پژوهشنامه اصلاح گیاهان زراعی
پیاپی 9 (بهار و تابستان 1391)

This research, was conducted in a population of 103 doubled-haploid (DH) lines, their parents and 5 Iranian local bread wheat cultivars, at three ys (2007-2009) in the field as triple rectangular lattice (10×11) designs. The results of AMMI analysis for grain yield per unit area showed: effects of year, genotype and their interaction effect were significant (P<0.01) indicating the significant effect of these factors on grain yield. The first two AMMI scores (IPCA) accounted for all (59.23 and 40.77%, respectively) of genotype-by-environment interaction effect variation, which was of interesting and valuable. The results of cross-validation with FR Cornelius, implied the usefulness of AMMI2 model, by which biplots of genotypes and environments averages plotted related to main components, categorized all genotypes in 3 classes. Furthermore, six superior genotypes selected along all the environments, that could be selected as the parents of crosses in breeding programs.

Mutation induction has been accepted as a useful tool in plant breeding programs to provide maximum inheritable variability. In present study، role of three chemical mutagens [Ethyl Methan solfonate (140 mM)، Sodium Azide (2 mM) and a combination treatment of Methyl Nitros ourea+ Sodium Azide (30 mM+2 mM)] for creating variability in Tarrom Mahali cultivar have been investigated. The measured agronomic characters were: Plant height، tiller number، length and width of flag leaf، panicle length، number of first and second spikelet، number of unfilled، filled and total seeds per panicle. Results indicated that plant height and number of total seed per panicle showed the best response to this mutagens because plant height decreased significantly in all mutagen treatments compared with control. Number of total seed per panicle increased significantly in all mutagen treatments compared with control. Plant height in three mutagen treatments showed the most heritability and genetic advance. Maximum heritability and genetic advances were belong to combination treatment MNU+AZ in most traits، therefore، it is indicated that effects of this mutagen is higher than the other two mutagens.

In order to investigat e of Tobacco germplasm genetic diversity، 49 genotypes were grown in Tobacco Research Institute (Rasht، IRAN) as a simple lattice design 7×7 with 2 replications and 12 treatments were evaluated as well. Correlation analysis to studied traits showed that Fresh leaf yield with leaf number، leaf length، leaf width، leaf area index، plant height، flowering period and days to flowering had positive and high correlation. Also correlation of dried leaf yield with other traits except flowering period was positive. Stepwise regression analysis showed that only two traits: fresh leaf yield (X1) and leaf numbers (X2) were affected on dried leaf yield significantly. Thus، direct effect of these two traits on dried yield were calculated 0. 5 and 0. 47 respectively by Path analysis. The stepwise regression analysis showed that plant height (X1) and leaf area index (X2) had highly significant effect on fresh leaf yield and they were considered as second step of dry leaf yield.

Different characters influence the marketing of rice in which aroma، amylose content، gelatinization temperature، gel consistency and grain shape are the most important ones. Two local quality (Shastak and Domsia) and two improved rice varieties (Nemat and Fajrr) were used to pyramid the qualitative genes into new released Ghaem variety through classical methods and marker aided selection. Ghaem variety was used as a recipient parent and crossed with others mentioned varieties. Then، composite crosses were made between F1 and after growing single plan، phenotypically desirable individual plant were selected. Followed by molecular analysis were used for study on segregation and combination of target genes using linked markers. The results indicated that Ghaem/ Domsia// Ghaem/ Shastak and Ghaem/ Nemat// Ghaem/ Fajr are the suitable crosses due to having most of the qualitative controlled genes، particularly aroma and grain shape. Mean while it is recommended that the final figures come out after doing advance generations and study the promising lines.

In the present research the effect of culture system، type and size of alternative bioreactor on micpropagation and microtuberization rate of potato (Solanum tuberosum L.) cv. Agria were investigated. Two kind of stable and alternative systems along with two type of bioreactors in 5 and 1 lit sizes were used. Single node stem segments from in vitro potato shoots were inoculated on liquid medium (MS medium) supplemented with 0. 5 mgl-1 GA3 and %3 sucrose for propagation and 10 mgl-1 BAP with 8% sucrose for microtuberization were applied. A completely randomized design with three replications was used. After 4 and 8 weeks number of nodes، shoot length، fresh and dry weight for determination of micro propagation rate and number and weight of micro tubers were recorded. Results were shown growth and tuberization rate، were depended on system culture. Result illustrated that this system is more benefit than common system and the highest number of nods and tuber were obtained in using alternative system. Also both types of bioreactors were effective for mass propagation for reduction cost، energy and handle work. However، the bipartite bioreactor was more effective than the other one because pollution and medium exchange for induction of micro tuber stage was simple. In current study the results indicated that by increasing capacity of bioreactor the vegetative and tuberization rate were increased and it was directly related to high frequency and time consuming especially in alternative system. In present investigation 450 micro tuber in the alternative bioreactor with 3000 ml culture media and 50 initial explants (9 micro tuber per explants) were obtained.

Estimation of genetic variation is very important in breeding programs and existing of high genetic variation lead to increase the response to selection. The objective of this study was to investigate genetic variation for agronomic traits and yield components in 20 entries of sesame including 15 breeding lines and 5 local populations. The genotypes were evaluated in a randomized complete block design with three replications at the research farm of Isfahan University of Technology. The results of analysis of variance showed that there were significant differences among the genotypes for all of the studied traits. Seed yield/plant, seed yield/plot and seed oil content of the genotypes varied from 13.02 to 35 g, 1297 to 3239 kg/ha and 39.35 to 57.19%, respectively. The range of days to emergence and maturity, plant height, capsule length, capsules/plant, seed weight, seeds/capsules among the genotypes were 4 to 8.3 days, 139 to 172.7 days, 116.5 to 150 cm, 2.2 to 3.2 cm, 64 to 129 capsules, 0.454 to 0.637 g and 69 to 110 seeds/capsules, respectively. High broad-sence heritability and low difference between genetic and phenotypic coefficients of variation was found for all of the studied traits, except for days to emergence. The highest and lowest genetic and phenotypic coefficients of variation were observed for branches per plant (64.15 and 65.72%) and days to 50 percent flowering (2.14 and 2.37%) respectively. Cluster analysis classified the genotypes into two distinct groups of 6 and 14 genotypes.

To achieve the high level of gene expression، promoters are key elements. Patatin promoter has been used as a specific gene expression in potato tubers. Patatin is a group of glycol protein in potato tuber which is code by a multiple family genes. This protein makes up more than 40% of soluble proteins of potato tubers. Class I Promoters mainly responsible for tuber -specific expression pattern of proteins and located high amount in tuber parenchyma tissue s. The purpose of the present study is the cloning and expression assay of tuber specific promoter، patatin class I (pat1). Total DNA of the potato tissue samples was extracted and the pat1 promoter was amplified using specific primers and pfu polymerase by polymerase chain reaction (PCR). The fragment was isolated by two restriction enzymes (BamHI، HindIII) and was replaced with CaMV35S promoter in pBI121 vector. The recombinant plasmid was transferred to Agrobacterium tumefaciens LBA4404 strain using freez-thaw method. The specific expression of gus gene in potato tissue was evaluated using agro-infiltration method. The results of the this experiment confirmed the specific expression of the gene.

In this research the effects of cold were evaluated on coleoptile growth of 18 rice genotypes in two separate experiments. The first experiment was carried out as factorial based on randomized complete block design with three replications. In this experiment، two factors were including genotypes at 18 levels and temperature at 5 levels (9، 13، 17، 21 and 25 C°). The seeds of genotypes don’t germinate at 9 C°. The length of coleoptile was measured in plantlets at the end of using of each temperature factor. Analysis of variance revealed that the effect of temperature، genotype and interaction effects of two factors were significant on length of coleoptile at 1% probability levels. The low temperature treatments decreased the growth of coleoptile in all of the studied cultivars. Taichung and Sadri showed a significantly bigger coleoptile length at the three low temperature treatments including 13، 17، 21 and 25 C°. The percentage of coleoptile reduction was calculated form comparison of the length of coleoptile at 13 and 25 C°. The coleoptile reduction rate was lower than 10 percentages in Hashemi، Gerde and Neamat، indicating these varieties as tolerant varieties to cold stress. Second experiment was carried out on randomized complete block design with three replications. In this experiment، the seeds were placed in 25 C° for 72 h and then the temperature was adjusted to 10 C° for 96 hr. Temperature was further increased to 25 C° and treated plantlets to this temperature for 72 h. The length of coleoptile was measured in two stage contain after 10 C° for 96 hr (length 1) and 25 C° for 72 hr (length 1). The difference between these two lengths were calculated and called coleoptile regrowth. Analysis of variance indicated that the effect of genotype were significant on coleoptile regrowth. Gerde was as a tolerant variety due to percentage of reduction in coleoptile length and coleoptile regrowth.