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

 Wheat is one of the most important and strategic plants that is important because of nutritional value. The knowledge of genetic control and inheritance of yield components is essential to selecting the best breeding method. Therefore, comprehensive and accurate information about the genetic parameters controlling yield components should be considered in deciding to select the appropriate breeding method to maximum grain yield.

 The seven genotypes, including Alvand, Anfaram9, Chamran2, Back Cross-Roshan, Ofogh, goods and local variety Sorkh-Dane and 21 hybrids from them was studied in a 7 × 7 one-way Diallel designs during 2015-2016.

 Analysis of variance showed that there was a significant difference between genotypes. Griffing's diallel analysis showed that the general and specific combining ability was significant in all traits. The best genotypes were BC-Roshan and Sorkh-Dane and the worst genotypes were Ofogh and Ghods because of general combing ability. BC-Roshan × Chamran2 and Alvand × Ghods were the best hybrids and Ofogh × BC-Roshan, Ofogh × Sorkh-Dane and Anfarm9 × BC-Roshan were the worst hybrids in most traits. Hayman's variance analysis showed that the additive and non-additive component of variance were significant in all of the traits. Based on Hayman's variance analysis, the heterosis (b1 component was significant) and unequal frequency of dominant and recessive alleles (b2 component was significant) were seen in most traits. Based on Hayman's variance analysis, the specific combining ability (b3 component was significant) of all traits was significant and emphasized the results of Griffing analysis. The results of this research indicate that for the introduction of a new variety or varieties in the Southern Khorasan region, it is recommended to use the local variety Sorkh-Dane in crossing in the figure. 

 The present study showed that although the local cultivar Sorkh-Daneh does not have a high economic yield, but it has a high general and specific combining ability in mating with other cultivars. Therefore, it is recommended to use this local cultivar in mating with other cultivars so as not to be forgotten.

Maize (Zea mays L.) is the fourth most important cereal after wheat, barley and rice in Iran (Ahmadi et al., 2018). Given the future demand of corn as a food for humans and as a feed for livestock, there is a continuous need to evolve new hybrids with high yield. To achieve this, combining ability study is one of the best options (Reddy Yerva et al., 2016). Griffing diallel method (Griffing, 1956a;b) is one of the methods that examines how genetic control of traits in parents. It also evaluates the general and specific combining ability of parents and hybrids. The purpose of this study was to estimate the general and specific combining ability of parents and hybrids.

In order to estimate the gene action and heritability of important agronomic traits, five S7 maize lines were crossed in a 5×5 half-diallel and F1 hybrids derived from them were cultivated in a randomized complete block design with three replications at the Research Farm of Graduate University of Advanced Technology, Kerman, Iran in 2017. Number of ear, grain number per row, grain row number, grain number per ear, ear length, 100-grain weight and grain yield per square meter were evaluated. Analysis of data for general and specific combining ability was carried out following Griffing (1956) method IV model I using DIALLEL-SAS05 program (Zhang et al., 2005).

Analysis of variance showed that there was a significant difference between genotypes for all studied traits that showed the role of additive and non- additive effects in controlling these traits. The low ratio of GCA variance to SCA for the grain row number and number of ear traits, and in other words, the lack of significant GCA variance of these traits showed that genetic control of these traits has a non-additive effect. General (GCA) and specific (SCA) combining ability variances for grain number per row, grain number per ear, ear length, 100-grain weight and grain yield per square meter were significant at 1% probability level, indicating the control of these traits by additive and non-additive effects of genes with a greater proportion of additive gene effects.

The results of this study showed that although genes with both additive and non-additive effects played a role in controlling of yield and its component traits. In controlling traits of ear number and rows, the role of non-additive effects was greater. Whereas, other traits were more controlled by the additive gene effects. The Line14 had positive and significant GCA for the yield trait and most of its related traits, which indicated that the line could be used in breeding programs to improve yield and increase it. The results also showed that the P1 × P2 and P3 × P5 crosses had positive and significant SCA for yield and its related traits, so these hybrids might be the best for improving and increasing maize grain yield.

Maize (Zea mays L.) is considered as one of the most important cereals in the field of world production. Water stress due to water shortages and its various forms is one of the main and most common limiting factors of crop yield, especially in arid and semi-arid regions of the world. Therefore, in corn, identification, selection and use of tolerant cultivars against drought stress in order to prevent the reduction of crop yield is considered as one of the most important and essential issues in breeding programs. Breeding of high-yield and good quality cultivars is one of the main goals of the breeding program which requires comprehensive information about the genetic structure of the parents, as well as their general and specific combining ability, the level of heterosis, genes action, and their interaction with each other and the environment. Therefore, the present study was conducted to evaluate the gene effects, heritability and the control of yield and its components in drought stress conditions compared to normal conditions in corn. In order to select suitable breeding methods and take an effective step in the production of high yielding maize cultivars.

In order to estimate the gene action and heritability of important agronomic traits, five S7 maize lines in a 5×5 half-diallel cross with F1 hybrids derived from them in a randomized complete block design with two replications in two normal conditions (irrigation intervals of 5 days) and drought stress (8 days irrigation) were cultivated at the Research Farm of Graduate University of Advanced Technology, Kerman, Iran in 2017. Number of ear, grain number per row, grain row number, grain number per ear, ear length, 100-grain weight and grain yield per plant were evaluated in two conditions. The data were analyzed by analysis of variance and regarding the significance of the variance of treatments, the analysis was performed using Griffing's second method. In order to carry out the diallel analyzes by Griffing's second method in two normal and drought stress conditions and combined analysis of variance was used SAS command.

Combined analysis of variance showed that there was a significant difference between genotypes, environment and genotype×environment interaction for all studied traits, indicating the genetic differences between lines and corn hybrids. The results of combined variance analysis showed a significant interaction effects between general and specific combining ability with the environment, which indicates the different of inheritance of traits in each environment. The results of diallel analysis by second Griffing method under normal conditions indicated that the grain number per row, grain row number, grain number per ear and ear length more controlled by non-additive effects of genes, while these traits more controlled by additive effects of genes under water scarcity conditions.

The results of this study showed that although genes with both additive and non-additive effects played a role in controlling the traits, the contribution of each of these effects was different in controlling each of the traits. Also, the control of these traits was different in both normal and drought stress conditions, and the genes controlling these traits differed from environment to environment. The KSC704-S7-7 line showed positive and significant general combining ability for grain yield and most related traits in both conditions which can be used in breeding programs to improve grain yield and increase it. In addition, the P2×P4 cross under water scarcity conditions and the P1×P3 cross under normal conditions, which showed positive and significant specific combining ability for grain yield and most related traits, are introduced as the best hybrids for improvement and increase of maize grain yield for water scarcity and normal conditions, respectively.

Coriander is one of the most important medicinal plants which has been used in the pharmaceutical industry. GGE Biplot method is one of the suitable methods for analyzing data with bilateral structure. In this research, the GGE Biplot model was used to evaluate the combinability of coriander essential oil yield in Diallel cross progenies of six parental coriander genotypes including Isfahan, Hamedan, Bushehr, Mazandaran, Markazi, and Alborz in the F1 generation in different irrigation regimes and three experiments separately through randomized complete blocks design with three replications in each experiment during the growing season of 2016. The results of genetic variance analysis showed that the effect of general and specific compatibility for essential oil yield was significant, indicating the importance of additive and non-additive genetic effects for this trait. In this study, the role of non-additive gene was more conspicuous than those of additive gene in controlling the essential oil yield. Therefore, providing superior hybrids by utilizing breeding methods based on the test progeny will be effective to improve these traits. Also, the results of the Biplot graphic analysis indicated that parental genotypes of Mazandaran (P4) and Bushehr (P6) had large specific and general compatibility and can be used as suitable parents for crosses to develop high-yielding varieties in coriander.

To evaluate the general and specific combining ability of maize lines, five S7 maize lines and their offsprings were evaluated in randomized complete block design with two replications under normal and water deficit conditions at the research field of Graduate University of Advanced Technology, Kerman, Iran, in 2017 and grain yield and its components were measured. The results of analysis of variance indicated that there was a significant difference between lines as well as general and specific combining ability of parents and hybrids. Based on the results of the diallel analysis by second Griffing’s method, number of grain per row, number of grain rows, number of grain per ear, ear length and 100 grain weight were more influenced by the additive effects than the non-additive gene effects, while the number of ear was more controlled by the non-additive gene effects and grain yield per plant was approximately controlled by equal portion of the additive and non-additive gene effects. The line KSC704-S7-1 showed significant and positive general combining ability for grain yield and more related traits under both water deficit stress and non-stress conditions, so this line can be used to improve grain yield in breeding programs. In addition, P1×P3 and P2×P5 hybrids showed significant and positive specific combining ability for grain yield and most related traits under water deficit stress and normal conditions, respectively, which are introduced as the best hybrids for improving maize grain yield under water deficit stress and normal conditions, respectively.

The most important purpose of alfalfa breeding programs is forage yield improvement. The objective of this study was to determine general combining ability (GCA) and specific combining ability (SCA) of alfalfa forage dry matter yield, plant height, number of stem, regrowth rate and leaf to stem ratio. A half diallel crosses (9×9) was performed by eight alfalfa ecotypes from different climatic regions of Iran and one cultivar from America. Experimental field was established in early autumn of 2013 which included 36 F1 hybrids with nine of their parents in a complete block design with three replications at Plant and Seed Improvement Institute, Karaj, Iran. The results of diallel analysis for two growth seasons (2014-2015) indicated high significant variation among crosses, GCA and SCA effects. Interactions of GCA and SCA with environment were significant for forage dry matter yield. The hybrids of Ghahavand × Nikshahri and Mohajeran × silvana indicated positive significant SCA for forage dry matter yield and regrowth, while, the hybrid of Kozare × Yazdi exhibited positive SCA for forage dry matter yield, plant height, re-growth rate and also leaf to stem ratio. This study indicated that the possibility of improvement forage yield and other agronomic traits through crosses among alfalfa ecotypes.

Information about combining ability of inbred lines and genetic variance components of different agronomic traits is a prerequisite for improving the productivity of sunflower hybrids. For this purpose, 20 hybrids obtained from the crosses between five cytoplasmic male sterile lines with four fertility restorer lines were evaluated in a randomized complete blocks design with three replications in the Agricultural Research Station, University of Tabriz, Tabriz, Iran in 2009. Analysis of variance indicated significant differences between the hybrids for most traits and therefore it was possible to estimate genetic variance components through line × tester method. Results showed that plant height, head diameter, 1000-seeds weight and oil content were under the control of additive gene effects. Over dominance gene effects were observed for time of flower initiation, stem diameter and grain yield. This justifies the production of hybrid varieties. Male sterile line 52 and R50 restorer line had a better general combining ability for seed yield. Hybrids 52 × R26 and 222 × R50 had the highest specific combining ability. The results of this study indicated that due to existence of genetic variability for agronomic traits in genetic materials and presence of combinations with suitable combining ability, production of superior sunflower hybrids is feasible by selection and hybridization.

This study was carried out to investigate the genetic structure of the 36 maize hybrids established from eighteen female lines and two male testers according to line × tester method under normal irrigation and drought stress conditions. Two separate experiments، normal irrigation and drought stress at grain filling stage were performed in Moghan for two years، using a RBCD with three replications. The results showed that the effect of gene action could be both non-additive and additive in the expression of grain yield under both conditions. However، GCA/SCA variance ratio revealed that non-additive genetic variance was more important for grain yield than additive variance. Analysis of general combining ability indicated that the variation of combining ability of lines in non-water stress condition was higher than that in water stress condition. The reactions of general combining ability of lines in both conditions were not similar. Lines L8، L11 and L17 in normal irrigation and lines L15، L16 and L17 in stress condition showed better general combining abilities for grain yield. The K3653/2 tester showed better general combining abilities for grain yield in both conditions. The crosses such as L1×T1، L4×T1 and L8×T1 in normal irrigation condition and L9×T2 in drought stress condition showed better specific combining abilities for grain yield.

Extensive and deep root system play important role in wheat drought tolerance and yield in water deficient condition. Nevertheless، a little is known about root structure genetic. In this research، a half diallel mating design was generated from crosses between eight bread wheat cultivars to study the genetic of root system. Parents and F1 progenies were planted in cyclic stress condition in a randomized complete block design with four replications and root length، root weight، root number، shoot weight، root to shoot ratio، grain yield، plant height and peduncle height were measured. Results showed that additive and dominant effects were significant for all traits. However، additive-dominant model was not adequate for root number. Non-additive variation was more important in genotypic disparity of root length and root to shoot ratio. Consequently، bulk، single seed descent and double-haploid methods are recommended in breeding program for these traits. Additive variation had imperative effect on genotypic variation of root weight and plant height. Thus، despite of mentioned breeding methods، pedigree and back-cross are recommended for these traits. Cultivar Roushan had an appropriate root system and high general combining ability for the root system traits. Accordingly، in breeding programs for developing root system، Roushan is recommended as one of the mating parents.

Combining ability and heritability of yield and yield components of sunflower(Helianthus annuus L.) breeding lines was studied using line × tester analysis. Eightlines and six testers which were tolerant to plasmopara (Plasmopara halstedii) diseasewere crossed in line × tester method. 48 F1 single cross combinations along with theirparents and two checks including Azargol and SHF81-85 were planted in simple latticedesign with two replications. The results of analysis of variance revealed significantdifferences among the genotypes for all the traits including plant height, life-cycleduration, duration of flowering, grain yield, seeds per head and oil yield. Line × testeranalysis based on Comstock and Robinson design II displayed significant effects ofgenotypes, parents and hybrids for all the studied traits. For growth period, RF81-25,AF80-488/1/2/1 had significant negative general combining ability effects. For durationof flowering, RF81-30, AF80-533/1/1/1 had also significant negative general combiningability effects. For seeds per head, RF81-25, AF80-488/1/2/1 and also for seed yield andoil yield, RF81-150/1 and AF80-488/1/2/1 maintained significant positive generalcombining ability effects. The crosses including AF80-460/2/1/1× RF81-25 and AF-6937×RF81-30 had significant positive specific combining ability for seed and oil yield.Maximum heterosis effects for seed yield were belonged to AF80-960×RF81-25.

Breeding for drought tolerance is one of the most efficient ways for preventing yield loss in dry conditions. Diallel method is one of the best methods for genetic evaluation of germplasm before starting of breeding program. In this experiment seven bread wheat genotypes including old genotypes and elite lines were crossed in a half diallel mating design. Parents and F1s were planted at stress and normal condition in a RCBD design with three replications. In addition to pheonologic recording, morphological traits and grain yield were measured after harvest. Analysis of variance for diallel experiment showed that the effect of GCA effect was significant for all traits that imply there is significant additive effect in controlling of all traits. Results showed that each genotype is good considering one or some traits. Using biplot analysis, parents with high SCA were recognized for different traits. For spikelets number per ear, ear number and thousand weight crosses Kavir×Shiraz, Sardari×Shiraz and Azar2×WS-82-9 had the highest SCA. Mather and Jinks graphical analysis showed the adequacy of additive-dominance gene action model. Degree of dominance was between from 0 to 1 for most traits which showed the gene action is almost partial dominance. Some genotypes like WS-82-9, Sardari and Kavir can be used for improving of traits thousand weight, ear number and spikelets in ear in both conditions, respectively. Also WS-82-9 is an elite line that can be acceptable genotype for dry condition.

A study was conducted to investigate the genetic variance components and the combinig ability of sunflowers lines at the Seed and Plant Improvement Institute, Karaj, IRAN in 2006. A total of 41 genotypes including 2 CMS, 13 restorer and their 26 corresponding hybrids were evaluated in a line × tester approach. The analysis of variance indicated that significant differences existed among genotypes for all of the studied traits except the days from sowing to emergence. The significance of the parents vs crosses variance indicated the presence of heterosis for days to maturity, diameter of head, grain yield and oil yield. The effect of parents was significant for most of the traits except for number of leaves, grain and oil yield. The effect of lines was significant for days to 5%, 50% and 75% flowering, days to maturity, number of leaves, length and width of leaf, plant height and grain yield. The testers effect was significant for plant height, grain yield, 1000 ‎grain weight and oil content. The effect of line × testers was significant only for 1000 ‎grain weight and days to 5% flowering. Based on general and specific combining abilities, CMS19 (tester) and CMSB × R7 were the best line and hybrid, respectively. The additive genetic effect was important in controling grain yield while dominance gene effect was important in controling 1000 grain weight and oil yield.

The crown wart disease caused by Urophelyctis leproides on sugar beet is very important in the growing areas of North Khuzestan influencing quantity and quality of the crop. The objectives of our research were to estimate general combining ability (GCA) and specific combining ability (SCA) of sugar beet lines as well as the gene action governing resistance to this disease. A randomized complete block design with three replications was used to evaluate six parents and their 15 F1 crosses. The method 2 and model 1 of Griffing and also Hayman method were used to estimate variance components. Resistance indices of the disease, ratio of gal weight to root weight and gal weight were measured on these genotypes.. The genotypic effects were significant for the disease indices. GCA and SCA were also significant indicating the importance of both additive and non-additive gene effects in controlling the disease resistance. The results from Hayman analysis showed complete-dominance for the traits under study and resistant genes appeared to be recessive. A recurrent selection program with new recombination in each generation for pyramiding valuable genes in inbred lines is suggested before selecting useful hybrid combinations.

A 5×5 half diallel cross set of chickpea (Arman، Hashem، ILC588، ICCV2 and ILC3979) was studied to estimate gene effects and genetic parameters of seven traits. According to diallel variance analysis، only additive genes effects were found significant for plant height، basal pod height and number of primary branches. In addition to the significant additive gene effects، dominant gene effects were significant for 100-seed weight، harvest index، seeds and seed yield per plant. The degree of dominance average (H1/D) 1/2 was lower than one for plant height، basal pod height and harvest index، indicating partial dominance but for 100-seed weight، seeds and seed yield per plant it was higher then one and for number of primary branches it was equal to one that indicating over dominance and complete dominance respectively. The narrow-sense heritability were high for harvest index (67%)، 100-seed weight (56%)، basal pod height (47%) and plant height (42%) indicating that great genetic gain could be achieved for these traits. Dominant direction was negative and high for all traits with exception of plant height and basal pod height; hence for these traits amplifier alleles were dominance.

A complete set of diallel crosses among seven durum wheat lines were used to study the genetics of yield and its components. Eight traits including days to heading, harvest index, grain number.spike-1, grain weight.spike-1, grain number.plant-1, plant height and grain yield.plant-1 were measured and recorded. Significant (P<0.01) differences were observed among genotypes for all the studied traits. Assumptions of Jinks-Hyman method were valid for harvest index, grain number.spike-1, grain weight.spike-1 and grain yield.plant-1. However, for the remaining traits, when one parent was excluded, the assumptions fulfilled. Based on the estimates of average degree of dominance and result of graphical analysis, the gene action for days to heading, was partial dominance, while grain weight. spike-1, plant height, fertile tiller number, grain number.spike-1, grain number.plant-1, grain yield.plant-1 and harvest index were controlled by over dominance gene action. Hayman analysis of variance indicated that additive (a) effects were significant for all of the studied traits, and dominance (b) effects significant for all of traits except day to heading. Maternal effects (c) were also significant for all of traits except plant height and fertile tiller number. Broad-sense heritability estimates ranged from 0.93 (for grain number.spike-1 and grain weight.spike-1) to 0.70 (for plant height). Narrow-sense heritability estimates ranged from 0.70 (for days to heading) to 0.30 (for fertile tiller number). The biplot indicated that entry Prion-1 had the highest GCA effect for grain weight.plant-1, fertile tiller number, grain number.plant-1, grain yield.plant-1 and harvest index. However, it had the lowest GCA for plant height and days to heading. Therefore, this genotype can be considered as suitable parent in durum wheat breeding programs

In order to compare of inheritance, combining ability, heterosis and genes action in the genetic control of 1000-kernel weight, grain per spike, grain yield per spike and grain yield per plant in bread wheat genotypes under drought stress conditions, an experiment was conducted on eight genotypes using fixed method 2 of Griffing. Exception mean squares of grain per spike at specific combining ability (SCA), other traits were significant differences for general and specific combining abilities. It states important of inheritance additive and dominance gene effects under drought stress conditions. The GCA/SCA ratio was significant for grain per spike. For exception of grain per spike, non-additive gene effects were more important than additive. It is concluded that genetic improvement of grain per spike under drought stress conditions is possible at early generations by selecting from the best crosses, while selection for another traits is better that delayed until advanced generations and increase of its heritability.

Inheritance of yield and its contributing characters in rapeseed (Brassica napus L.) was studied in a 8×8 diallel cross through Griffing and Jinks-Hayman analyses. Both general combining ability (GCA) and specific combining ability (SCA) were highly significant for seed yield, seed weight and branches per plant, while only GCA for seeds per pod and oil content and only SCA for pods per plant and days to maturity were significant. Both Griffing and Jinks-Hayman analyses showed that seed yield, seed weight and branches per plant were genetically controlled by both additive and non-additive gene actions. Overdominance gene action was observed for seed yield and its increasing was controlled by dominant alleles. Additive gene action was important for seeds per pod and oil content, while pods per plant and days to maturity were governed by non-additive gene action. Relatively high narrow-sense heritabilities were estimated for seeds per pod and seed weight indicating that a considerable selection response is expected for these characters in breeding programs. The results suggested that RGS003 with the highest GCA for seed yield could be used as a tester in topcross trials and 19H×Option500 with the highest SCA and heterobeltiosis could be applied in hybrid breeding.

In order to compare of inheritance، combining ability، heterosis and genes action in the genetic control of flag leaf area، leaf relative water content and grain filling rate in bread wheat cultivars under drought stress conditions، a study was conducted on eight cultivars using method 2 in fixed model of Griffing. General combining ability and specific combining ability mean of squares were highly significant for all the traits with the exception of specific combining ability mean of squares for leaf relative water content that designated importance of both additive and dominance gene effects in inheritance of traits studied in drought stress conditions. The general combining ability mean of square/specific combining ability mean of square ratio was not significant for all the traits. The results of this study showed that non-additive genetic effects were found to be more important than additive effects in genetic control of all the traits. In conclusion، genetic improvement of flag leaf area، leaf relative water content and grain filling rate in drought stress conditions at early generations will have low genetic gain. Therefore، selection for improvement of these traits is better that delayed until advanced generations and increase of its heritability.

To study the inheritance of drought tolerance in traits in bread wheat, 7 cultivars of bread wheat with their F1 progeny produced through a half diallel mating design, were planted in a randomized complete block design with 3 replications in normal and drought condition in Seed and Plant Improvement Institute Karaj, in year 2004. Analysis of variance showed significant difference for all the traits in normal and drought conditions at 1% probability level except for 2 traits (grain filling period and grain filling speed) in drought conditions. Diallel analysis revealed that general combining abilities were significant for all the traits in normal and drought conditions at 1% level of probability except for the number of spikes in plant in drought condition. The specific combining abilities were significant for all the traits at 1% level of probability except days to maturity in the two environments. Additive and non – additive effects were effective in controlling all traits and increase in the most of the traits was controlled with dominant alleles. Two traits (number of fertile spikelets, extrusion peduncle length) and grain yielding spikes exhibited the most broad sense in normal and drought conditions respectively.

Production of high yielding hybrid cultivars is among the main objectives of breeding programs in sunflower and on evaluation of the combining ability of the inbred lines necessary to select for the appropriate parental lines for production of hybrid cultivars. This study was conducted to investigate the general and specific combining ability and the mode of inheritance for agronomic and seed quality traits in some inbred lines of sunflower. Nine inbred lines of sunflower were each crossed with three male sterile inbred lines and then their hybrids (27 hybrids) evaluated for agronomic and seed quality traits. The data were analyzed based on the factorial model (Design II of Comstock and Rabinson) in a randomized complete block design of two replications. The results indicated that the additive genetic effects were more important than the non-additive effects of genes in the genetic control of days to flowering, days to maturity and seed oil content. The specific combining ability values for days to maturity and seed oil content varied from -3.67 to 4.50 days and from -2.89 to 2.42%, respectively. Both additive and non-additive effects of genes were important in inheritance of plant height, head diameter, 1000-seed weight, seed and oil yields with the range of specific combining ability (in hybrids for these traits) being -10.40 to 14.5 cm, -2.38 to 2.49 cm, -9.83 to 7.70g, -802 to 836 kg/ha and -320 to 343 kg/ha, respectively. The existing genetic variation for general and specific combining ability for agronomic and seed quality traits indicate that this genetic variation can be well used for production of high yielding and high seed quality hybrid cultivars.