo method was observed in cv. ‘Cool Blue’ . Flowering time was significantly higher (180 to 230 days) in explants propagated at in vitro conditions compared to the ones propagated by in vivo method (120 to 140 days).  , However, the number of regenerated buds at in vitro culture were significantly higher than in vivo culture.

Application of suitable substrates is important for growing ornamental plants. Mushroom compost is considered as a waste in mushroom production. An experiment was done in a completely randomized design including the following treatments: substrates containing 50% cocopeat + 50% mushroom compost, 50% composted forest trees+ 50% mushroom compost, 50% perlite+ 50% mushroom compost, 50% leaf compost+ 50% mushroom compost and control substrate (70% agricultural soil+ 20% leaf compost+10% rice husk). The comparisons were carried out in 4 months; April, May, June and July and the the effect of different substrates were evaluated on the growing characteristics of Ficus benjamina</em> cv. Starlight.  The result showed the effect of substrate was significant on factors such as new leaf number, length and width of leaves while it wasn't significant on factors such as height, stem diameter and chlorophyll content. Also the effect of treatment time was significant on new leaf number, height, length and width of leaves, and stem diameter. The interactive effect of potting substrates and treatment time were significant on stem diameter, new leaf number, length and width of total leaves too. However, they weren't significant on plant height. Evaluation of results showed the best substrates for mixing with mushroom compost, were cocopeat, perlite and composted forest trees. Also growing indices were higher in plants that were treated in June and July compared tothe plant treated in other months. In conclusion, potting substrates such as perlite, cocopeat and composted forest trees in combination with mushroom compost are suggested to be used in the greenhouses.