جستجوی مقالات مرتبط با کلیدواژه « ترکیب پذیری خصوصی و ترکیب پذیری عمومی » در نشریات گروه « زراعت »

Low diversity and poor genetic basis of germplasm in temperate regions is a significant challenge in maize breeding. Maize germplasms from tropical and subtropical regions often contain a broader genetic base and show larger diversity than germplasms from temperate regions. Therefore, it seems that foreign germplasms, especially germplasms from tropical and subtropical regions, can be used as a potential solution to strengthen the genetic base of germplasm in temperate regions. However, the efficiency of screening methods to identify superior and suitable sources of foreign germplasm remains a major challenge. The objective of this study was to determine the optimum number of testers and select suitable testers for screening maize lines derived from tropical and subtropical CIMMYT germplasm.

In this experiment, three testers of temperate regions (MO17, B73, K1264/5-1) were crossed with 25 lines originated from the CIMMYT maize germplasm based on line × tester mating system. A total of 75 crosses along with the control hybrid (SC704) were evaluated in alpha-lattice experimental design in two replications each with four incomplete blocks in two regions (Moghan and Jiroft). Analysis of variance was done based on line × tester method, as well as separation of the effect of crosses into its components using the method suggested by Kemptorn (1957). GGE-biplot graphical analysis based on the methodology proposed by Fan et al. (2010) was also used to estimate the effects of general combining ability (GCA) and specific combining ability (SCA).

The results showed that out of the 75 crosses, 32 crosses had higher and significant grain yield compared to the control hybrid SC704. The superiority of the superior cross compared to the control hybrid ranged from 1.46 to 3.77 tons per hectare. These findings highlighted the potential of utilizing tropical and subtropical CIMMYT germplasm to enhance maize yield in temperate regions of Iran. Based on the results, the lines No. 22, 9, 19, 12, 20, 5, 17, 21, 24, 14, 15, 23, and 11 had the highest positive GCA for grain yield, respectively. In general, in terms of grain yield, GCA, and SCA, it is possible to directly use lines No. 4, 5, 9, 11, 12, 19, 22, and 24 extracted from tropical and subtropical CIMMYT germplasm to improve grain yield in temperate regions. Evaluating the efficiency of the temperate maize testers also showed that two testers B73 and MO17 were highly efficient in selecting superior line derived from tropical and subtropical CIMMYT germplasm.

The results of the current study showed that it is possible to use maize germplasms from tropical and subtropical regions of CYMMIT to improve grain yield in temperate regions. Also, one temperate maize tester has the ability to distinguish superior sources (not all of them), although the use of two testers greatly reduces the risk of not choosing (deleion) a superior source.

Increasing rice production is one of the demands of the world market and one of the goals of many countries that produce this staple crop. Development of high yielding cultivars is one approach and perhaps the only one to supply the country's rice demand. Knowledge of the genetic parameters that control different traits, including heritability, the average degree of dominance, and gene action is very important in choosing a breeding scheme that lwads to development of improved high yielding cultivars. The diallel designs proposed by Griffing, Jinks, and Hayman provide information about the genetic suitability of parents to be used in breeding programs. This experiment was carried out to estimate the combining ability and the type of gene action of eight Central and Western Asian rice varieties using diallel crossing design.

In this experiment, eight rice varieties from Central and West Asia were used as the parents of the crosses. The progenies obtained from the diallel crossing design along with their parents were grown using randomized complete block design with three replications in the experimental field of Rice Research Institute of Iran, Rasht, Iran. During the growth duration, according to the standard evaluation method of the International Rice Research Institute (IRRI), the necessary evaluations for agro-morphological characteristics were carried out. Diallele analysis was performed using the second Griffing method under the first model (with fixed effect). Baker's ratio was used to determine the contribution of additive variance in the genetic control of studied traits. Also, diallel analysis proposed by Morley Jones method done to estimate gene actions and genetic variance components (additive and dominant). SAS 9.4 and DIAL98 softwares were used to perform preliminary variance and diallel analysis.

The results of diallel analysis by Griffing method to estimate combining ability showed that general and specific combining ability were significant for all studied traits which indicated the importance of additive and non-additive effects in the genetic control of these traits. Baker's ratio for grain yield, number of fertile tiller number per plant and number of filled grains per panicle showed that non-additive gene effects had a significant contribution in the genetic control of these traits. The value of Baker's ratio in plant height, panicle length and number of days to 50% of flowering indicated the presence of additive and non-additive gene effects in the genetic control of the aforementioned traits. Evaluation of general combining ability showed that the highest combining ability was observed in D3, Ghadeer, Atai-1 and Hashemi cultivars for grain yield, fertile tiller number per plant, filled grains per panicle and panicle length, respectively. Also, D3 and Marjan cultivars had the lowest general combining ability for plant height and days to 50% of flowering. The estimation of specific combining ability showed that for grain yield, Atai-1×Marjan cross, for fertile tiller number per plant, Ghadeer×Atai-1 cross, for filled grains per panicle, Marjan×Atai-1 cross and for panicle length, Ghadeer×Marjan cross had the highest specific combining ability. The estimation of genetic parameters of diallel genetic analysis showed that the contribution of non-additive gene effect in the genetic control of grain yield, fertile tillers per plant, plant height, filled gains pe panicle and panicle length was higher than additive gene effect.

considering the resuts of this experiment, it can besuggested that D3 cultivar is suitable parent for increasing grain yield as well as reducing plant height, and Marjan cultivar is suitable parent for shortening growth duration, in targeted crosses. The results also showed that Atai-1×Marjan cross had the highest specific combining ability for grain yield. Therefore, this combination is suggested for the development of high yield potential hybrid rice cultivars. The best combination for shorter plant height was Jalal×Atai-1 cross. The estimation of genetic parameters of diallel analysis showed that designing breeding schemesfor development of hybrid rice cultivars to improve grain yield and reduce plant height will be promising. The results also indicated that the use of selection method to reduce the length of growth duration will be possible.

In order to estimate genetical parameters, general and specific combining ability of bread wheat to determine proper parents for crossing and producing new cultivars, six promised lines planted in randomized complete block design with three replications, in 2017-18 cropping and varieties including, Falat, Mehergan, Ehsan, Sistan, Bam and N-80-19 were planted in Eraghi Mohalle (Gorgan) station in 2016-17 cropping season. A full diallel mating among six parents for generating F1 progenies were done. Sixparental genotypes and 30 F1 progenies were season. The results revealed that cultivar Ehsan was the best general combiner for hundred grain weight. Cultivar Ehsan and Line N-80-19 had the highest general combining ability for grain yield and biomass, respectively. Therefore, it is recommended that these genotypes can be applied in hybridization to increase grain yield and biomass. Additive variance of traits including plant height, peduncle length, grain weight in spike and hundred grain weight was more than dominance variance. Furthermore, Ehsan cultivar had the highest general combining ability (GCA) for grain yield and biomass and hybrids raised from 2×3 (Ehsan×Mehrgan) cross had the highest specific combining ability (SCA) for grain yield and biomass.

Wheat is attacked by many pathogens during the growing season, including rust. The causative agent of fungal wheat brown rust called Puccinia recondita f. sp. is also known as leaf rust. The most important way to control brown rust disease is to use resistant cultivars that effectively control and reduce its damage. The most important way to control brown rust disease is to use resistant cultivars that effectively control and reduce its damage. The aim of this study was to investigate the inheritance of brown rust resistance in different wheat cultivars and estimation of genetic parameters using diallel crossing.

Six bread wheat cultivars including Gonbad, Shiroudi, Darya, Atrak and Moghan 3 genotypes with susceptible Bolani cultivar and 15 F1 progenies from one-way diallel crosses were studied. his study was conducted as a randomized complete block design with three replications in field and greenhouse conditions. Traits included infection type, severity of infection, area under disease progression curve and incubation period. Data analysis was performed using SAS ver 9.1 and Excel software and estimation of genetic parameters and heritability of traits were studied by diallel analysis using Griffing's second method with fixed model and Jinks and Hayman method.

Analysis of variance showed that there was a significant difference among genotypes for all traits, indicating genetic variation for these traits and thus genetic analysis could be performed. The mean squares of general and private combining ability were significant for all traits, indicating the importance of both enhancing effects and dominance of genes in inheriting these traits. The Baker ratio indicated the same importance of additive effects and dominance for the incubation period and for the other traits indicated greater importance of additive effects. Estimation of genetic parameters by Jinks and Hayman method showed that for all four traits, the amount of D component was lower than the dominance components (H1 and H2), indicating that the dominance component was more important than the additive component in controlling these traits. The sign of F was positive for all traits, so the frequency of dominant alleles was higher than that of recessive alleles. Wr-vr statistic was significant for all studied traits, indicating the presence of inorganic effects (epistasis). In other words, the significance of this statistic indicates the inaccuracy of the additive-dominance model for traits.

Based on the traits evaluated in field, Atrak cultivar and in greenhouse, Gonbad cultivar had good resistance to brown rust. Narrow-sense heritability of traits was estimated to be between 51 and 86%. Estimation of genetic parameters showed that additive-dominance model was not sufficient. In other words, at least resistance is predictable in resistant cultivars.

Five CMS lines and four restorer lines (tester) were crossed in a line × tester scheme in order to analyze general and specific combining abilities and gene effects in sunflower for some agronomic traits. Hybrids were evaluated in a randomized complete block design, with three replications under optimum and limited water conditions in the Agriculture Research Station, Khoy, during 2015 and 2016 growing seasons. Plant height, head diameter, seeds per head, days to beginning of flowering, days to maturity, proline percent, protein percent, and Chlorophyll b were found to be controlled mainly by dominance effects. CMS lines AGK30 and testers RGHK25 and RGHK50 turned out to be the best general combiners for seed and oil yield. The highest positive and significant GCA for plant height, head diameter, and the number of seeds per head were achieved for RGHK25. The hybrid combination of AGK44 × RGHK56 showed high specific combining ability for seed and oil yield. In the study of general combining ability, the AGK110 line has a positive and consistent general combining ability, and AGK2 has a negative and significant general combining ability with catalase . In the test of the testers, the tester (RGHK50) had the highest GCA positive and meaningful drug tester (RGHK56), which had a significant negative and significant combining ability with catalase . In the study of hybrid hybrid combining ability (RGHK46 × AGK260), the highest positive and significant positive and significant hybrid confinement (RGHK46 × AGK44) had the highest SCA negative and significant levels. In the RGHK46 × AGK260 hybrid combinability study, the highest positive and significant positive and significant hybrid confinement (RGHK46 × AGK44) had the highest SCA negative and significant effect on catalase identity. The AGK44 line has the ability to combine publicly and positively with AGK110 capability. The general combining ability was negative and significant with SOD. In the test of the testers, the RGHK 56 tester had the highest GCA positive and significant mean of the RGHK25 tester, which had a negative and significant general combining ability with superoxide dismutase. In the study of hybrid hybrid combining ability (RGHK50 × AGK260), the highest positive and significant positive and significant positive combining ability (RGHK50 × AGK44) had the highest SCA negative and significant values for SOD. In explaining the traits, plant height, Number of seeds per head and percentage of proline under stress conditions played a more significant role. Plant height and number of seeds per head were controlled by both growth and dominance effects. also In the study of general combining ability, the highest GCA positive and significant values were related to the AGK30 line and the most general negative and significant general combining ability was AGK2 line (Table 4-14). In the test of the testers, the tester (RGHK 46) had the highest GCA positive The drug tester (RGHK25) had the most significant negative and significant general combining ability with proline). In the study of hybrid combining ability (RGHK46 × AGK2), the highest positive and significant positive and significant hybrid confinement (RGHK25 × AGK260) had the highest SCA negative and significant values .

Six rainfed durum wheat genotypes (Chehel daneh, Gerdish, Zardak, Syrian-1, Waha and Knd1149//68/ward) and their complete diallel progenies of F1 generation were evaluted in a randomized complete block design with two replications. Analysis of variance indicated genetic differences among genotypes. General combining ability (GCA) was significant for all of the studied traits except hundred grain weight (HGW). Specific combining ability (SCA), reciprocal and non-maternal effects were significant for grain yield (GY), HGW and flag leaf area (FLA). The results indicated low values of narrowsense heritability and superiority of dominance effect for plant height (PH), GS, GY, HKW and FLA. The cross of Waha × Knd1149//68/ward with high value of GY and GCA for this trait can be used as a suitable cross for use of heterosis. This cross was also superior to their parents according HGW, NGS and SL. Gerdish can be used as a suitable parent for breeding programs to receive lines with high yield and yield components according to positive and significant GCA for number of spikelets per spike, SL, NGS, GY and FLA. According to predominance of additive effects in genetic control of number of spikelets per spike and spike length, selection can be useful for improvement of these traits, while selection was not applicable in primary generations and should be delayed for the other traits untill advanced generations.

IntroductionDiallel crosses can be used to study the gene action and heterotic grouping and patterns. In the recent decade, use of graphical approach or GGE biplot in the investigation of genotype × environment has become more common in breeding programs. In this method, the effect of genotype and genotype and environment interaction are broken and stable cultivar selection is done basis of both effects. When GGE biplot was used for diallel data, each genotype reviled as both line and tester. Also in this case, average performance and stability of genotypes equivalent with the parent GCA and SCA respectively. Biplot method very useful tool for visual assessment and interpretation of the parent’s pattern, the environment and their interaction. The aim of this study provides the following information for wheat base graphical (1) Set parental general combining ability, (2) Estimates specific combining ability for hybrids, (3) Determine the adequate testers for future research, (4) Determine the best hybrids, (5) Determine of heterotic group and patterns among genotypes.
Materials and MethodsIn this study, seven varieties of wheat including Alamut, C-84-12, Gaspard, Ghods, Moghan 1 and Afshar (as parents) were used. These varieties with 21 genotypes of F1 generation of them base half diallel (without reciprocal crosses) in 2012-2013 crop year on research farm of Agriculture and Natural Resources, Islamic Azad University of Karaj, in drought stress condition were cultivated. A randomized complete block design with three replications was used. To analysis of variance SAS software and for Diallel analysis D2 software were used. Graphical analysis according to Yan and Hunt method done with GGE biplot software. In order to evaluate the diallel results in bread wheat, biplot method was used. In this study, 12 agronomic traits, including Grain yield, Plant height, Spike length, Spike Weight, Stem diameter length, Awn length of the second internodes, Peduncle length, Extrusion peduncle, Seed length, Seed size and 1000 Seedweight were examined.
Results and discussionAnalysis of variance showed significant differences for most of the traits. General combining ability mean squares for all the traits except plant height, length of the second internodes and stem diameter was significant. Specific combining ability mean squares for all traits except stem diameter was significant at the one percent probability level. The highest and lowest average grain yield for parents was observed for Hamoon and Afshar cultivars and for hybrids observed for crosses the Hamoon × Ghods and C-84-12 × Gaspard. The most significant positive GCA for grain yield, was reviled for Hamoon variety. The most significant SCA for grain yield per square meter, observed for Hamoon × Ghods and C-84-12 × Moghan1. For spike weight, the highest and significant SCA values observed for Afshar × C-84-12 and Alamut × Gaspard. For grain weight the highest SCA observed for Alamoot × Ghods and Afshar × C-84-12. For spike length, Alamoot × C-84-12, Ghods × C-84-12, Afshar × Gaspard and Ghods × Moghan1 had a positive and significant SCA. Based on the results of diallel analysis biplot for grain yield of the lines, Cultivars Alamut and Afshar respectively, have a highest and lowest general combining abillity. Cultivars C-84-12, Ghods, and Gaspard has a specific combining ability were higher than other lines. Cultivars were divided into two groups. The first group includes Cultivars Gaspard, C-84-12 and Hamun, second group includes Alamut, Ghods, Moghan1 and Afshar. Testers Ghods, Alamut, C-84-12 and Gaspard similarities and relationships more than other tester for grain yield. Cultivars Ghods, C-84-12 and Alamut had more discriminating effect than other varieties.
ConclusionsIn total, there were significant genetics diversity between cultivars that cause of the additive and non-additive effects in the studied traits such as yield. Comparing the results of numerical analyzes with graphical results represents the good conformity between of these two methods. Due to preferable of graphical methods in terms of faster and simpler interpretation for results, the use of these methods, to facilitate the investigation, recommended.

GGE biplot method is one of the appropriate methods for analyzing the data with bilateral structure. In the present research, the GGE biplot model was used to identify promising heterotic crosses for paste viscosity parameters in rice (Oryza sativa L.) by using 8×8 full diallel progenies. In direct crosses, parents Deylamani, RI1843046, IR50 and RI184421 were identified as good general combiners for peak viscosity, while in reciprocal crosses, only parent RI184421 was the best combiner for this trait. The parents RI1843046 and RI184421 for breakdown viscosity property and the parents BC4, Deylamani and Tarommahalli for final viscosity parameter were identified as good general combiners in direct crosses, but RI1843046 was the best general combiner for both trait in reciprocal crosses. Although, the parents BC4 and RI184421 were respectively the best general combiners for setback viscosity in direct and reciprocal crosses, but the parent Deylamani was good general combiner for this trait in progenies of both cross. The results of this research showed that the crosses RI1843046 × RI184472, RI184472 × Deylamani and Deylamani × IR50 for peak viscosity, RI1843046 × Line 23, RI184472 × Deylamani and RI184472 × Tarommohali for breakdown viscosity, RI1843046 × RI184472 and RI184421 × IR50 for final viscosity and BC4 × RI1843046 and Deylamani × Line 23 for setback viscosity were the best specific combiners. The good general combiners to organize a new population and the good specific combiners as the suitable heterotic combinations for producing the progenies with suitable paste viscosity properties are suggested.

To estimate combining ability and the model of gene action for some quantitative characters, 5 different rice genotypes were used for producing a half diallel hybrids. To consider 7 quantitative traits, hybrids and their corresponding parents were evaluated based on a randomized complete block design with three replications at the Rice Research Station of Amol, Iran in 2007. Mean squares regarding genotypes were statistically significant at 1% level of probability for all the studied traits. Significant general and specific combining abilities for all traits implied that additive and non-additive effects were effective in controlling these traits. Also, a non significant ratio for all characters except for 1000 grain weight expressed the greater importance of non-additive genetic effects rather than the additive ones for controlling the studied traits. Overall, parents Dasht, Neda and Binam were superior in general combining ability and hybrids Mashad Domsiah×Binam and Binam×IR6287-1-10 were the best for specific combining ability regarding yield and its components.

Study of the action of genes involved in controlling grain yield, plant height, ear height, ear length, ear diameter, grain/ear row, row no./ear, grain no./ear, 100 grain weight, cob percent, grain weight/ear, in maize, a diallel cross with 14 inbred lines was carried out. Parents and their F1's were tested using randomized complete block (RCB) design with three replications in Research station of Seed and Plant Improvement Institute, Karaj in 2006 cropping season. Significant (p<0.01) differences were observed among genotypes for all traits, therefore Griffing’s method 2, model 1 was used for subsequent diallel analysis. Variances due to general combining ability (GCA) and specific combining ability (SCA) were significant (P < 0.01), for all traits. Results indicated that for ear diameter, number of grain row per ear, 100 grain weight and additive gene effects were more important than non additive gene effects, but for grain yield, plant height, ear height, number of grain per row and number of grain per ear, non-additive gene effects were more important. For ear length, cob percent and grain weight per ear, both additive and non additive gene effects were important. High broad sense heritability observed for all traits (>60%), the estimate of narrow sense heritability for yield was 25%, high value belonged to the number of grain row per ear (71%) and low value obtained for ear height (18%). Parents with high GCA for grain yield were K19/1, K166B and K3615/2 inbred lines. For other traits, GCA effect was significant in about 50% of the inbred lines. SCA effect was significant in few crosses for all the traits. The highest heterosis for grain yield was observed in A679 × K3493/1 cross.