|
|
|
 |
Search published articles |
 |
|
Showing 4 results for Maize
Rasoul Banaei, Amin Baghizadeh, Saeid Khavari Khorasani,
Volume 3, Issue 1 (9-2016)
Abstract
In order to estimate the components of genetic variance and general and specific combining abilities of maize lines, an experiment was done using 8 S6 inbred lines as female parents and 2 male inbred lines as testers consisted of K1264/5-1 (early mature) and K3615/1 (late mature) using line by tester mating design based on randomized complete block design with three replications in two different conditions (Salt stress with Ec=5 dsm-1 and non-salt conditions) in research field of graduate university of advanced technology (Kerman, Iran) in 2014. Analysis of variance results showed significant differences among inbred lines for some of measured traits in both salt and non-salt conditions. Significant differences observed for line × tester mean-squares in non-salty condition for all measured traits except days to silking and physiological maturity. In salt stress condition, just for leaves number per plant and days to silking, line × tester effects were not significant. Additive variance for days to silking and physiological maturity in non-salt condition was more than dominant variance, therefore the additive to non-additive variance ratio was more than 1 and indicating emphasis on this matter too. Inbred line L6 had a significant positive GCA and the highest grain yield with 1455.785 and 789.107 kg/ha in non-salt and salt stress condition, respectively. The crosses (L4×T1=428.460 and L7×T1= 438,345) in non-salt condition and (L3×T1=438.345) in salt stress conditions had a positive significant specific combining ability. Finally, from all existed variation, the lines and line × tester effects were more important than tester effects that indicates transmission of diversity from lines to hybrids.
Razieh Azizian Mosleh, Mohammad Reza Abdollahi, Hassan Sarikhani, Asghar Mirzaie-Asl, Payam Pour Mohammadi,
Volume 7, Issue 2 (3-2021)
Abstract
Optimization of in vitro methods for the production of maize double haploids plays an important role in the breeding programs of this plant. In this study, the effects of 5-azacytidine on agronomic traits, androgenesis induction efficiency and also, DNA methyltransferase gene expression (AF229183.1) in two growth stages of maize were investigated. This experiment was performed as factorial based on a completely randomized block design with three replications. Two maize genotypes (DH5 × DH7 and ETMH-82) were considered as the first factor and treatment of maize seeds with 5-azacytidine (0, 5, 10, and 100 μM) was considered as the second factor. The maize seeds were sowed in the field and during the growth stages, various morphological and agronomic traits were recorded. In the anther culture experiment, the suitable anthers containing microspores at mid to late-uninucleate stages were selected and cultured in an YPm culture medium containing 1 mg/l 2, 4-D, and 2 mg/l BAP. Interaction effects of genotype and 5-azacytidine concentrations showed significant differences for the majority of studied traits except for number of kernel per ear row, kernel depth, plant diameter, number of leaves and number of ears. The highest amounts of 1000-kernel weight were obtained with treatments of 10 and 100 μM and the highest ones for grain yield and biological yield traits were obtained with 100 μM 5-azacytidine treatment for both genotypes. Seeds of DH5 × DH7 genotype treated with 5 μM 5-azacYtidine produced the highest mean number of embryo-like structures (0.1833) and regenerated plantlets (0.067) per each anther. Relative expression of DNA methyltransferase gene in maize seeds treated with different concentrations of 5-azacytidine showed a significant decrease in both genotypes and both growth stages compared to control plants (treated with 0 μM 5-azacytidine), that this decrease in gene expression could lead to improved androgenesis induction in anther culture of DH5 × DH7 genotype. However, despite the decrease in expression of this gene in two growth stages of ETMH-82 genotype, androgenesis induction was not observed in this genotype. The results of the present study can help to determine the role of epigenetic factors in androgenesis induction and improving the production of haploid plants in maize.
Mozhgan Shirinpour, Ehsan Atazadeh, Ahmad Bybordi, Saeid Aharizad, Ali Asghari, Ashkboos Amini,
Volume 10, Issue 1 (9-2023)
Abstract
Considering the importance of maize production and the impact of water deficit stress on reducing the yield of maize, estimating the genetic components and heritability of traits for determine the breeding method under water deficit stress is essential in breeding programs. The generations drived from a cross between two inbred lines of maize including B73 (maternal line) and MO17 (paternal line), SC704 (F1) as well as F2, BC1, BC2 and F3 generations in order to estimate the genetic effects and heritability of yield, yield components and morphological traits were studied. Seven maize generations using the generations mean analysis under the full irrigation, mild and severe water deficit conditions were evaluated. The experiment was conducted in the form of randomized complete block design with 20 replications per experimental unit during two cropping seasons (2018-2019) at the Agricultural Research Station of University of Tabriz. The results of two-year combined analysis of variance and mean comparisons under three different irrigation regimes showed that water deficit stress significantly reduced all of the studied traits (except root/shoot ratio). The generations mean analysis showed the high contribution of non-additive gene effects for the genetic control of grain yield, ear diameter, number of kernel row, ear weight (in full irrigation conditions), 100 grain weight, plant height, fresh shoot weight and biological yield traits. According to these results, selection in the advanced generations and the breeding method based on hybridization can be effective to improve these traits. Also, the significant contribution of additive gene effects in controlling the inheritance of ear length, ear weight (in both stress conditions) and root/shoot ratio traits indicated that selection in early segregating generations and inbred parents can be effective for breeding of these traits and taking advantage of additive variance. Hybrid SC704 and inbred MO17 compared with the inbred B73 showed the lowest variation percentage under the water deficit stress conditions, which indicated their high yield potential and stability in the stress conditions.
Maryam Ebrahimi, Reza Darvishzadeh, Amir Fayaz Moghaddam,
Volume 10, Issue 1 (9-2023)
Abstract
Protection of food security is one of the basic priorities of any country, which is achieved through the development and introduction of new, high-yielding and stress-resistant crop varieties. Considering the wide range of usage; human nutrition, livestock and poultry nutrition as well as use in industrial products production, maize is of special importance in agricultural development programs. To improve a trait with complex behavior and low heritability, indirect selection by other traits or a suitable index developed based on several traits can be used. In this research, 86 maize genotypes were cultivated in the form of randomized complete block design with three replications in the field in the Faculty of Agriculture, Urmia University under two normal and salt stress conditions. The measurement of the traits was done from the tassel appearance to kernel physiological maturity. In order to speed up genotype selection and increase the acuracy of selecting high yielding genotypes, four selection indices including Smith- Hazel, Pasek- Baker, Brim and Robinson were used and calculated. The results of present study revealed that selection based on the Smith- Hazel index with the highest selection efficiency (∆H) will increase the grain yield in normal and grain yield and plant height in salt stress conditions. This index, with its high correlation with the breeding value is introduced as a superior index. Based on this index, R59 and 6*/88 genotypes were introduced as the superior genotypes under normal and salt stress conditions, respectively. Nonetheless, these genotypes were recognized as the best genotypes considering the results of all other investigated indices. Identifying and introducing genotypes tolerant to salinity stress is of particular importance due to the expansion of saline lands and the limitation of access to water suitable for irrigation. Based on the above results, 6*/88 genotype is recommended for the development of promising hybrids for cultivation in areas with water or saline soil.
|
|
