نشریه روابط خاک و گیاه
پیاپی 10 (تابستان 1391)

Salinity and waterlogging are two important abiotic stresses to plants growth and yield in the world. These two stresses can occur simultaneously and have additive effects on plants، including corn، growth. In a greenhouse experiment، the effects of NaCl salinity and waterlogging and their interactive effect on the growth characteristics of forage corn (Zea mays cv. single cross 704) were studied. A factorial experiment on the basis of completely randomized design with three replications was performed with two factors of waterlogging period at five levels (0، 2، 4، 8 and 20 days) and soil saturate extract salinity at four levels (0. 11، 2، 4 and 8 dS/m). The results showed that the effect of salinity level on fresh and dry weight of shoot and root، ratio of fresh weight of shoot to that of root، leaves chlorophyll index and plant height was significant. By increasing the level of salinity، the fresh and dry weight of both shoot and root، chlorophyll index and plant height were decreased significantly. The effects of soil waterlogging period on fresh and dry weight of shoot and chlorophyll index of leaves were significant but were not significant on fresh and dry weight of root، ratio of shoot fresh weight to root fresh weight، and plant height. By increasing the duration of soil waterlogging، the wet and dry weight of shoot and root، ratio of fresh weight of shoot to that of root، chlorophyll index and plant height were decreased significantly. The interactive effects of salinity and waterlogging on shoot fresh weight and leaves chlorophyll index were significant but were not significant on other measured characteristics. The highest shoot fresh weight was obtained in control treatment and the lowest amount of it was observed in salinity level of 8 dS/m and 20 days after soil waterlogging. The corn shoot growth was more sensitive than its root to salinity and waterlogging stresses. The results demonstrated that even short periods of soil waterlogging (2 days) had considerable long-term effect on the growth characteristics of forage corn.

Recently، great emphasis has been placed on using soilless media in greenhouse culture for evaluation of plant nutritional efficiency. A factorial experiment، in a completely randomized design with three replications، was conducted to categorize wheat genotypes according to their Zn acquisition efficiency (ZACE) and Zn utilization efficiency (ZUTE). To study the Zn acquisition and utilization efficiencies، calculated Zn efficiency (CZE) and shoot Zn efficiency (SZE)، 20 wheat genotypes (Darab، Hirmand، Bayat، Kaveh، Navid، Dez، Sholeh، Golestan، Aria، Azadi، Rasoul، Marvdasht، Atrak، Inia، Karaj-1، Karaj-2، Moghan-1، Shiraz، Nik Nezhad and Hamoon) were grown in sand culture that was supplied with nutrient solution including Zn (5 mg/kg) and without Zn (0 mg/kg). The results showed that wheat genotypes were varying in shoot Zn efficiency، root and shoot Zn utilization as well as acquisition efficiency. Hamoon genotype was the most Zn-efficient and Hirmand was the most Zn-inefficient genotype under zinc deficiency condition. Shoot ZUTE showed significant relation with ZE and Hamoon (Zn - efficient) and Hirmand (Zn-inefficient) showed the highest and the lowest shoot ZACE، respectively. Furthermore، Navid (3. 67%) and Inia (3. 98%) genotypes contained the lowest and Marvdasht (10. 58%) the highest shoot ZUTE. Results showed that there was significant relationship (P<0. 01) between ZE and CZE. Marvdasht (643%) and Aria (158%) genotypes had the highest and the lowest CZE among other genotypes، respectively. In general، in greenhouse environment، uniform and regular use of nutrient solution can meet factors required for screening and selection of resistant genotypes to Zn-deficiency.

Considering the increasing trend of saline land enhancement and lack of appropriate agricultural lands، identifying salt resistant plants such as fenugreek، which is an important medicinal plant، is important. To do so، a factorial experiment was conducted in the form of randomized complete blocks design with three replications on three fenugreek landraces (Yazd، Shiraz and Hendi) and five salinity levels (0، 40، 80، 120 and 160 mM NaCl) in hydroponic culture in greenhouse of College of Agriculture، Shahrekord University. The results showed that plant height، root length، shoot dry weight، root dry weight، and number of leaves per plant was reduced with the increase of salinity level. Increasing salinity level led to an increase in the amount of Na+ in shoot dry matter، while the amount of Ca+2 and K+ and Ca+2/Na+ and K+/Na+ ratios were decreased. The Yazd cultivar had the highest mean plant height (20. 1 cm)، shoot dry weight (1. 94 g per plant) and number of leaves (13. 4 per plant). Whereas، Shiraz cultivar had the highest amount of Ca+2 and K+ ions and also Ca+2/Na+ and K+/Na+ ratios. Based on the results of this research، it seems that Shiraz landrace، carrying genes related to salinity tolerance could be used to improve high yielding genotypes.

Appropriate plant nutrition has a great impact on yield and yield quality of crops. To optimize nutrition of broccoli in calcareous soils، poor in organic matter content، a pot experiment was conducted in greenhouse of Zanjan University in 2010. With respect to nitrogen (N) and boron (B) deficiency in calcareous soils and great impact of these elements on yield and quality of broccoli، the effects of different rates of these elements on head yield and head quality of broccoli were assessed. The experiment was factorial، with completely randomized design، and had 15 treatments and three replications. Treatments were factorial combinations of five rates of N (0، 100، 200، 300 and 400 kg/ha from ammonium sulfate source) and three rates of B (0، 1. 7 and 3. 5 kg/ha from boric acid source) that were applied to Sakura cultivar of broccoli. The results showed that application of N and B up to a specific rate increased head yield and quality of broccoli. Application of 300 kg N/ha + 1. 7 kg B/ha resulted in the highest yield of broccoli head، but higher N and B rates decreased head yield due to enhancement of head rot and plant toxicity. The highest concentration of N، potassium and magnesium in broccoli head was measured in treatment with 400 kg N/ha + 1. 7 kg B/ha.

Periwinkle (Catharanthus roseus L.، Apocynaceae) contains more than 130 different terpenoid indole alkaloids (TIAs)، of which two dimeric alkaloids، Vinblastine and Vincristine، have antineoplastic activity and are useful in treatment of various cancers. Specific production of some alkaloids in differentiated tissues such as leaf and stem led to use direct regeneration of explants in order to increase the production of these important alkaloids in the plant. In this research، 30 combinations of plant growth regulators and activated charcoal were used in MS media for direct regeneration of node explants. Application of BAP in media containing 1 g/l activated charcoal showed the best direct regeneration of node explants and shoot proliferation. Although application of activated charcoal is necessary for periwinkle growth in media due to many phenolic compounds، but it has negative effects on adsorption of plant growth regulators and consequently reduce shoot proliferation. Therefore، it seems that 1 g/l activated charcoal is an appropriate concentration for preparing shoot proliferation media. In addition، transporting regenerated shoots to culture media containing NAA resulted in increasing shoot length. Proliferated shoots rooted in media without PGR and with 2 g/l activated charcoal and acclimated with environmental conditions after transferring to the soil.

Potato (Solanum tuberosum L.) is one of the most important economical vegetable. Minitubers are small seed tubers without pathogens that are produced from invitro plantlets after translocation to greenhouse and create healthy and high quality seed tubers. Hydroponic systems increase the production of virus-free potato minitubers. This research was carried out to study the effect of different growth media on number of minitubers and concentration of elements in potato shoot and root and also to compare the hydroponic culture and soil containing media in a randomized complete blocks design with 8 treatments and 4 replications. The treatments consisted of: 1) perlite، 2) perlite + vermiculite (1:1 v/v)، 3) perlite + peat moss (1:1 v/v)، 4) perlite + soil (1:1 v/v)، 5) perlite + soil + compost (40:30: 30)، 6) perlite + soil + vermicompost (40:30: 30)، 7) soil، and 8) perlite + peat moss (control). At the end of growth period، the number of tuber per plant and concentration of elements (N، P، K، Na، and Ca) in roots and shoots were measured. Results of analysis of variance showed that bulk density، particle density، porosity، EC and pH of different growth media were significantly different (P<0. 01). The soil medium had the highest bulk density (1. 23 g/cm3)، the highest particle density (2. 44 g/cm3)، the highest EC and pH and the lowest porosity (50%). Therefore، this treatment produced the lowest number of tubers per pot. The maximum concentration of N، P and K in potato shoot and root were in perlite + soil + vermicompost and soil + compost + perlite media. The maximum concentration of Ca in potato shoot was in perlite + soil medium (1. 68 mg/g dw). The maximum concentration of Na in potato shoot was in soil + compost + perlite medium (0. 35 mg/g dw). Number of minitubers and plantlets’ growth in soilless media (hydroponics) were higher than soil media. There were significant correlations between the concentration of elements in root and shoot with the properties of cultivation media. The perlite + peat moss medium (1:1 v/v) is recommended for hydroponics production of potato minitubers.

Zinnia is one of the beautiful and attractive flowers due to its length of blooming period and various colors. The effects of phosphorus (P) and vermi-compost and zeolite media on some growth characteristics and chemical composition of Zinnia were studied in a greenhouse experiment. Treatments consisted of 3 phosphorus levels (0، 5 and 150 mg P per kg soil) and 3 zeolite and vermi-compost levels (0، 5 and 10% w/w)، that were arranged in a completely randomized design with 3 replications. Plants grew for two months in the greenhouse. Then، they were cut from collar and leaves and stems were separated. Leaf area، chlorophyll content، fresh and dry weight of plants، dry weight of leaves، dry weight of roots، and concentration of P، zinc and iron in the aerial parts of the plants were measured. The results showed that vermi-compost treatment had the highest amount of growth parameters and the differences were significant as compared to control and other treatments. Zeolite decreased the studied plant growth parameters as compared to the control; the least amount of growth parameters belonged to zeolite treatment.

It pays attention to cultivation greenhouse، and provides produce artificial condition and the variants environment have especially important for neutralizing in progressing extent agriculture processes. It is necessary for progressing we need suitable planning until we can move forward to producing program and we are needed to know about variants and limitation which obstacle the develop of this plantation. It is based on this research، general object for recognizing important variants than the useful management of the summer greenhouses in Khuzestan province do it. This research is a kind of usage and it conducted by measurement method in Khuzestan province. We use for gathering information from questionnaire achieve and interview method. In the research of the statistical social. There are 95 unite of the summery greenhouse of province. In order to، experts use of panel method for determining validity. They divided 30 the kind of the questionnaire and then gathering them، they calculate score 11. 5 of kourenbakh (α) coefficient by SPSS software. This coefficient calculates for 2 parts، sustainable agriculture and skillful knowledge are %71 and %82 respectively. The results of research showed that age، courses studies and experience of owner`s greenhouse can make important differences in optimum management level. And also There are statistical significant relationship between the skillful knowledge of the owner`s greenhouse and their perception to sustainable agriculture with useful management. Additionally، education level couldn''t affect on optimum management in summery greenhouses.

Cadmium (Cd) is a heavy metal which is toxic to human، plants and all other organisms. Among heavy metals، Cd mobility and phytoavailability in soils is of great concern due to the fact that even at low concentrations may cause toxicity. Thus its behavior in soils needs further investigation. A greenhouse experiment was carried out to examine the effect of Cd and two zinc (Zn) sources (sulfate and chelate) on spinach growth and some nutrients concentration، in a factorial arrangement based on a completely randomized design. The treatments consisted of three Cd levels (5، 10 and 20 mg/kg soil as cadmium sulfate) and four Zn levels (0، 5، 10 and 20 mg/kg soil either sulfate or chelate) in three replicates. The results indicated that Cd application significantly decreased dry weight of spinach while Zn decreased the adverse effects of Cd. Increasing Cd level increased the concentration of this element in spinach shoot. Both sources of Zn significantly decreased Cd concentration in spinach aerial part. Cadmium application significantly decreased Zn and manganese (Mn) concentration in spinach shoot، but had no significant effect on iron (Fe) concentration. Both Zn sources decreased Mn and Fe concentration in spinach shoot. Based on achieved results of this study، it seems that Zn fertilizers application، especially Zn-sulfate، is useful to reduce the adverse effects of Cd on plants in soils contaminated with Cd.