IRANIAN JOURNAL OF COTTON RESEARCHES
Year:2016 | Volume:3 | Issue:2 |Papers Count:7

For distinctness, morphological characteristics uniformity and stability evaluation of cotton, a research based on completely randomized blocks design conducted by four replications. Varamin, Sahel, Bakhtegan, Mehr, Oltan, Dr. Omoomi, Sepid, Pak, Khordad, Sealand, Armaghan, Golestan cultivars and No.200 genotype thirty nine morphological characteristics of their measured. Petal colour and base colour spot intensity qualitative morphological characteristics divided cultivars into two groups, Dr. Omoomi grouped in one group and others grouped in other group. Based on pollen colour Bakhtegan and Sahel cultivars in one group and others in other group settled. Pubescences of stem and plant form separate those cultivars into distinct groups. Oltan,Varamin, Mehr, Pak, Sealand, Khordad, Sepid, Armaghan and Golestan cultivars based on flowering type divided into three distinct. Boll longitude cut form distinct Mehr, Pak, Sealand, Armaghan and Golestan cultivars into three groups and Pak, Sealand and Golestan cultivars in one group and Mehr and Armaghan each in one group. Based on stigma position to anthers Pak and Sealand cultivars in one group and Golestan in other group settled Also on the basis of toothed bracts and boll shallow holes Pak and Sealand distinct each another. Leaf shape separated Varamin, Khordad and Sepid cultivars into two groups and Varamin and Khordad cultivars in one group and Sepid cultivar settled in other group. Finally by stigma position to anthers characteristic separated Varamin and Khordad cultivars and all cultivars separate from each other.Therefore, studied cultivars and genotype by9 qualitative distinct morphological characteristics identifiable from each others.

This study has conducted in order to investigate the impact of supportive price policy on the development of cotton acreage in Golestan province. For this purpose, time series data, ARDL and ECM models were used. Based on the results, although the impact of the increase of cotton relative price on its acreage in the short and long-term time horizons was significantly positive, but it is not substantial. So motivating farmers to increase cotton acreage requires a significant increase in its price compared with the price of wheat due to the cost load, making it will not be possible for the government practically. Therefore, relying solely on price policy supports in current form is not remedial and non-price supports for the realization of increasing cotton acreage and production is necessary. Based on the results, the impact of rice acreage on changes in cotton acreage in this province is negative as expected but this impact was not significant. The results also indicate that the prevalence of Canola acreage in Golestan province from the mid-seventy decade, did not affect the cotton acreage and it was not a competitor product. According to the adjustment coefficient (-0.64) in error correction model, if appropiative support price and non-price policies to be adopted, cotton acreage will return to its equilibrium amount in the short term.

To identify the drought tolerant genotypes an experiment was conducted in research farm of Faculty of Agriculture of Birjand University in 2014. Two separate experiments were conducted in a randomized complete blocks design with three replicates14 treatments. Cotton genotypes were: Armaghan, Oltan, Bakhtegan, Sahel, Si ecra, Shirpan 603, Khordad, Deltapine 25, Mehr, Varamin, N-200, SB35, SP371, 84-39-T3, respectively. Irrigations in normal and drought stress conditions were applied after 100 and 200 mm evaporation from class a tank. Comparison of different water stress indices showed that Stress Tolerance Index (STI), Mean Productivity (MP), Geometric Mean Productivity (GMP), Modified stress tolerance index for normal condition (K1STI) and Modified stress tolerance index for stress condition (K2STI) were the best indices that can be used to determine resistant genotypes. The most desirable genotypes at normal and stress conditions based on the above indices were Deltapine 25, Bakhtegan and SP731 respectively. Grouping of genotypes using cluster analysis method showed that Deltapine25, Bakhtegan and SP731 were water deficit tolerant genotypes with high yield and the SB35, N-200 and Si ocra genotypes were sensitive varieties to water deficit stress. Multivariate Biplot of genotypes confirmed the results of Classification of genotypes for identifying tolerant genotypes.

Cholesterol oxidase enzyme, as a new generation of biological pesticides, has pesticides strong effect on the pest to cotton Heliothis armigera. The mechanism of action of cholesterol oxidase fatality related to the oxidation of cholesterol in the membranes of insect midgut epithelial which leads to physical destruction and the resulting disturbances in membrane structure and function and eventually death of the insect. In order to retrofitting genetically engineered plants against pests, production of them with the gene coding for cholesterol oxidase enzyme, require the best method for expression level and activity of this enzyme. Therefore, this study aimed to clone cholesterol oxidase enzyme in plasmid pET23a for possible guidance recombinant protein produced in bacterial periplasmic space. Rhodococcus sp. strain 502 that produce high level of cholesterol oxidase, was used for gene isolation by PCR. The PCR product was sub cloned in plasmid pJET, subsequently for expression was cloned in pET23a, eventually was transformed into the host E.coli DH5a. Recombinant plasmid pET23a CHO was confirmed by restriction enzyme digestion and sequencing. The results of sequencing showed high similarity between our isolated gene sequence and the other cholesterol oxidase gene sequences in NCBI that can be used for production of biological pesticide.

Cotton bacterial blight is a important and quarantine diseases of cotton in Iran that appeared in cotton fields of Golestan province in 2005. Samples of infected leaves collected and served in room temperature. In 2014, sections from infected leaves washed with tap water, then were placed in a few drop sterile distilled water in room temperature for five hours. The suspension streaked on NA medium. After 48-72 hours isolated bacteria colonies yellow, circle and 1 mm diameter. The bacteria were negative in gram, oxidase and fermentative growth tests. All of isolates were positive oxidative growth and starch hydrolysis. The isolates used from glucose, inulin, urate, malonate, lactate and tripton but did not used from trehalose, L-rhamnose, D-raffinose, fucose, maltose, L.tartrate, D-galacturonate, acetate, nicotinate, glycine, casein, dulcitol, L-threonine, and adonitol. Isolates were variable in utilization of arabinose, D-fructose, D-xylose, melezitose, melibiose, guanine, L-cysteine, L-tryptophan, L-histidine, betaine, β-alanine, L-valine, D-sorbitol, citrate and L-maleate. In Pathogenicity test, bacterial suspension injected with sterile syringe into epidermis leaf of Golestan cotton cultivar. The water-soaked spots observed after 3 days that extended and revealed vein blight. The importance oftherole ofinfectedplant debrisin theincidence andspread of the diseaseisofparticular importance.

In order to choose the most suitable pesticide against, Creontidades pallidus, an experiment was carried out in a Randomized Complete Block Design with three replications and six treatments inGolestan province in 2003 and 2004. Plot size was 8 by 7.2 meter (nine 80 meter long rows spaced 80 centimeters apart). At each sampling, 10 randomly-selected plants were shaken into the net.. At the peak of bug activity in cotton fields, the experiment was done, and one day before and 2, 5, 7, 10 and 14 days after pesticides aplication, number of pests were counted. In two-year combined analysis, although, the effect of location by treatment interaction was significant for the traits, there were not any significant differences between locations. There was not any significant difference between pesticide for pest reduction rate at 2nd and 5th day after pesticides application, but treatment means for raw data was singinificantly different from the check. Based on two-year results, Danitol and Chess at Agricultural Research Station of Gonbad and Cotton Research Station of Hashem –Abad, respectivly had the highest effect on pest reduction (67.69 and 75.92 percent reduction, respectively). According to the conbined analysis of the data, Chess, Danitol, Metasystox, Admiral, Confidor were ranked first to five with 67.60, 63.21, 57.51, 54.13 and 34.51 percent reduction, respectively.

Cotton leaf spot disease caused by Alternaria alternata is one of the most common and important diseases in the cotton growth areas. The use of tolerant cultivars is one of the most economic means for the disease control. This study was conducted to evaluate the response of cotton cultivars against the fungus.In this research the fungus were isolated in seedling stage and purified in seedling stage from the cotton fields of Golestan province. and then fungus was detected using morphological data. Confirmed Alternaria species was performed using nucleotide sequence data of ITS – rDNA region and sequencing of the part of endo poly galacturonase gene. Accordingly, isolated Kb2 isolate with fungusA. alternata were in one group phylogeneticlly. The relative resistance of seven cotton cultivars consist of Sepid, Golestan, B - 557, Sahel, Thermus-14, Bakhtegan and Armaqan to A.alternata Kb2were evaluated in greenhouse conditions and seedling stage with completely randomized design in three replications.The results revealed that the reaction of cultivars to disease were different, however, none of the cultivars showed high levels of resistance. Termus- 14 cultivar had the highest of leaf spot severity and B-557 and bakhtegan cultivars had the lowest of leaf spot severity. In other words, these two cultivars were introduced as the tolerant cultivars to leaf spot disease at seedling stage.