Recognition and understanding the genetic control of traits, combining ability and genetic structure are directly related to the success of breeding programs. For this purpose, a 7 × 7 one-way diallel design was conducted in a randomized complete block design with three replications. The measured traits were included plant height, height to the first capsule, number of days to 50% and 90% of flowering, number of capsules per plant, number of seeds per capsule, number of days to physiological ripening, number of branches, leaves number and length, 1000-seeds weight, capsule weight, length and width, chlorophyll a, b and total chlorophyll, biological andeconomic yields, harvest index, oil and protein percentage. Analysis of variance showed that there was a significant difference between genotypes and diallel analysis showed that the additive variance of all traits and dominant variance of all traits except height to the first fruit-bearing capsule were significant. The oltan cultivar was the best and Ardestan genotype was the worst genotype in terms of general combining ability. Sabzevar×TS-3 and Sirjan×Fars were the best hybrids in most traits. The general heritability was between 0.90 to 0.96 for biologic yield and number of branches, respectively and narrow heritability was between 0.36 to 0.91 for the number of branches and harvest index, respectively. The analysis of variance by Hayman method confirmed the results of Griffing analysis.

To achieve favorable outcomes in breeding programs, selection of parents based on General Combining Ability (GCA) and Specific Combining Ability (SCA) is so important. In order to study the genetic parameters, general and specific combining abilities and the type of disease resistance genes action against take-all disease in bread wheat, 6 wheat genotypes (729, 1622, 2109, 1528, 1546 and 1526) were crossed in one-way diallel cross. Seeds of F1 generations (F1s) and parents were planted in the research greenhouse of Vali-e-Asr University of Rafsanjan, Iran and take-all disease tolerance, stem and root dry weights, tiller number and elements such as manganese (Mn), zink (Zn), potassium (K) and iron (Fe) concentrations in plant tissue were measured. The results of Griffing analysis showed that general and specific combining abilities were significant for all traits except tiller number and K element. In terms of Take-all disease resistance, the best general combiners were 1622 and 729 genotypes, respectively. The best resistant hybrids were 2109×1546, 546×1528 and 1622×1526 that had the highest specific combining ability. Evaluation of genetic parameters by Hayman method for disease index and disease score confirmed the results of Griffing analysis and showed that the dominance and over dominance of gene actions had the greatest importance in genetic control of the resistance to take-all disease (T-41 isolation). Finally, due to low narrow sense heritability and low genetic ratio in resistance to take-all disease, it can be concluded that selection for resistance to take-all disease does not respond well in early generations, so selection after purity, that done by bulk, single-seed descent and double haploid methods can be effective in wheat breeding.

Six Iranian rice cultivars (Binam, Domsiyah, Shahpasand, Sepidrud, Khazar and Valed 46) were crossed in 1989 in the Iranian Rice Research Institute in Rasht, Iran in a full-diallel design. The F1 progenies together with parents were transplanted in a CRBD in the 5 x 0.75 m plots at plant density of 25 x 25 cm (60 plantlets per plot) in 3 replications. Part of this research was published in 1994 as a half-diallel design and the data of full-diallel, using Griffing approach, is subject of this paper. The analysis of variance showed significant differences among genotypes. The mean of six parents, 15 crosses and 15 reciprocal crosses were analyzed using the four diallel crossing systems of the Griffing approach. The SS of genotypes were separated into GCA for each parent and SCA for each cross using corresponding formula. The additive variance (VA) and dominance variance (VD) values were estimated using the table of variance analysis. The heritability (h2ns) was also estimated from VA and VD variances. The simple variance analysis of “grain yield per plant” and other agronomic traits using each of the 4 diallel crossing methods of Griffing showed significant differences (P < 1%) among genotypes, indicating a sufficient genetic potential of the investigated genotypes. The GCA variance analysis of the lines was significant for all the characteristics, indicating the importance of additive variance (VA) by inheritance of these traits. Using Griffing’s diallel methods 1 and 3, SCA variances for all investigated traits showed significance, whereas in the methods 2 and 4, traits “1000 grain weight” and “tiller per plant” were not significant according to SCA. This also indicates the importance of dominant variance (VD) in most of the traits, except for “1000 grain weight” and “tiller per plant”. The differences among the reciprocal crosses in diallel methods 1 and 3 were also examined; where for all the characteristics (except for “deaf grains per panicle” and “length to breadth ratio of brown rice grain”) significant differences were observed, suggesting the possibility of cytoplasmic effect of mother line on the reciprocal crosses. The heritability (h2ns), which indicates the ratio of additive variance (VA) to phenotypic variance (VP), was estimated to be equal to zero due to the absence of additive variance for grain per panicle and the number of days from transplanting to full maturity of grain. The heritability for other characteristics was estimated high or low according to additive variance. For example in all 4 diallel methods the heritability estimation for length to breadth ratio of brown rice grain was relatively high (65 – 71%) whereas for “panicle length” and “grain yield per plant” was relatively low (13 – 48%). The correlation among genetic parameters (VA, VD, D, h2ns) were generally high and significant.

Estimation of genetic diversity, combining ability and heterosis of maize inbred lines for breeding aims are very important and would determine breeding strategies. In order to potential genetic estimation of Iranian corn inbred lines using diallel and AMMI methods, fourteen corn inbred lines cross according diallel scheme. Parents and their hybrids were evaluated in 2007 at Seed and Plant Improvement Institute, Karaj, using Randomized Complete Block design with three replications. Results indicated that Significant (p<0.01) differences were observed among the genotypes for all the studied traits, therefore Griffing’s method 2, model 1 was chosen for subsequent diallel analysis. Variances due to GCA and SCA were significant for all the studied traits (P<0.01). Results indicated that for number of kernel row per ear, 100 seed weight, cob percent and kernel moisture percent additive gene effects were more important than the non additive ones, but for grain yield, plant height, ear height, ear diameter, number of kernel per row and number of kernel per ear non additive gene effects were more important than the additive ones. For ear length and kernel weight per ear, importance of additive and non additive gene effects was the same. The best AMMI model for yield was AMMI3 explained 75.6% of interaction variance. The best general combinatory for yield were lines K166B, K3615/2 and K3653. The highest specific combining ability and mid-parent heterosis for yield according Griffing, first and second AMMI components was observed in MO17 × K3653, K166B × K3653, K166B × K3653, A679 × K3544/1 and K3653 × K3493/1.

Objective: Developing new and adaptable cultivars suited to different environments is a primary goal for breeders. This study aimed to evaluate the genetic characteristics, including general and specific combining abilities, using a half diallel cross among nine bread wheat cultivars. Method: Seeds of 36 F₁ hybrids derived from nine parents were planted in a randomized complete block design with three replications under normal and drought stress conditions. The parents and hybrids were evaluated based on morphological and agronomic traits such as plant height, days to maturity, spike length, peduncle length, thousand-seed weight, flag leaf area, and grain yield. Combining abilities and gene action were estimated using Griffing’s method 2 (B model) and analysis of variance following Jinks and Hayman's approach. Results: Analysis with Griffing’s method 2 and Hayman-Jinks revealed significant effects of both general combining ability (GCA) and specific combining ability (SCA) across all traits and conditions, indicating the presence of both additive and non-additive genetic components. Parents Roshan, Shahpasand, and Azar2 exhibited high GCA for most traits under both conditions. Hayman’s variance analysis showed significant additive (a) and dominance (b) components for all traits in both environments. The significance of the b₂ component suggested an unequal distribution of dominant and recessive alleles. The b₃ component, indicative of SCA, was significant across traits. Heritability estimates ranged from 55% to 74% (broad-sense) and 14% to 61% (narrow-sense) in both conditions. Conclusions: Traits such as plant height, spike length, peduncle length, and days to maturity under normal conditions, as well as spike length, peduncle length, thousand-seed weight, and flag leaf area under drought stress, can be effectively selected in early generations. For traits like seed weight, flag leaf area (normal conditions), plant height, days to maturity (drought stress), and grain yield in both conditions, selection should be delayed until advanced generations when traits are genetically fixed. Breeding methods such as pedigree, backcrossing, bulk, single seed descent, and doubled haploid techniques are recommended to accelerate genetic fixation.

Five wheat varieties were used to estimate gene action for morphological traits and yield and estimate the heritability of traits. The varieties including White Bolani, Brown Bolani, Tajan, Kealk and AS48 mutant have been crossed based on full diallel. The F2 genotypes were planted in a randomized complete block design with three replications in the Nuclear Agricultural Research Institute. Analysis of variance for all the traits revealed that the general combining ability was significant so these traits were controlled by additive genetic effects. The heritability of traits were high and therefore selection based on these will be successful. Additivedominance model was sufficient for this research and non-allelic effect weren’ t observed, therefore Hayman analysis was performed. Hayman’ s analysis of variance showed that the additive effects and non-additive effects control the traits. For number of spikelet per spike, second and third internodes diameter, second and third internodes length and leaf area traits, the average degree of dominance indicate that partial dominance controls these traits. Heyman’ s graphical analysis showed that partial dominance was involved in controlling these traits.

The theory and analysis of diallel crosses have been defined and developed by many scientists. Griffing in 1965 described the diallel analysis in four methods with four models. In this study estimation of genetic parameters through different methods of Griffing approach was compared. Seven lines of Brassica napus L. were crossed in all possible combinations including reciprocal crosses. Forty two F1s together with seven parents were planted using randomized complete block design with 2 replications. Combining ability analysis was carried out for 12 agronomic characters on the basis of four methods of Griffings approach. Estimation of additive (σA2) and dominance (σD2) genetic variances and calculation of dominance ratio (σD2/σA2) was carried out for these methods. The estimation of additive and dominance genetic variances in the method 3 were negative for all characters and in method 2 and 4 they were negative only for some characters. However, in method 1 additive genetic variance was positive for all characters. Considering the estimation formula for additive and dominance genetic variances it was concluded that, when mean square specific combining ability (SCA) is greater than mean square of general combining ability (GCA), estimation of additive genetic variance is negative. This situation was observed in methods 2, 3, and 4 but not in method 1. It was indicated that components of genetic variances was better estimated in method 1 than the other methods in this study. Results indicated that the method 1 provided consistent estimation of additive and dominance genetic variance and was superior in comparison with the other Griffing methods.

In this study, a comprehensive meta-analysis was conducted using a random-effects model to examine the relationship between money supply and inflation and to address inconsistencies in previous research. The overall effect of money supply on inflation was estimated at 0/578, providing a broad measure of its impact. However, an assessment using a funnel plot and Egger's test revealed publication bias. To correct for this bias, the "trim and fill" method was applied, reducing the adjusted overall effect to 0/475. Additionally, meta-regression and subgroup analyses were performed to investigate moderating variables. The results showed that the effect of money supply on inflation differs across fixed and floating exchange rate regimes, time periods before and after 2000, and between static and dynamic models. These findings contribute to a clearer understanding of the impact of monetary and economic policies on inflation and provide a foundation for future research.

The production of new and compatible cultivars to different environments is one of the most important goals for the breeders. The crossing new cultivars and the selection of superior genotypes for desirable traits among their offspring is a method that has always been used by breeders. 28 genotypes obtained from the crossing of a 7 × 7 one-way diallel experiment consisting of seven parents (Alvand, Anfarm9, Chamran2, BC Roshan, Qods, Ofogh, local variety Sorkh-dane) and their 21 hybrids were investigated in a randomized complete block design with three replications in the research field of the Faculty of Agriculture of University of Birjand (Iran) under non-stress and drought stress conditions. The analysis of variance showed a significant difference among genotypes for all traits. Mean squares of GCA and SCA were significant for all traits under non-stress and stress conditions, so, there were additive and non-additive components of heritable variance in all traits. The BC Roshan parent had the high combining ability and Ofogh parent had the lowest combining ability in most traits in non-stress and stress conditions. In both conditions, BC-Roshan × Chamran2, Sorkh-dane × Qods and Ofogh × Anfarm9 hybrids had the highest yield and yield dependent traits. Hayman's variance analysis showed that component a (additive genetic diversity), component b (dominance genetic diversity), component b1 (heterosis), component b2 (heterosis specifically for each parent), and component b3 (specific dominance deviation per cross) were significant in both conditions in all traits. The Hayman's analysis confirmed the results of Griffing's analysis.