نشریه فنآوری تولیدات گیاهی
سال نهم شماره 2 (زمستان 1388)

So far، extensive research projects have been sort out to study effects of drought stress on the plant antioxidant enzymes activity، while there is some information lacking of such studies on the field condition. In the present research project، total protein content and enzymes activity of superoxide dismutase (SOD)، ascorbate peroxidase (APX)، catalase (CAT) and peroxidase (POX) were analyzed under water shortage stress using spectrophotometer and gel assay procedures on a randomized factorial design for five inbred lines of barley. Amount of total protein was significantly increased under water shortage، whether amount of chlorophyll decreased. Activity of SOD and CAT، POX were significantly increased under water shortage stress. Level of enhancement in the activity of POX was more intensive for watering plants than drought stress plants. Also increased activities of POX and SOD were significant under drought stress in comparison to rain fall condition. The kinetic assays were confirmed by isozymic analysis of gel assay. Results indicated that among all studied enzymes، activity of APX was low and didn''t have important role in plant protection under water stress، whether POX might have a key role as important enzyme to increase tolerance to drought stress in Hordeum vulgare inbred lines. Also، such activity of enzymes is suggested that different isozymes might be induced and exhibit activity depends on the water shortage stress level in barley.

Cumin (Cuminum cyminum) is an annual plant from Umbliferus family that is cultivated in Iran as landraces. This plant is one of the oldest plants with pharmaceutical and economical importance. In this experiment cumin seeds were collected from Khorasan، Kerman and Fars provinces of Iran. Explants were cultured in Gamborg media with hormonal components. Factorial experiment with four factor based on completely randomized design (CRD) was conducted. Factors that used in this experiment consist of three hormones، i. e. NAA with three levels 0. 2، 0. 4 and 0. 6 mg/L، IAA with two levels 0. 2 and 0. 4 mg/L and BAP with two levels zero and 0. 1 mg/L concentrations، and cultivar with three levels (three cumin landraces). The results showed that each of landraces produced hard، compact and white greenish color calli. After subculturing، embryogenesis stages consist of globular، turpido، heart and cotilidonary shapes were observed. Then thiny shoots were produced by embryos. Elongated shoots were cute from callus and transferred to rooting media with 1/2 MS salt and 0. 2 mg/L IAA. All of the shoots produced roots successfully. Fully developed plantlets with well-developed root and shoot systems were transferred to pots containing sterile sandy soil. After 20-30 days، the plantlets started to flowering. No albino or abnormal plants observed. The analysis of results showed that Khorasan landrace at hormonal component with 0. 4 mg/L IAA+ 0. 2 mg/L NAA + 0. 1 mg/L BAP had the maximum callus production and plant regeneration.

This experiment was conducted to determine the most important effective component on grain yield of rice and share of assimilates، remobilization of each section of shoot organs on grain yield with 10 genotypes of rice on the base of randomized complete block design with 3 replications in Rice Research Institute (Amol-Mazandaran) in 1383-84. The genotypes included of 8 new lines and two cultivars، Fajr and Neda. Some criteria were studied such as 1000- grain weight، number of grains in punicule، number of punicules per area unit and number of grains per surface unit as yield components and share of assimilates remobilization of each shoot organs such as stem، flag leaf، other leaves and leaf area index at flowering stage. According to the results of variance analysis، rice genotypes had significant difference (P≥0. 01) in the point of all criteria except of grain weight and mature grain percent. Among genotypes، line 106 and line 104 had the highest and lowest grain yield، respectively. Line 106 in comparision to other genotypes had highest average of 1000- grain weight، number of punicules per area unit and number of grain in punicule. It had high percentage of mature grains، too. Also، high leaf area index at flowering stage in this line caused to increase remobilization during grain filling. The results of this research showed that 1000- grain weight and number of punicules per area unit have high correlation with yield. So، it is possible to use them to choose superior genotypes to improve grain yield.

Proliferation of different plants is need for micropropogation and its in vitro studies. Optimizing and maximizing shoot proliferation is a basic objective of micropropagation and much attention has been focused on components that used in the culture medium and type of medium. Gami Almasi is a dwarf rootstock of apple (Malus domestica Borkh) that grow on North West of Iran and suitable for different cultivars of apple. In this study two different basal medium containing N6 and MS salts with different biochemical components involve Phloroglucinol (PG)، active charcoal (AC) and Gibberellic acid (GA)، was tested on proliferation and shoot elongation. In vitro growing shoots were used for these experiments. In results MS medium was better than N6 in apple proliferation case. Active charcoal hasn''t any effect on in vitro proliferation. Phloroglucinol as a phloridzin derivative have significant effect on proliferation. Phloroglucinol induced the transient proliferation in first month after culture and GA induced stable proliferation of shoots. The combine Phloroglucinol at 80 mg/l and GA at 2 mg/l have the best results in proliferation of apple shoots. Results from in vitro experiments indicated enhanced proliferation of apple shoots and also the occurrence of hyperhydric shoots was lower in the Phloroglucinol medium. Active charcoal has not significant effect on proliferation of apple.

Iran is on of the rich genetic resources of Persian walnut. Using the genetic variation of this gene pool for identifying and introducing new promising genotypes and cultivars counts as a first step of breeding programs. Molecular methods has provides a new opportunity for genetic study of plant varieties. Considering many advantages including high polymorphism and co-dominant mode of inheritance make Simple Sequence Repeat (SSR) as ideal markers in cultivar identification and study the genetic relationship of populations especially in allogam heterozygote plants like Persian walnut. In this study، the genetic diversity and structure of four Persian walnut (Juglans regia L.) populations including 28 genotypes in hamedan province was studied using 11 SSR markers. In total، 47 polymorphic alleles were detected. The average of observed alleles was equal to 4. 3 in each locus. Hardy-Weinberg (HW) equilibrium was not detected in most of the loci that could be related to selection pressure and natural selection in different climatic conditions. The highest genetic distance was found between Tuyserkan and Malayer populations and lowest genetic distance was found between Tuyserkan and Serkan populations. Cluster analysis based on Nei similarity coefficient matrix using UPGMA method classified the populations into two main groups. Classification of populations based on molecular data did match with their geographical situations.

In order to study bulblet formation of mooseer from stem disc explants two separate experiments were conducted. In the first experiment، the effect of two concentrations (0. 5 and 1 mg/L) of naphthaleneacetic acid (NAA) and deferent levels (0. 5، 1، 2 and 3 mg/L) of benzyladenine (BA) and in the second experiment، the effect of sugar source (sucrose and common sugar) and sugar concentration (30، 45، 60 and 90 g/L) were tested. All of explants were culture in MS medium. Results showed that in media without BA no bulblet were generated and just callus were produced. The highest numbers of bulblets (4. 65) were observed in 2 mg/L BA and 1 mg/L NAA which had no significant difference with 1 mg/L BA and 0. 5 mg/L NAA (4. 55). The biggest bulblets were produced in 3 mg/L BA and 0. 5 mg/L NAA which had no significant difference with 3 mg/L BA and 1 mg/L NAA. The standard (MS medium without hormones) had the least number of bulblets. In second experiment the effect of sugar source and combination effect of sugar source and sugar concentrations were not significant on bulblet production. This showed that common sugar can be use instead of sucrose. By increasing sugar concentration up to 60 g/L bulblet production increased. The lowest number of bulblet was observed in 30 and 90 g/L sugar. In highest concentration of sucrose bigger bulblets were produced compare with other treatments