فهرست مطالب

دانش کشاورزی - سال هجدهم شماره 3 (پیاپی 71، پاییز 1387)

فصلنامه دانش کشاورزی
سال هجدهم شماره 3 (پیاپی 71، پاییز 1387)

  • 264 صفحه، بهای روی جلد: 5,000ريال
  • تاریخ انتشار: 1387/11/15
  • تعداد عناوین: 20
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  • Smj Nazemosadat, Ar Gasemi, S. Aminand Ar Soltani Pages 1-17
    Seasonal prediction of dry and wet spells is critical for competent management of water resources in the rain-fed wheat region in western and northwestern parts of Iran. The present study has evaluated the effects of the Persian Gulf Sea Surface Temperatures (PGSSTs) on precipitation variability of these regions during warm (El Nino) and cold (La Nina) phases of the El Nino - Southern Oscillation (ENSO) phenomenon. The results indicated that, compared to single variable, the composite effects of the PGSSTs and ENSO enhances the prediction of winter precipitation. When warm ENSO phase is coincided with below normal PGSSTs, the probability of winter drought varies from 0.50 and 0.7. This probability drops to less than 0.33 if the PGSSTs are warmer than usual. Therefore, as El Nino is approached, above and below normal PGSSTs imply less and more frequency of dry spells, respectively. The coincidence of La Nina and colder than usual PGSSTs promises the prevalence of wet condition (for winter) over most parts of the study area and a productive situation is anticipated for the rain-fed crops. On the other hand, these crops encounter a high risk of water shortage if La Nina concurs with warm PGSST epochs.
  • F. Niazi, A. Fakheri Fard, A. Hoseinzadeh Dalir, Ah Nazemi, Ma Ghorbani Pages 19-31
    In order to optimum use of dam’s reservoirs, and regulation of the river and flood alert, forecasting of rivers discharge is of great importance. Rainfall- runoff is one of the complex hydrological process that depends on many factors, such as soil moisture, land use, geomorphology, evaporation and infiltration of catchments. In this research, the unit hydrographs resulted from geomorphological unit hydrograph of reservoir (GUHR) and Nash models for the Kamanaj bala catchment flood discharges, the catchment which located in Eastern Azarbaijan, were compared with the observed unit hydrographs. The criteria used for evaluation of the models include: coefficient of determination (R2), error in volume of hydrograph (V%), error in peak flow (QP%) and error in time to peak (TP%). According to the results both methods simulated peak flows smaller than those of observed. Nash model predicted time to peak earlier than the observed one, while GUHR model predicted it later. But generally GUHR model simulated peak flow and time to peak better than Nash model. The sensivity analysis of models carried out based on their parameters variation. Results showed that the hydrographs indicated high sensitivity to their parameters of related models.
  • H. Sadeghi, H. Mohammadi Pages 33-43
    Callus production potential and callus growth rate in the stem explants of five to 6-year-old Tehran pine (Pinus eldarica M.) were investigated in 30 different treatments of MMS culture medium. The experiment was carried out as a completely randomized design. Rusults showed significant difference between treatments at % probability level for the amount of callus produced. In addition results indicated that 2,4-D is an essential component for stimulation of callus production and is more effective than NAA. The increase of this hormone to the concentration level of 7.5 mg lit-1, caused increase in callus production but the growth rate of the callus in subsequent subcultures was higher in lower concentrations of this hormone. Furthermore, analysis of the callus growth data using multivariate regression showed a negative interaction between the concentration of 2,4-D and kinetin, since the increase in 2,4-D concentration caused more callus growth while at the presence of high kinetin concentration the lower growth in the callus was observed. However, this interaction between NAA and kinetin was not obtained.
  • S. Aliniaeifard, Sj Tabatabei, J. Hajilou Pages 45-56
    An experiment was conducted to find the effect of proline (Pro) and salicylic acid (SA) on some physiological parameters on olive grown in saline and non-saline conditions. The experiment consists of anti-stress chemicals (Pro, SA, and Control) factorially combined with two levels of NaCl salinity (0 and 100 mM) with four replicates. The results showed that Pro caused the increase of both fresh and dry weight of olive tree grown in saline conditions. The concentration of K and K/Na ratio in salt treated plants was increased when Pro was applied, while the concentration of Na was significantly reduced. Membrane stability index in salt treated plants was increased when Pro was applied, leading to the reduced electro-leakage. Salinity increased electro-leakage consequently the membrane stability in those plant were reduced. Relative Water Content (RWC) significantly reduced in Pro treatment in slat treated plants. The Highest and lowest RWC was obtained in SA and Pro treatment, respectively. Finally, exogenously application of Pro yields a higher total tolerance index compared with the control. It can be concluded that applying of Pro can to adjust the ionic balance, reduce ionic toxicity and maintain the integrity of cell membrane in saline conditions. Therefore, it should be possible to increase the tolerance of salinity of olive trees by applying Pro.
  • F. Fakhrzad_S. J Tabatabaei Pages 57-67
    An experiment was conducted with four KNO3 levels (0, 5, 10 and 15 mM) and two NaCl (0 and 60 mM) that factorially combined in a completely randomized design with three replicates to find the effect of salinity and KNO3 on the growth of turf. The results showed that the increased salinity significantly reduced the vegetative traits. In the saline conditions, increasing the KNO3 up to 10 mM increased the fresh and dry weight as well as leaf area. However, the growth of the plant was decreased at the 0 and 15 mM of KNO3. The reason for the reduced growth in the K0Na60 was due to the drying of the plants. The concentration of N, P and K was reduced in the salinity treatments but, the concentration of Na and Cl was increased. Salinity significantly reduced the K/Na ratio, while it was increased when the KNO3 was increased in the solution. The concentration of Cl wassignificantly reduced when KNO3 increased in the solution so that its concentration in K0Na60 was 58% higher than that in K15Na60 treatment. Proline content of the plant was not affected by the salinity treatment, however combination of salinity and high concentration of KNO3 remarkably increased the proline content. Applying salinity increased chlorophyll content but, in the K15Na60 treatment it was reduced. It seems that the reduced Cl, increased proline and K/Na ratio were the main reason for the improved growth of the turf in the 10 mM KNO3 in saline conditions.
  • M. Karimi, M. Hassanpour Asil Pages 69-81

    An experiment was carried out to evaluate vase life and quality of cut lilium flowers (cv. Romano) using five chemical solutions and two keeping temperatures by factorial experiments based on completely randomized design with three replications. At first, the cut lilium flowers pulsed with different chemical solutions treatments containing sucrose (3%), 8- hydroxylquinoline sulfate (200 ppm), citric acid (100ppm), gibberellic acid (50 ppm), kinetine (50 ppm) for 24 hours. Then, flowers were transferred into distilled water and maintained at 4°C or 22°C. The effects of applied treatments on vase life, total soluble solids, chlorophyll index, flower diameter and rate of water uptake were evaluated. On the bases of the results the effect of 4°C temperature with mean of 30.61 days on the flower longevity was significant (p< 0.01) higher then 22°C with mean of 10.5 days. Also, 4°C temperature showed better effects on other characteristics. Maximum flower vase life was related to treatment with gibberellic acid (36.33 days for 4°C and 13.3 days for 22°C) and increased the chlorophyll centont of the leaves. Minimum vase life was related to 8-hydroxylquinoline sulfate (25 days for 4°C and 9 days for 22°C). Citric acid and 8-hydroxylquinoline sulfate increased of water uptake and inhibited the vascular stopping.

  • Sf Kiaee Jamali, A. Forghani Pages 83-97
    In the tea gardens of Northern Iran, soil pH (has been decreased) due to several reasons (below pH of 4 in some regions). By-products of the steel industry, such as slag and converter sludge, that have an alkaline pH, might be used as a low-cost liming material for increasing soil pH, and as an amendment for these soils. A field experiment was established to determine the effects of these by-products on soil and plant chemical properties. The design consisted of 18 plots of 40m2 area, and 6 treatments (0.5% and 1% slag, 0.5 and 1% converter sludge, 0.5% slag + 0.5% converter sludge on a dry soil weight basis, plus a control treatment) with three replications of tea rows with a randomized completely block design. Materials of the six treatments were mixed with soil to a 15-cm depth in the spring. Two months after mixing, soil samplas were taken at five stages after 45-day periods and from 0-15 cm depth. Leaves plucking are performed in the spring, summer and autumn. Results showed that soil pH was increased with applications of slag and converter sludge. Soil pH was higher in the slag treatments than with the converter sludge treatments. DTPA-extractable Zn and Mn were significantly lower in all by-product treatments than that of the control treatment. DTPA-extractable Cu in soil in the 1% slag treatment was significantly lower than in the control treatment. There were no significant differences in DTPA-extractable Cd among all treatments and the control. Soil Fe in all treatments, except 1% converter sludge treatment, showed a significant decrease as compared with the control. Results of leaf analysis showed that Zn, Cu and Cd concentrations were decreased significantly in all of the slag and converter sludge treatments compared with control treatment. Plant concentration Mn in all treatments, except 0.5% slag and 1% treatments, were significantlylower than the control. Plant Fe concentrations in all treatments, except 0.5% slag treatment, were also significantly lower than the control.
  • Mr Neyshabouri, N. Safaralizade, S. Oustan, M. Tourchi Pages 99-112
    In the current study structural stability were determined using three methods of Kemper and Rosenau, Le Bissonnis, and Levey and Miller. The stabilities are expressed in terms of three indices as water aggregate stability (WAS), mean weight diameter (MWD) and stability ratio (SR), respectively. Nineteen soils with broad range of organic carbon content (OC), calcium carbonate equivalent (CCE), (ECe), SAR and texture were employed. purposes were to evaluate a) effects of the above soil parameters on three stability indices, b) to examine the limitations may rise practically in the measurements and c) to compare degree of agreement between the three indices. WAS varied from 6% to 89%; 64% of the variation (R=0.80**) resulted by the variation in OC. WAS was significantly and adversely affected by CCE (R=-0.62**) and SAR (R=-0.52*). In spite of wide variation is soil texture among 19 soils, it did not produced significant effect on WAS. Measurements of MWD in the examined soils dominant in clay fraction, were unsuccessful due to cementing of the particles after the weighing and ovendrying steps and, therefore, it was measured only in 12 soils where this problem was not occurred. MWD measured under three initial wetting conditions of the aggregates, namely, fast (MWDf), slow (MWDs) and slow with shaking (MWDsh) were slightly different and their mean differences were insignificant (P<0.05). Due to simpilicity and rapidity of measurement, MWDf appears sufficient enough as a stability index of Le Bissonnis method and there seems no need for the measurements of MWDs and MWDsh. MWDf ranged from 0.32 to 1.17: Soil OC attributed to 84% (R=0.91) of its variation, implying that MWDf basically was dependent to OC. In contrast to WAS, MWDf was not statistically correlated to either CCE or SAR, but instead was significantly affected by sand (R=0.74**) and clay (R=-0.61**) contents of the soils. It, therefore, appears that using MWDf as a stability criterion for the comparision of structural stability among soils would be justifiable if the main variant among them is texture rather than chemical charactercs such as CCE, EC or SAR. SR ranged from 0.29 to 0.89 (theoritical range is 0 to 1.) and its response to soil parameter variations was quite similar to MWDf. Among the three indices, there was more close agreement (R=0.87**) between SR and WAS than between MWDf and WAS (R=0.71**). Using SR, 12 examined soils could be grouped in three qualitative structure stability classes namely highly stable (SR≥0.81), moderately stable (0.42
  • Ar Vaezi, Ha Bahrami, Shr Sadeghi, Mh Mahdian Pages 113-123
    Water has a vital role in increasing crop yield in dry farming lands in semi-arid regions. This study was conducted to determine factors affecting runoff and develop an equation for predicting the runoff in the dry farming lands. The study was conducted in the Hashtroud, located in south part of East-Azarbijan province in northwestern Iran, from March 2005 to March 2006. A square network of dry farming lands with 900 km2 area was selected and divided into 36 regular grids with a dimension of 5 km. In each grid, runoff plots with dimensions of 22.1 m in length and 1.83 m in width at three replicates and 1.2 m spacing were prepared on a dry farming land with a slope 9%. At the lower parts of the plots, runoff-collecting equipments were established. Rainfall properties were determined on the basis of recording rain gauge data of a meteorological station. Based on results the runoff in the plots was affected by 23 natural rainfall events during the study period. The soils of the study area are mainly clay loam with a moderate infiltration rate and having almost 1% organic materials and 13% lime. Runoff amount per rainfall event varied frame 2.153 to 49.377 liter per plot. Runoff negatively correlated (r= -0.85, p<0.001) with soil infiltration. The results indicated that the runoff can be easily predicted using a linear regression equation based on coarse sand, organic matter and lime (R= -0.84, p<0.001). Coarse sand, organic matter and lime significantly increased soil infiltration and consequently reduced runoff.
  • B. Behtari, A. Dabbagh Mohammadi Nasab, K. Ghassemi Golezani, S. Zehtabe Salmasi, M. Toorchi Pages 125-135
    A split-plot experimental based on randomized complete block design with three replication was conducted in 2004 at the Research Farm of the Faculty of Agriculture, University of Tabriz, Tabriz, Iran. The effects of limited irrigations on yield and yield components of two soybean varieties (Zane and Huck) in the field were investigated. Irrigation treatments were assigned to main plots, and two soybean cultivars were allocated to the subplots. Irrigation treatments I1, I2, I3 and I4 were defined based on the cumulative evaporation of 60±3, 80±3, 100±3 and 120±3 mm, from pan (class A), respectively. The results indicated that the mean number of leaflets, branches, pod-bearing nods, pods and grain per plant, plant height, grain weight, biologic and grain yield of plants for I1 were comparatively higher than other irrigation treatments. All these traits were decreased with increasing water stress. Although, the harvest index was achieved under I1, but this superiority was not significant, compared to other irrigation treatments. Mean 100 grain weight of Zane was higher than Huck, but Huck produced comparatively more branches, pod-bearing nods, pods per plant, grains per plant and consequently more biologic and grain yield. Positive and significant correlation of number of grains per plant with grain yield per unit area and non-significant correlation of mean grain weight with grain yield indicated that in this study grain per plant of soybean was more effective on grain yield than the mean grain weight.
  • P. Safari, R. Honarnejad, M. Esfahani Pages 137-147
    In order to study and evaluate selection indices in peanut varieties, an experiment with 39 peanut varieties was conducted in 2006 as a randomized complete block design with three replications at the Tobacco Research Institute. For formation of selection indices, four traits were selected by means of stepwise regression. In this study two kinds of selection indices were used: optimum and base indices. Economic weights that used included: unit [1], phenotypic correlation [rp], genetic correlation [rg], direct effect in path analysis, heritability and first factor loadings in factor analysis. The comparison of selection indices efficiency showed that genetic advance and correlation of optimum selection index with genotypic worth was more than the base index. But, because of proximity of genetic advance in base index and optimum index and simplicity of calculation of base index, it can also be used for selection. For both base and optimum selection indices the weight of one and factor loadings as economic weights would improve peanut oil yield. On the basis of calculated selection indices three varieties [ICGV 92118 (25), ICGV 92040 (17) and ICGV 93134 (20)] were selected as the best varieties.
  • B. Mahdavi, Modarres Sanavey Pages 149-160
    In order to study the effect of different root-zone temperatures (RZTs) on nodulation and nitrogen fixation of some grasspea ecotypes, a factorial experiment based on randomized complete block design with three replications was conducted in a controlled-environment chamber in 2006. In this experiment, three ecotypes of grasspea, Ardabil, Sharhkord and Zanjan were used. Four root-zone temperatures (5, 10, 15 and 25°C) and constant air temperature (25°C) were considered. The results showed that there were significant differences among the grasspea ecotypes for nodulation and nitrogen fixation. Zanjan ecotype produced the highest nodule number at 15°C RZT, while Ardabil ecotype had similar nodule number at 25°C. Zanjan ecotype had the lowest nodule number at 5°C. Ardabil and Zanjan ecotypes had the maximum and minimum nodule diameter at 10 and 5°C, respectively.The highest nodule dry weight belonged to Ardabil ecotype at 25°C. Zanjan, Ardabil and Shahrkord ecotypes were not significantly different for nodule dry weight at 5°C. The maximum nitrogen concentration and forage protein was obtained from Ardabil ecotype under 25°C. Zanjan ecotype had the lowest nitrogen concentration and forage protein at 5°C. All ectypes had the highest nodulation and nitrogen fixation at 25°C and the 5 and 10°C RZTs reduced nitrogen fixation and nodulation of studied ecotypes.
  • Af Mirlohi, R. Mohammadi, Sj Razavi, F. Norbakhsh Pages 161-171
    Land preparation for rice cultivation especially in the form of puddling could be destructive to soil structure and reduce the yield of crops. This study was conducted to compare the effects of soil puddling, submergenceand rice cultivation with normal tillage, nonsubmergence and corn cultivation on barley yield as second crop. Also the residual effects of six fertilizer treatments including two levels of organic manure, three applications of urea, and a check were evaluated. The experiment was conducted as split plot in a randomized complete block arrangement with three replications. Rice and corn were allocated in the main plots and the fertilizer treatments in subplots. Fertilizers were applied to each plot according to first year randomization and their effects on barley growth, as the second crop, were studied each year and average of three years. Barley seeds of Valfajr variety at 200 kg/ha were sown after rice and corn harvest in both plots applying similar tillage system. Analysis of variance revealed a significant difference among fertilizer treatments for seed yield, plant dry weight, number of tillers and plant height. Mean comparison of these traits between the main plots (rice & corn) showed higher values for barley planted in corn plots. Although not statistically significant, the barley seed yield was about 1 ton/ha higher in corn plots. Application of organic fertilizers in the previous crop significantly increased the barley yield, especially in the plots that received the highest quantity of manure. Also split application of urea in three increments in rice and corn plots had a significant improvement on barley yield as compared to the treatment that received all urea at once at the beginning of the cropping season.
  • M. Besharati, A. Taghizadeh, H. Janmohammadi, Ga Moghaddam Pages 173-185
    Food by-products in Iran are produced by milling, and other food processing industries. There are several methods to evaluate feedstuffs. In this study, in situ and in vitro gas production techniques were used to describe nutritive value of grape pomace, raisin waste and grape stalk. For this purpose two ruminal fistulated sheep were used. Nylon bags which were approximately (6×12 cm) containing 5g samples (2mm screen) were incubated in duplicate in the rumen of fistulated sheep for 0, 2, 4, 6, 8, 1, 16, 24, 36, 48 and 96 h. The gas production was recorded after 2, 4, 6, 8, 12, 16, 24, 36, and 48 h of incubation. The data at the different times was analyzed using completely randomized design. Dry matter disappearance of grape pomace at 24 h was higher than grape stalk (60.73%) and raisin waste (58.07%). But at the same time CP disappearance of grape stalk was significantly higher than grape pomace (56.64%) (P<0.05). The gas production volume at 24 h for grape stalk, grape pomace and raisin waste were 209.17, 231.66 and 180.88 mL/g DM, respectively, and among feedstuffs grape pomace had the highest gas production volume (p<0.05). The results indicated that in situ technique has a suitable correlation with gas production volume.
  • H. Janmohammadi, H. Nassiri Moghadam, J. Pour Reza, M. Danesh Mesgaran, A. Golian Pages 187-197
    Metabolizable energy value of six samples of meat and bone meal was studied with 35 adult leghorn roosters (1868± 63/02 of average body weight) with seven groups of five roosters in a completely randomized design. One group attended for determination of endogenous energy loss. Nitrogen balance was negative among meat and bone meal samples and the differences was not significant but energy balance corrected to zero nitrogen point showed significant difference (p<0.05). The values of metabolizable energy including AME, AMEn, TME and TMEn showed significant differences among the meat and bone meal samples. Mean and range of AME, AMEn, TME and TMEn values were 2686 (2200 to 2987), 2755 (2237 to 3010), 3183 (2692 to 3484) and 2993 (2473 to 3253) Kcal/Kg, respectively. Gross energy efficiency (TMEn/GE) varied from 0.623 to 0.674 and showed significant differences among samples (p<0.05). The mean value of apparent and true digestibility of dry matter in meat and bone meal were 34.9 and 51.6 percent. The dry matter digestibility values showed significant differences (p<0.05) among meat and bone meal samples. Significant negative correlation of ash obtained with AMEn and TMEn content of meat and bone meal (r= 0.90 p=0.0138, r= 0.87 p= 0.0224, respectively). Significant correlation of Gross energy with AMEn and TMEn (r= 0.96 P=0.0024, r=0.94 p=0.0039) was also observed, respectively. Multiple regression analysis of TMEn on chemical composition content of meat and bone meal by stepwise procedure showed that gross energy content of meat and bone meal was the only predictor variable of TMEn, with coefficient of determination of 0.92 (p=0.0023).
  • Sd Javaheri, Gh Tahmasbi, Sa Mirhadi Pages 199-208
    In order to find the most suitable substitute for the pollen at the time of scarcity in the nature and also to prevent the weakening of the colonies, an experiment was designed with six dietary rations consisting of pollen substitute and pollen supplement using soybean meal (treatment 1 and 2), pollen substitute and pollen supplement using corn gluten (3 and 4), pollen substitute and pollen supplement using sesame meal (5 and 6) and control group using only sugar syrup (7). This experiment was conducted with 70 colonies. Feeding of colonies was carried out in three steps from beginning of autumn till the end of the winter using cake of 550, 350 and 500 grs. respectively. In order to evaluate the effect of these experimental diets on body composition, several variables such as total nitrogen content of bee head and thorax (mg/bee), average dry weight (mg/bee), dry matter and moisture content of the head and thorax (%) of the nurse bees were measured. The results indicated that difference in nitrogen content of heads and thoraxes of nurse bees fed by different experimental rations were statistically significant (p< 0.01) and ration 2 has statistically significant difference with others, so the highest values of heads and thoraxes were belonged to ration 2, and the lowest values were obtained for rations 1, 3 and 6, respectively. For average dry weights of heads and thoraxes of nurse bees the ration was significant higher than others (p<0.01), and the lowest values belonged to rations 6 and 4, respectively. In terms of the average dry matter the rations 2 and 1 had significant differences with others (p< 0.01) and the highest values for heads and thoraxes were belonged to these rations, and the lowest values to rations 5 and 6. Also for percentage of average moisture content the rations 5 and 6 were significantly for heads and thoraxes and the lowest values belonged to rations 2 and 1, respectively. It was concluded that the two protein rations 1 and 2 were more palatable and more effective on body composition of nurse bees and can be used as nutritional stimulants during scarcity of pollen which will result in early laying, supplying the nutritional requirements of these bees, improving the growth of hypopharyngeal glands of worker bees and increase royal jelly secretion for feeding of queen and the larvae.
  • Sh Mohammadnezhad Kiasari, H. Barimani Varandi, A. Borhani Sar Mosavi Pages 209-221
    Design of exotic softwoods adaptation in the form of randomized complete blocks design with 3 replications and 8 treatments (species of needle leaves) has performed from ten years ago in the low land forestations of Neka forests (Kohsarkandeh). As the most important cause of the damaged trees in this design was wild pigs (Sus scrofa L.), so our study in this paper is about this animal. The results of this research showed that Pinus teada with average of 20.33 damaged trees in 300 m2 (% 22.17) and pinus radiata with average of 13.67 damaged trees in 300 m2 (% 20.62) were the most damaged trees between our treatments. This investigation has been done with full inventory of all trees. The Analysis of PCA showed that some of characteristics of single damaged trees and some of characteristics of various softwoods stands have influenced in the quantity of damaged trees by wild pigs (Sus scrofa L.). The treatments of Pinus teada and Pinus radiata with best quantity and quality growth and with the high average height of natural pruning caused increasing the damaged trees by Wild pigs. The treatment of pinus nigra with average quantity and quality growth, The low average height of natural pruning and with high percentage of viability caused decreasing the damaged trees by wild pigs. The treatments of Pinus roxburghii and Cedrus deodara with average quantity and quality growth and with low percentage of viability caused decreasing of the damaged trees by wild pigs.
  • A. Nobakht, A. Tagizadeh Pages 223-231
    This experiment was conducted to evaluate the effects of reduction or withdrawal of mineral and vitamin supplements from diets of laying hens at 70 to 78 weeks of age on performance and egg quality of laying hens. One hundred and ninety two Hy-Line strain laying hens, were randomly assigned to four dietary treatments. The levels of minerals and vitamins supplements were 0.25, 0.19, 0.13 and 0 percent and fed to laying hens for eight weeks. There were not any significant differences in performance and egg quality between experimental groups. The overall results of the present study indicated that it is possible to remove dietary mineral and vitamin supplements from laying hens diets in late laying period without any adverse effects on performance and egg quality.
  • H. Irandoost, Gh R. Niknam, A. Ghasemi, M. Taghavi, E. Turabi Pages 233-242

    In order to study genetic diversity among East Azarbaijan and Fars provinces isolates of Ralstonia solanacearum, samples were collected from potato fields. A total of 35 bacterial isolates from East Azarbaijan province, three isolates from Fars province and one isolate from infected tubers of Karaj market were isolated from potato samples. DNA fingerprinting with two rep-PCR primers (BOX and Rep) was performanced on selected isolates including five isolates from East Azarbaijan, three from Fars, one from Karaj market and two from Costa Rica as standard isolate. The length of produced fragments ranged from 200 bp to 1200 bp in BOX primer and 200 bp to 1500 bp in Rep primer. The grouping of isolates using UPGMA method and Jaccard`s coefficient which obtained from combined molecular data of the both primers grouped the isolates of R. solanacearum in two distinguished clusters. Group one included Fars isolates biovar N2 and group two consisted of eight biovar 2A. The results of this study indicated that rep-PCR technique with two Rep and BOX primers is capable to show differences among biovars 2A and between biovar 2A and biovar N2 as well as genetic polymorphism among different populations of R. solanacearum.

  • M. Yazdanian, R. Farshbaf Pour Abad, Mr Rashidi, M. Valizadeh, N. Rashtchi Zadeh, A. Mansour Vatankhah, Aa Hamidi Pages 243-259
    Studying insect digestive enzymes is important for understanding the function of their digestive systems. Nowadays, many attentions have focused on plant enzyme inhibitors and their application for producing transgenic plants. Determining the properties of all digestive enzymes is the first step that should be executed. In the case of beneficial insects, digestive enzyme activators would be of great importance. In 2004, some properties of salivary α-amylase of the stripped bug, Graphosoma lineatum was investigated for the first time. The experiments were repeated four times. Enzyme was active at 25 to 50 °C and its considerable activities were observed at 25 to 40 °C. However, the highest activity occurred at 37 °C; so, its optimum temperature was 37 °C. Enzyme activity decrease at pH4, 4.5 and 10 in relation to the elongation of incubation period (30-110 minutes). At pH5 to 9.5, enzyme was active throughout the incubation period without any decreasing. At pH10.5, enzyme was active until 30 minutes after incubation; and at pH11, the enzyme became completely inactive. Optimum pH for enzyme activity was 6.5. There was a linear relationship between enzyme concentration (2-25 pairs of salivary glands per one ml of buffer solution) and its activity. Enzyme activities in phosphate buffer (41.53 U/mg protein), Ringer’s infusion (42.52 U/mg protein), 5% dextrose (43.10 U/mg protein) and distilled water (41.63 U/mg protein) solutions were statistically similar, but significant difference was observed between its activity in 96°C (40.06 U/mg protein) and 75°C (14.07) ethanol solutions. Preservation of the enzyme solution at 4°C for 40 days had no effects on its activity.