Year:2005 | Volume:65 | Issue:4 (65 IN AGRONOMY AND HORTICULTURE)|Papers Count:18

Arabidopsis thaliana is a favorite model plant for biotechnology studies by which a remarkable development happened in plant sciences including plant breeding during the last decade. Inducing useful mutants, resistant to various environmental stresses, their recognition and transferring to other plant species, lacking the resistance, is one of the major applications of the species. Resistance to herbicides is one of the characteristics, which is very attractive to the breeders. This research was carried out to investigate the inheritance mode of the factors controlling resistance to uniconazol (a GA-biosynthesis inhibitor). Forty-eight variable gene pools created through inserting T-DNA to the genome of the Colombia ecotype of the species were received from Prof. Cutler from Toronto University, Canada, and used in this research to identify the uniconazol resistance genotypes. Twelve concentrations of the herbicide were tested on the Colombia ecotype to find the critical dilution ofuniconazol on which no wild type seed can germinate and grow. The gene pools were screened on the critical dilution and a number of the resistant seedlings were recognized. To investigate their gene function and the number of genes controlling the character, one of the mutants was crossed to the wild type Colombia and Landsberg ecotypes. F1 and F2 generations were also generated. Testing the parents and the two F1 and F2 generations on the critical dilution of the chemical, revealed that one dominant gene is controlling the character in the mutant.

In present research, allelopathic potentials of essential oils of Zhumeria majdae leaves were studied. Effects of different concentrations of essential oils on seed germination and seedling growth of, Lepidium sativum and Echinochloa crusgalli were studied. Besides, effects of essential oils on the leaf chlorophyl content, fresh and dry weight of root and stem and peroxidase activity in roots of 21-days seedlings above plants in post-emergence treatment were investigated. Essential oils prepared from leaves of Zhumeria majdae inhibited seed germination and seedling growth drastically. In the presence of 50 and 100 percent of stock solution, seed germination rate was reduced to zero. The activity of peroxidase enzyme, fresh and dry weight and chlorophyl content were reduced in all post-emergence treated plants.

Indigenous olive trees we dominant type in Roudbar olivet of Guilan province. The Roudbar's variety is cultivated in new olivet of Iran. One of The important characteristic of this variety is an alternate bearing, which this phenomena in orcharding economic aspect could be undesirable., whereas flowering habit has more affixes on alternate bearing & so considerable to study the effectiveness factors of lowering habits and alternate bearing of native olive trees. Therefore spraying by gibberlic Acid ir> form of random complete block design (RCBD)with 7 treats and 4 repetitions on selected branches of low productivity olive trees with 1.5 up to 2 meters long. Within periods of 2, 6, 10, 12, 18, 22 weeks after FB(Fool bloom) in 2000 (ofi year) in 200l(on year), ouring flowering, the number of flowers in inflorescence, complete flowers percent, diameter length and stone weight of sprayed branches counted. The results shown that spraying olive trees by gibbertic acid during different periods of the off year have different cfTeci on flowering characteristics and fruits as well (on year). Spraying in 18 and 22 weeks after FB time in off year did not observed significant difference in number of flowers on inflorescence compare with control trees. Spraying about 2. 6. 10, 12 wycks after flowering caused significant increasing in the number of flowers in inflorescence. Spraying by gibberlic acid during low rainy year could less effect un complete flowering and spraying about (2,6, 10, weeks after flowering caused low significant on fruit set percent in compare with conlnil treea- Spraying about 2,6, 10, 14 weeks after F.B time cause increasing and decreasing of fruits weight and pulp respectively. Spraying about 2, 6, 10 weeks after FB caused significant increasing in length and diameter in seeds in compare with control trees. Spraying has got significant effect on stone.

This study was conducted to evaluate the effect of different irrigation management (Viz., irrigation after; 0, 3, 6, 9- day after disappearing water from plot surface, and control treatment was continuous irrigation) , as a field experiment of factorial design in RCBD with 3 replicates was performed at rice research institute (Rasht, Iran) in 2001, to evaluate on seed yield, yield components, W.U.E. and some morphologic and physiologic characters in two rice cultivars (i.e. Binnam and Hassani). After transplanting and during anthesis, all plots were submerged, fori 0 and 15 days, respectively, and during the rest of stages, irrigation treatments were applied as were planned. The results showed that there was no significant difference among seed yield, biological yield and harvest index. So that, 9-day irrigation management (IS) decreased yield only 17 %. compare to control treatment (non-significant decrease), as saved water was about 50%. There was a significant difference among number of tillers, panicles, percentage of unfilled rains, W.U.E. and different irrigation treatments (p£1%). Moreover, there was a strong correlation between seed yield and seed number in panicle (r = 0.619**). In this study, despite the non-significant interactive effects between irrigation management and cultivar, the Binnam cultivar with average seed yield of 3097.6kg/ha and 9- day irrigation management with W.U.E. of 817.5g/m3 was found to be the best treatment combinations.

Harmful effects of chemical control of mulberry pests and disease for silkworm rearing will make the selection of high resistant plants to play a magnificent role on improvement of sericulture actives. Recognition and propagation of high disease resistant varieties of mulberry will prompt the quality and quantity efficiency of mulberry leaf as exclusive feeding resource for silkworm rearing and improve cocoon and silk output consequently. Mulberry powdery mildew is knownas one of the most important fungous disease all over the world. During this study in gat 2000-2001, Phyllactinia guttata was recognized as pathogen of disease in Gilan and 4 improved mulberry varieties i.e. KM, KN, I and SI as well as one local variety have been studied at Pasikhan site of Iran Sericulture Co. First year evaluation was based on natural contamination of 625 leaves of each variety selected from 25 trees as a colon. At second year, after relative expansion of disease from the most susceptible areas of Gilan (Roudbar and east zones) the infected leaves were collected and washed in 0.78% Glucose solution. The prepared suspensoid with concentration of 2x105 conidia/ml were sprayed on isolated sapling of each 5 varieties (each variety 10 sapling). After 10 days KM variety showed the first symptoms of disease under greenhouse conditions. 5 leaves of each tree were surveyed after full expansion of disease under natural condition and contamination level was coded based of 0-7 scale. Severity index (S.I. or PDI) during two years in spite of slight differences showed the following fashion: SI< I < KN< Local< KM. Chemical analysis of normal and infected leaves from the aspect of qualitative parameters such as protein etc. showed decreasment (sometimes increasement) in infected leaves in each variety which was corresponded with the mode of severity index of varieties.

In present study a marine isolate of Aspergillus niger was isolated from Caspian sea (Assadi and Tavasolei 1995), was used. The isolated fungus was exposed to DV radiation for different period of time, thus 99% of cells were killed. Decolorization potential of DV exposed colonies compared to wild type isolate. The results showed that there is different decolonization rate among mutants and between mutants and wild type strains. The mutant strain numbers 63(13.68%) and M.49 (94%) showed minimum and maximum decolonization rate, respectively, whereas wild type strain showed 67% decolonization rate. Approximately 2 g dry weight of mycelium was used to decolorize one liter of effluent.

The genus Festuca L. belongs to the tribe Poeae R. Br. (=Festuceae Dumort.) and to the family of Poaceae. Because of their well adaptation to the different environmental conditions and pasturage value especially F. ovina, many botanists have frequently studied these plants. In this research, different populations of the species F. ovina, in view point morphology and anatomy, were either collected from various regions in Iran, during the years 1999-2001, or obtained from several different herbaria of Iran studied here. Statistica software was utilized to perform cluster analysis on row data (17 OTU with 17 morphological characters and 17 OTU with 14 diagnostic anatomical characters). The results of cluster analyses reveal close relationship between F. sulcata and F. ovina. This confirms the opinion of Parsa in Flore de L Iran and Boissier in Flora Orientalis who had suggested the F. sulcata to be a subspecies (infraspecific relations) of F. ovina. The morphological similarities among the populations of these two species further confirm this finding and the species of F. ovina must be as an aggregate species with subspecies taxa in Iran. Finally, our results were compared and discussed with the results of others authors.

Saffron samples collected 16 regions of Khorasan province were investigated For existence of contaminating microbes. Staphylococci, Gram- negative bacilli, fungi and yeast were observed to exist on collected samples .The levels of contamination were counted, over 105, 103, 8x103 for bacteria, fungi and yeasts respectively. To reduce the contamination levels affron samples were irradiated with 2, 4, 6, and 7 KGy the higest decrease in contamination level was obtained with 6KGy, however at 7KGy contamination reached zero. Spectrophotometric analysis showed no change in colour quality of saffron samples. Aroma differentiation by saffron experts indicated no change in treated samples compared with the check.

Producers and consumers of patch crops notice to more supply with an favonible quality of this crops to market, recently. there for, it is necessary to find appropriate ways of producing plants with a high quality degree for supplying more revenue for producers and responding consumer demands. In current survey, the economic influence of polyethylene mulches application as a new technology on cucumber cultivation has analyzed then, a survey research with simple random sampling of cucumber producers in Isfahan province as survey society was used for this subject. Price information of degree of cucumber were collected from Isfahan vegetable and fruit organization in harvest period. In order to determination of these mulches effect on yield, an experiment split plot design used in four blocks r with superdaminous cucumber hybrids in Kaboutar-Abad station during 2000-2001. main factors were soil cover in three levels including block polyethylene mulch(BPM), transparent polyethylene mulch(TPM) and no polyethylene mulch(NPM). sub plots were sowing methods in two levels involve of unilateral plots(UP) and bilateral plots(BP). The information of first and second degrees of fruit yield in above factors was registered. according to economic analysis, the priority of treatments were:1- tpm in bp 4- npm in bp2- tpm in up 5- bpm in up3- bpm in bp 6- npm in up

Thermal asymmetric interlaced polymerase chain reaction (TAIL-PCR) in which asymmetric annealing temperature is used was employed to discriminate sequences flanking T-DNA insertions in Arabidopsis thaliana. In this method, left and right border sequences of the T-DNA insertions were regarded as the two tagged positions and two series of primers differing in length and annealing temperature were used to amplify the target sequences. The technique uses a series of nested primers specific to the known sequence of the left and right borders of the T-DNA and a series of shorter arbitrary primers with lower annealing temperature. Four mutants of Arabidopsis thaliana resistant to uniconazol (a GA-biosynthesis inhibitor), due to T-DNA insertions in their genome were studied in this research. TAIL-PCR was performed in three stages which in the second and third stages, diluted PCR products of the first and second stages were used respectively as the DNA template. In each stage of the TAIL-PCR a combination of five arbitrary primers and two specific primers for left and right borders of the T-DNA were used to amplify the target sequences in the four different mutant DNA samples. In other words, forty different reaction conditions were prepared and performed simultaneously. Investigating the PCR products of the second and third stages on 2% agarose gel and comparing the mutants bands related to the two stages, specific PCR products were detected and separated from non-specific products. Selecting the suitable bands with appropriate size, Qiagene kit was used to purify the PCR products and sequenced. Conforming the obtained sequences to the T-DNA left and right borders, indicated that the method amplified the targeted sequences with a high accuracy.

In the present research, the structure of sporophytes in following five species of mosses of northern Iran (Table 1) were studied: Atrichum crispum (Polytrichaceae), Orthotrichum rupestre (Orthotrichaceae), Schistidium martimum (Grimmiaceae), Tortula norvegica (Pottiaceae) and Funaria hygrometrica (Funariaceae). In the sporophyte structure, the type and shape of capsule, operculum, the length of seta, peristome form and the shape and size of spores were evaluated and compared with each other. Therefore, all the five species determinated and grouped in five families. Also correlation between the peristome and spore forms recognized. In some species, peristomes are made up of one and in others two rows. Peristome teeth in certain species are papillose and are not branched, while in other are branched and cilliated and not papillose. Spores in some species have smooth surface, some carying chloroplasts, while in other have either small or large papillae. When comparing spore surface and the shape of peristome teeth in various species there seems to be a mechanical compatibility between papillose and cillia for distribution of more spores of sporangium.

Rosa damascena Mill. from rosaceae family is cultivated in different parts of Iran, and its essential oil and rose water in large scales are produced. In this study, essential oils were extracted by hydrodistillation method. Nine genotypes samples from Isfahan province collected and cultivated in experiment field of Research Institute of Forests and Rangelands. Samples were analyzed by GC and GC/MS. The main constituents in Kamoo (with for samples) were phenylethyl alcohol (8.5 - 20.3%), citronellol (15.5 - 21.2%), geraniol (5.6 - 20.3%) and n- nonadecane (18.7 - 27.9%) and in Ghahrood (with one sample) were phenylethyl alcohol (15.2%), citronellol (12.8%), geraniol (12.7%) and n- nonadecane (25.5%) and in Ghamsar (with two samples) were phenylethyl alcohol (7.1 - 17.5%), citronellol( 99.5 - 17.7%), geraniol (6 - 13.3%) and n- nonadecane (25.5- 31%)and in Mashhad Ardehal (withtwo samples) were phenylethylalcohol(4.5- 10.3%), citronellol (13.9- 20.7%), geraniol (10.9- 18.4%) and n- nonadecane(23.6 - 25.5%).

Calcium ion has important effects on physiological processes of plants and improves the morphological and biochemical parameters of the plant which is under salt stress. Salt stress because of ion toxicity and interference with nutrients, affects parameters such as seed germination, root and shoot dry weight, quantity of proteins, proline accumulation, lipids peroxidation and others. Plants are able to use calcium ion to improve their efficiency under salt stress. How much they can use calcium to compensate losses during stress depends on their efficiency. In this experiment, we used Descurainia sophia L. plant which is a highly sensitive plant to salt stress. Plants which were grown in vermiculite in control room (temperature 23°c, humidity 44%, light 8.23 Klx) were treated with salts (0,25,50,75 and 100Mm NaCl) either with or without 5 and 10mM calcium. After 8 weeks under such treatments, all parameters were measured and analysed with SPSS Version 9.0. Results showed that the optimal concentration of calcium for maximum resistance depends on plant species and salt treatments that used. For most parameters, 10mM Ca2+ concentratin was toxic and 5mM concentration of this ion improved parameters in salt stress condition. Salt stress because of osmotic effects and Na+ toxicity, decreases plant growth and change plant parameters quantities. The threshold of this plant to salinity, is 50Mm NaCl. Salt stress beyond this threshold, significantly improved which plants were treated first with Ca2+.Our conclusion is using the plants with high CaER, can decrease economical expenses of plants in response to salt stress and improve growth efficiency.