An experiment was conducted on the F1 generation from a half-diallel set of crosses involving two drought tolerant (Roshan and Kal-Haydary), three moderately tolerant (Bayat, B.C Roshan and Nick-Nejad) and three sensitive (Ghods, Falat and Darab2) genotypes of wheat to study gene action of rate of water loss (RWL) from excised-leaf, initial water content (IWC), air-canopy temperature difference (DH=Ta- Tc) at booting and anthesis stages, and leaf water potential (LWP) and leaf osmotic potential (LOP) at the anthesis stage of development. Highly significant differences were observed between genotypes for all traits except for IWC (at booting) and DT (at booting and anthesis at 10-11 h). General combining ability (GCA) and specific combining ability (SCA) mean squares, and GCA/SCA ratios were significant for all traits, noting the importance of additive gene action. Non-additive gene action had a major role in DT at anthesis. Narrow sense heritability ranged from 46% for DT at anthesis to 72% for RWL at booting and anthesis stages. Heterosis was not important for any trait. The genotype Kal-Haydary was the best general combiner for all traits except for DT anthesis in which Roshan was better.

In 1999 and 2000, 10 varieties and lines of bread wheat of different degrees of resistance and susceptibility to cold, were crossed in a half - DIALLELE scheme. The plant materials were cultivars Boulani, Sabalan, Khalij, Bezostaya and lines 591, 592, 273, 746, 581 and 583. The 10 parents and their 45 F1 hybrids were planted in greenhouse as well as field, at the College of Agriculture University of Tehran, Karaj, Iran. The traits of days to flowering LT50, survival at - 8°C, -12°C, -16°C, membrane stability (electrolyte leakage) were assessed. Membrane stability (electrolyte leakage) of the plants was found at -12°C. Results of ANOVA showed significant differences between genotypes in 1% and 5% levels of probability. Analysis of general combining ability (GCA) and specific combining ability (SCA) through Griffing method indicated significant differences between genotypes. It was found that genes with additive as well as non - additive effects control these traits. Graphic interpretations of the results of DIALLELE cross, by using Hayman's method revealed that dominant genes with additive effects control cold resistance. It was found that resistant cultivars Bezostaya and Sabalan bear a large number of Dominant genes, whereas other cultivars Bolani, Khalij as well as lines 746 and 518 carry mostly recessive genes.

In order to estimate gene action of yield and yield components characteristics such as Spikelet Number per Spike, Biomass Weight, Kernel Number per Spike, Seed weight of 10 spikes, Hectoliter Weight, 1000 kernel weight and Yield, six genotypes of bread wheat such as: Arvand, Atrak, Zarrin, Karaj-3, Mv-17 and Navid were used in a 6×6 half-diallel cross. The crosses among the parents were down in 2009-2010. The experiment was conducted in a randomized complete block design with three replications at the research station Mahidasht Kermanshah, Iran in 2010-2011. Data were analyzed using diallel method. Analysis of variance showed significant differences (P<0.01) among the genotypes for all studied traits. Regression coefficient and epistasis tests showed fitness of additive-dominance model for most of the traits except grain yield, 10 spikes weight and seed weight in 10 spikes. Results of Hayman analysis showed that contributions of additive and non-additive effects were involved in control of the traits. Hayman’s graphical analysis showed that A and B parameters were significant at 1% levels. The highest and the lowest heritability of traits belonged to hectoliter weight and 1000 grains weight, were 57% and 13%, respectively. Regarding presence of additive effects for understudy materials and cumulative effect of genes help early generations, screening of cultivars and it, in turn may improve yield and its components.

Fusarium head blight (FHB), caused by plant pathogenic fungi of the genus Fusarium, is a major disease of wheat (Triticum aestivum L.) in the Northern parts of Iran. Although, several measures such as crop rotation and crop protection (via chemical and biological control) have been used to control Hill, the development of FHB resistant varieties is supposed to be the most economic and effective way of control. For estimation of genetic parameters of Fusarium resistance, eight wheat cultivars with different levels of resistance to FHB, were crossed in a DIALLELE fashion with no reciprocals. The F1s, and parental lines were evaluated under artificial inoculation during 2001 and 2002. Disease development was assessed by area under the disease progress curve (AUDPC). The result of genetic analysis employing Haymans method revealed that additive - dominance model was adequate to explain the genetic variation for AUDPC. Variation for AUDPC was mostly determined by additive and dominance components of genetic variance.

Seedless grapes are widely grown all over the world. Embryo rescue technique proved to be able to overcome the problem of embryo abortion in seedless grape breeding program. Since, the efficiency of this technique is not desirable, so a lot of efforts have been done in different directions in order to improve this technique. This study was conducted in two separate experiments in which chlormequat and putrescine were employed in different experiments. Cultivars of Yaghooti, Flame Seedless and Perlette were used as both female and male parents in both experiments. Clusters sprayed with different concentrations of chlormequat and putrescine 14 days before blooming. Ovules were excised from berries 45 days after pollination and cultured in NN medium supplemented with 3.0% sucrose, 0.2% activated charcoal and 6% agar. Embryos were removed from the ovules after 10 weeks and transferred onto MS medium supplemented with 2.0% sucrose, 0.2% activated charcoal and 6.5% agar. The results showed maternal and paternal genotypes, pre-treatment with chlormequat and putrescine had positive and significant effect on endosperm and embryos development, embryos germination and plant production. The use of cv. Perlette as female parent, cv. Yaghooti as male parent and pre-treatment with chlormequat and putrescine at 100 and 30 mg/L increased the percentage of measured traits.

A diallel cross analysis was used to estimate general and specific combining ability of resistance to cercospora leaf spot in six lines of sugar beet. The parents and 15 hybrids (F1) were evaluated in a randomized complete block design with four replications at Safiabad Agricultural Research Center. A mixture of cercospora agent was grown in the laboratory in V8A media. The infection was created in "Khusestan", in 2001 by three times sprays. Genetic parameters were estimated by Griffing, Jinks and Hyman methods. The results showed that both additive and non-additive genetic effects contributed to the expression of this trait, but the portion of additive and heritable effects of genes are more important. Therefore, there is a relative dominance in genetic control of leaf spot infection. Broad sense and narrow sense heritability were 99% and 79%, respectively. Because of a high amount of additive gene effects and rather high narrow sense heritability, the selection efficiency would be successful in cercocpora leaf spot resistance. The results also indicated that the resistance to this infection could be controlled by recessive genes. Parents 7617 and 261 with less infection intensities have general combining abilities in resistance, so they are suitable parents for resistance increase and can be used in breeding program.

A complete DIALLELE crosses derived from eight oilseed rape (Brassica napus L.) genotypes was used to estimate the genetic parameters for seed yield, 2-propenyl (allyl), 3-butenyl, total glucosinolate, oil and protein contents. Analysis of variance based on Griffing's Method one with Mixed- B Model revealed the presence of significant mean squares for general and specific combining abilities and reciprocal effects, indicating additive, non-additive and maternal effects, contributed to genetic control of the studied characters. High narrow-sense heritability estimates for the three types of glucosinolates indicated the prime importance of additive genetic effects. However, the degree of dominance greater than one for seed yield, oil and protein contents showed the importance of non-additive genetic effects for these traits. Significant heterosis over better parent was detected for allyl, 3-butenyl and total glucosinolate contents, seed yield, oil and protein percentages. Non-significant correlation between studied traits and seed yield suggested the possibility of improving these traits without any considerable changes in the seed yield. In general, PF7045/9 I and BL I (breeding lines) were good combiner parental lines for seed yield and low glucosinolates. The crosses PF7045/91 x Shiralee and BL1 x PF7045/9 I had the highest positive and negative heterosis for seed yield and glucosinolates, respectively.

Response of five cultivars (with different levels of resistance to sunnpest) and their F1 progenies, produced through half - DIALLELE crossing, were evaluated under field conditions, using a randomized complete block design of three replications. The experiment was carried out in Agricultural College, of Razi University in 1997. Analysis of variance revealed significant differences among genotypes regarding percentage of increase in weight of mother sunnpest, decrease in biological yield, seed, yield and seed number in spike. DIALLELE analysis using Griffing (method II) and Hayman procedures were performed. Combining ability analysis indicated significant differences in percent increase in weight of mother sunnpest for both general and specific combining ability effects. Regarding the above mentioned traits, Rashid (with the lowest GCA effect), Navic Sardari (with the lowest SCA) were the most suitable varieties and hybrids for higher resistance. Non-additive gene effects for the increase in weight of mother sunnpest were of over dominance natures while for the other traits, of partial dominance. There is the highest number of dominant genes for the increase in weight of mother sunnpest present in Sabalan cultivar whereas the highest number of recessive genes is observed in Sardari cultivar. Broad and narrow sense heritabilities for the increase in weight of mother sunnpest were 74.58 and 25.25 percent, respectively. No significant correlation between grain damage and morphological characters was observed. Correlation observed between grain damage and protein quality was negative and significant.

The aim of this study was to partial genome scan (chromosome 5) of Japanese quail to detect QTLs affecting growth traits based on a four-generation partial DIALLELE cross design in Special Domestic Animals Research Center of University of Zabol. For this purpose, four strains of Wild (A), A and M of Texas (B), Italian Speckled (C) and Tuxedo (D) Japanese quails were crossed in two-strain reciprocal method and were created the first generation. Grandparents and fourth parents (18 and 36 birds, respectively) and all birds of fourth generation (315 birds) were genotyped for three microsatellite markers on chromosome 5. Also, all birds from hatch to 45 days were weighted at 5-day intervals. The QTL analysis was carried out using a regression-based interval mapping method and additive genetic model using GridQTL software. The results showed three different QTLs for hatch weight, weights at 15 and 20 days of age in 4. 65, 16. 03 and 15. 63 cM, respectively. Therefore, if the adjacent marker information be entered in equation of breeding values estimation, it can lead to improve the reliability of prediction breeding value and finally result in genetic progress.

The majority of breeding programs of edible mushrooms are carried out in the button mushroom due to its commercial importance and genetic difficulties. In this research, for the first time in Iran, it was possible to examine intra-hybridization and its effect on both productivity and mycelium morphology as a potential for commercialization. The strains comprised six heterokaryons and four homokaryons from different sources. Twenty five homokaryotic isolates were obtained from six heterokaryon and having 29 homokaryons, 406 DIALLELE crosses were performed from which 145 crosses were compatible. Productivity of compatible crosses was examined in an industrial mushroom farm on a basis of randomized complete block design with two replications. From 145 crosses, nine hybrids which had significantly higher yield than the control, were used in yield trials performed in two industrial mushroom farms on a completely randomized design basis with three replications. The yield of three hybrids was significantly higher than the control. For these hybrids, a strain registration form was prepared. The resulting information showed some interesting points, particularly about the study of pedigree of offspring having high performance than the control, which will be useful in designing the future breeding programs.