پژوهشنامه اصلاح گیاهان زراعی
پیاپی 7 (بهار و تابستان 1390)

In order to evaluate relations between phonological trains, yield components and grain yield of 30 soybean lines with different maturity groups, an experiment conducted as a randomized complete block design with three replications at the agricultural research station of agriculture and natural resources research center, Gorgan, Golestan Province in 1388. 13 traits of vegetative and reproductive growth stages, yield components, seed protein and its oil content were evaluated. Number of days to flowering, number of branches per plant, number of pods on main branches, the number of days to maturity, yield components and grain yield had positive correlation and significant effect. Grain protein and grain shell weight ratio had a significant and negative correlation with grain yield. In the stepwise regression model,79% changes in seed yield by number of days to flowing, seed number per plant, number of branches per plant, seed protein percent and weight of shell: seed ratio and 21% of remaining by other effect could be explained. The 5 are mentioned characters were used to analysis. Results showed that most direct and positive effect on seed yield related to the number of days to flowing and the number of branches per plant.

Study of combining ability and heterosis were conducted on 12 F1 hybrids along with seven rice genotypes (three cytoplasmic male sterile lines and four restorer varieties) to know the pattern of inheritance of some morphological traits for selecting superior genotypes. The experiment was carried out according to line x tester mating design, in Sari Agricultural Sciences and Natural Resources University (SANRU) agricultural experiment station, during 2007-08. Analysis of variance revealed significant differences among genotypes, crosses, lines, testers and line x tester interactions for tiller number, plant height, days to 50% flowering, panicle length, number of spikelets per panicle, spikelet fertility and grain yield traits. Variances of SCA were higher than the GCA variances for traits except for plant height which indicated predominance of non-additive gene action nature of inheritance of the traits. The highest heterosis (106.60%) was observed in cross IR68899A x Poya followed by other eight crosses for yield and most of its related traits. The proportional contribution of testers was observed to be higher than that of the interactions of line x tester that revealed the higher estimates of GCA variance that shwon an additive gene action existing among the testers used. Within CMS parents, IR62829A and among male parents, IR50 and Poya were observed to be good general combiners for most of the characters studied. The cross combinations IR62829A x Mosa-tarom, IR68899AxPoya, IR58025AxIR50 and IR58025AxPoya were observed to be good specific cross combinations for grain yield and most of its related traits due to highly significant SCA and heterotic effects.

Physiological studies indicated that flag leaf has high contribution in wheat grain yield. In addition, number, distribution, and morphology of stomatal characteristics are important traits in the drought resistance and adaptation of wheat cultivars to fluctuating CO2 levels. A complete set of diallel crosses among seven durum wheat lines were used to study of genetic parameters of stomatal and flag leaf characterstics. Seven traits including stomata frequency, stomatal surface and stomata size in abaxial and adaxial of flag leaf, flag leaf length, width and area were measured. The analysis of variance revealed significant differences among genotypes for all traits. General combining ability variance was highly significant for all the characters and specific combining ability variance was highly significant for all the characters except flag leaf length and flag leaf area. The mean square ratio of GCA to SCA implied the importance of additive genetics effects in expression of flag leaf length and stomata size in the front and surface of the flag leaf. Reciprocal mean squares were significant for all traits. Diper-6 had the highest GCA effect for flag leaf area, flag leaf length and flag leaf width. The biplot showed the same result. The heritability in narrow sense was highest (0.27 and 0.21) for flag leaf length and adaxial stomatal surface. Base on narrow sense heritability, selection for flag leaf length and adaxial stomatal surface in primary generations could be successful in the genetic material.

Rice is a second important crop at Iran and its cooking and eating quality plays important role for consumers. In order to improve yield and quality, a set of crosses among Amol- l3 and Sepidrood made with Domsiah Mashhad and Sange Jo. (Amol- l3 and Sepidrood belong to improved and Domsiah Mashhad and Sange Jo belong to local varieties). The F1 is back crossed with local varieties as donor parents for two generation (BC2) and then handled upto BC2F5 generations. Thirteen promising lines with higher yield and quality were selected, their primary, advanced field and quality test done. Line DN-33-1 regarding to the yield and early maturity indicated better performance than Sang Tarom (check variety). This line with 123 cm height, tolerant to stem borer, resistant to blast disease and lodging including good physicochemical properties (Amylose content 23.4, gel consistency 89.1, gelatinization temperature 6.91, grain length 6.9 mm and chalk less) almost similar to local good quality varieties but 5.93 tons/hectare while the average yield of local varieties are around 3.5-4 tons/hectare.

In order to evaluate genetic diversity and determine genetic relationship of 64 Kabuli chickpea genotypes under late season drought stress, an experimental design was carried out in a simple lattice design (8×8) in 2011 on the research field of college of Agriculture and natural resource of Tehran University. Based on factor analysis, four factors were selected that in total 81 percent of the total variation was explained. The first and second factors were explained 64 percent of variation that including yield and yield component traits. Therefor these two factor used to identify genotypes with high yield and yield components and genotypes 2, 12, 22, 23, 36, 109, 120, 139, 187, 308, 335, 345, 357, 375, 474, 534, 563 and 629 with two control genotypes Jam (998) and korosh (999) were selected as high yield and component yield genotypes. According to the result of cluster analysis based on morphological traits, the genotypes were classified in 4 clusters. The genotypes of third and fourth cluster in most of agronomic traits and grain yield per plant had high average in compare with other clusters and genotype average. According to result of cluster analysis, we can use third and fourth cluster genotypes and two control genotypes (jam and korosh) for produce hybrids with early maturity and high yield.

Aloe vera L. plant have industrial applications in various fields of health. Leaves of Aloe vera are used for treating against infectious diseases, wounds, burns, skin allergies and are also used to prevent human hair loss. Propagation of this plant has traditionally done by planting its shoot tips. Since Aloe vera plant is male sterile, it cannot produce fertile seeds for cultivation. Outcrosses will change its genetic uniformity, in which supposed as a very important character in production of this genotype. Today, micro propagation method is extensively used for reproduction of Aloe vera. To provide optimum in vitro propagation method, adventitious shoot explants of this plant were cultured on agar solid MS basal medium supplemented with sucrose. Treatments used in the shooting stage include BA (2 mgl-1), Kin (0.5-1 mgl-1), NAA (0.2-0.5 mgl-1), IAA (0.1 mgl-1), IBA (0.25 mgl-1), BAP (1 mgl-1). Experiment was investigated sing a complete lyrandomized design. Results in shooting stage showed that the combination of BA (2 mgl-1)+ Kin (0.5 mgl-1)+BA (2 mgl-1) with mean of 10.66±1.36 in shooting stage and NAA (2 mgl-1) by mean of 4.8±1.16 in rooting stage produced the highest outcomes, respectively.

In order to study effect of G×E interaction on yield of genotypes in three environment. These genotypes were planted using RCB design with 3 replications in Esfahan, Kermanshah and Varamin. The results of combined analysis of variance for yield showed significant difference for genotype, location and G×E interaction effects. Because of significant G×E interaction stability analysis methods AMMI were used for determination of desirable genotypes for yield. Based on AMMI method, genotypes No. 5, 6, 11, 15, 16 and Marvdasht variety showed general adaptability and genotypes 17 and 18 recognized to have specific adaptability to Varamin and genotypes No. 4, 19 and 20 had specific adaptability to Kermanshah. Overall, based on stability analysis on yield genotypes No. 15, 16 and Marvdasht with having good adaptability were determined as desirable genotypes.