فهرست مطالب

Crop Breeding Journal - Volume:6 Issue: 2, Summer-Autumn 2016

Crop Breeding Journal
Volume:6 Issue: 2, Summer-Autumn 2016

  • تاریخ انتشار: 1395/09/16
  • تعداد عناوین: 9
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  • A. Zakeri *, F. Afshari, M. Yasaie, A. R. Nikzad, S. Rajaei Pages 1-8
    Stripe rustis the most important disease of wheat in many wheat growing areas in Iran. Good knowledge of thegenetic basis of resistance to stripe rust in commercial bread wheat cultivars and selected elite lines is an important objective in wheat breeding programs. This study aimed to identify resistance genes and modes of inheritance of stripe rust resistance in recently released Iranian commercial wheat cultivars (Aflak, Parsi, Sivand, Uroum, and Pishgam) and elite bread wheat lines (M-84-14 and M-83-6). Crosses were made between these cultivars and elite lines with Avocet S and the F1, F2, and F3 generations were developed. Two F3-derived families (one adult plant stage and one seedling stage), as well as parents and controls, were grown under field and greenhouse conditions and inoculated with stripe rust pathotypes 134E158 A, 166E150 A, and 6E150 A, Yr27. The adult plant responses of parental cultivars Aflak, Uroum, Parsi, Pishgam, Sivand, and elite lines M-84-14 and M-83-6 to stripe rust in the field were 40MR, 10R, 50M, 10R, 50MS, respectively, in 2011, and 60MR, 5R, 40MR, 30MR, and 40M, respectively, in 2013. Cultivars and elite lines were resistant to stripe rust at the seedling stage test. Avocet S was susceptible at both adult plant and seedling stages. In addition to the seedling resistance responses of the parents, frequencies of F3 lines for each of the crosses in both adult plant and seedling stages conformed well with those expected for segregating for a trait at two loci, indicating that all five cultivars and two elite lines carry two dominant seedling resistance genes that have so far been effective for controlling stripe rust in Iran.
    Keywords: bread wheat, genetic analysis, pathotype, resistance gene, stripe rust
  • M. Esmaeilzadeh Moghaddam *, M. R. Jalal Kamali, N. Soda, S. Sadre Jahani, M. Ghodsi Pages 9-16
    A field experiment was conducted at the Seed and Plant Improvement Institute Research Field Station in Karaj, Iran, during the 2009-10 and 2010-11 growing seasons to estimate genetic progress and the variation in penological and agronomic characteristics in 13 irrigated facultative/winter bread wheat (Triticum aestivum L.) cultivars released in Iran between 1943 and 2011. Trends of temporal variation of the traits measured revealed that grain yield and some related phonological and agronomic traits have increased in the more recently released cultivars. Thousand grain weight decreased slightly compared to older cultivars. Number of days to heading and anthesis decreased in new cultivars, butgrain-filling period and days to physiological maturity did not change. Spike length also increased but plant height decreased in more recently released cultivars. These changes may explain the increase in grain yield of newly released facultative/winter bread wheat cultivars.
    Keywords: agronomic characteristics, bread wheat, days to flowering, grain filling duration, thousand grain weight
  • S. Golkari *, R. Hagparast, E. Roohi, S. Mobasser, M. M. Ahmadi, K. Soleimani, G. Khalilzadeh, G. Abedi, Asl, T. Babaei Pages 17-31
    Genotype × environment interaction is an important and challenging issue for plant breeders in developing new improved varieties. This study aimedto estimate the impact of genotype × environment interactions for grain yield in winter wheat under rainfed conditions using the additive main effects and multiplicative interaction (AMMI) model, and to select genotypes with high grain yield, yield stability, and adaptation for cold rainfed environments in Iran. Twenty-two breeding lines and two commercial winter wheat cultivars, representing winter wheat-growing cold rainfed areas of Iran, were tested in eight locations over three crop cycles (2011-14). Environment was the pre dominant source of variation, accounting for 84.8% of the total sum of squares, with the remainder due to the genotype × environment interaction effect (which was almost four times that of the genotype effect). Average grain yield varied from 1125 to 1608 kg ha-1 across the 24 environments, with an average of 1385 kg ha-1. The AMMI biplots identified genotypes with wide and specific adaptation as well as environments with high and low genotype discrimination and characterization. Relative humidity, freezing days, and plant height were among the environmental factors and genotypic co-variables that contributed highly to genotype × environment interactions for grain yield. These findings could identify breeding lines as potential genetic resources for improving and stabilizing grain yield in winter bread wheat breeding programs for cold rainfed areas of Iran, through exploitingand minimizing thegenotype × environment interaction.
    Keywords: genotypic, environmental co, variables, grain yield improvement, specific adaptation, wide adaptation, winter wheat
  • A. Rezaeizad *, H. Shirani Rad Pages 33-39
    Drought causes significant reductions in crop productivity in many parts of the world, including Iran. Identifying genotypes tolerant to drought stress is therefore one of the foremost goals of crop breeding programs. This study investigated the effect of terminal drought stress on yield and yield components of new winter rapeseed lines, and identified new winter rapeseed lines tolerant to terminal drought stress. A field experiment was conducted to evaluate 17 new winter rapeseed lines and two commercial cultivars (Ahmadi and Opera) under three moisture conditions (optimum irrigation, elimination of irrigation from flowering stage, and elimination of irrigation from silique stage) during two cropping seasons (2012-13 and 2013-14) at the Agricultural Research Station of Islamabad-e-Gharb, Kermanshah, Iran. Drought stress significantly affected all measured traits except days to flowering and 1000-seed weight. Based on the average of three conditions, KS7, KR4, L183, Opera, and HW118 had higher seed yields. These lines (except Opera) also produced higher seed yields when irrigation was eliminated from the flowering and silique development stages, and were identified as winter rapeseed lines tolerant to terminal drought stress with high seed yield potential underoptimum irrigation conditions.
    Keywords: flowering, rapeseed, seed yield, silique, terminal drought tolerance
  • R. Karimizadeh *, A. Asghari, A. Chinipardaz, O. Sofalian, A. Ghaffari Pages 41-49
    Grain yield stability is an important feature of crop breeding programs due mainly to the high annual variation in mean yield, particularly in arid and semi-arid areas. Conventional statistical models of stability analysis provide little or no insight into patterns of genotype × environment (GE) interaction, though the genotype plus GE (GGE) biplot method can more effectively account for the under GE interaction patterns. This study evaluated the yield stability of 20 spring durum wheat genotypes grown in five different warm locations in Iran across four cropping cycles (2009-2013) and used GGE biplot analysis to evaluate the yield stability of the genotypes and test locations by climatic factors. The combined analysis of variance revealed that the main effects of genotypes, locations, and years were significant, as well as the corresponding interaction effects. A polygon view of GGE biplot indicated that there were three winning genotypes (G10, G8, and G20) in three mega-environments for durum wheat in rainfed conditions. An ideal test location view of the GGL biplot showed that Gachsaran is the most desirable test location; genotype evaluation at this location maximized the observed genotypic variation among genotypes for durum wheat grain yield. Useof GGE biplots facilitated visual comparisons and identification of superior durum wheat genotypes for each target location. Genotype G10 was better than the other genotypes and is recommended for warm rainfed spring durum wheat growing areas of Iran.
    Keywords: GE interaction, grain yield, multi, environment trials, stability
  • A. Faraji * Pages 51-57
    Seed yield in soybean (Glycine max L.) is a function of moisture availability and is highly related to environmental conditions such as rainfall and irrigation. This study aimed to investigate differences among soybean lines and varieties in terms of phenology, above ground dry matter, seed yield, and yield components under different moisture regimes conditions, and to analyze the relationship between phenological characteristics and seed yield. Forty soybean genotypes were grown in two field experiments exposed to different irrigation regimes for three growing seasons (2010–2012). Results showed that variation in the duration of phenological stages was a determinant factor in increasing seed yield. There was a positive linear relationship between days to flowering and number of pods per plant, explaining 79 and 74% of the variation in seed yield under control and stress conditions, respectively. For both control and stress conditions, number of seeds m-2 was correlated with days to flowering and pod set. There were both linear positive and polynomial relationships between days to maturity and above ground dry matter at maturity, explaining 84 and 74% of the variation under control and stress conditions, respectively. These results suggest that’ soybean breeding programs in Iran should focus more on the duration of phenological stages in developing superior soybean genotypes for both stress and optimal conditions.
    Keywords: above ground dry matter, developmental stage, drought, flowering, seed yield
  • M. Mohammadi *, H. Ghojigh, H. Khanzadeh, T. Hosseinpour, M. Armion Pages 59-66
    Selecting bread wheat (Triticum aestivum L.) genotypes with wide adaptation across various test environments is important for enhancing the adoption rate of newly released wheat cultivars for rainfed spring wheat growing areas of Iran. This study analyzed the grain yield of 18 bread wheat genotypes at four dryland locations in Iran during the 2010-11, 2011-12, and 2012-2013 cropping cycles using the AMMI (additive main effects and multiplicative interaction) model. The biplot of AMMI-1 and AMMI-2 models facilitated the visual evaluation and identification of suitable genotypes, which is useful for genotype recommendation and mega-environment determination. Combined analysis of variance (ANOVA) revealed significant genotype × environment interaction for bread wheat yield. According to the AMMI-2 biplot, there were six best genotypes and five best mega-environments. The AMMI-1 model indicated that genotypes G2, G5, G9, G13, G14, G16, and G17 were superior, with moderate yield and yield stability, based on the lowest genotype × environment interactions. Genotypes G1 and G15 performed successfully in Khorramabad and Gonbad (two distinct mega-environments), respectively. The AMMI model was a useful tool for identifying yield stability of spring bread wheat genotypes for rainfed spring wheat growing areas of Iran. The significant genotype × environment interaction suggested that breeding strategies for specific adaption genotypes in homogeneously grouped environments should be considered in the national rainfed spring bread wheat breeding program in Iran.
    Keywords: adaptability, biplot, drought, dryland, grain yield
  • T. Basaki *, M. Khayam Nekouei, R. Choukan, M. Mardi Pages 67-78
    Pomegranate, Punica granatum L., is one of the oldest cultivated fruit species. This study used morphological data and a set of simple sequence repeat markers to investigategenetic diversity among 202 Iranian pomegranate accessions during the 2010 and 2011 growing seasons at Saveh Research Station, Saveh, Iran. Principal component analysis showed that leaf traits were predominant in the first and second component during both years, indicating that these traits are not only useful in assessing genetic diversity, but also for characterizing pomegranate germplasm. There was high correlation between the length of style and flower shape, implying that these traits are directly associated with tree performance. There was also close correlation between leaf length with leaf width, and total leaf length as well as and flower traits such as flower diameter and width. Twenty-three alleles (ranging from two to nine per locus) were detected using seven SSR markers with ABRII-MO26 showing the highest level of polymorphism. The average expected heterozygosity and mean PIC values were 0.36 and 0.34, respectively.Cluster analysis showed a simple matching coefficient ranging from 0.24 to 1 indicating high genetic diversity. Punica microsatellite markers and morphological characters revealed a relatively high genetic diversity among 202 pomegranate accessions. This great variation in the pomegranate collection of Saveh Research Station ensures the future of pomegranate breeding programs in Iran. Strategic research on the base collection and characterization of accessions provides useful information to breeding programs and will enhance the development of core collections.
    Keywords: genetic diversity, heterozygosity, molecular markers, morphological characters, pomegranate
  • M. Tatari *, A. Ghasemi, A. Mousavi Pages 79-85
    Identifying and selecting superior genotypes in native germplasm is one method for breeding fruit trees. Five different ecotypes of Jujube (Ziziphus jujuba Mill.) were collected from different regions of Isfahan province, Iran, for evaluation of their morphological and pomological traits during 2011-13. Results showed that quantitative traits were more significant within ecotypes. ‘‘Najafabad’ ecotype had the highest dimensions of leaves (48×28 mm), fruit weight (2.1 g), and stone weight (0.35g). The largest fruit width (17mm) and peduncle length (13mm) was observed in ‘Ardestan’ ecotype, whereas the largest fruit length (22mm) was observed in ‘Dehaghan’ ecotype. According to the results, the smallest size and weight of fruit, stone weight, and the longest and highest number of annual thorns in shoots were measured in ‘Kouhpayeh’ ecotype. Results showed significant negative and positive correlations between some traits. According to the cluster analysis, ecotypes with desirable traits of fruit were placed in separate clusters from other ecotypes. ‘Najafabad’ ecotype, followed by ‘Ardestan’ and ‘Dehaghan’ ecotypes, can be recommended as promising ecotypes for establishing Jujube orchards and use in Jujube breeding programs in Iran.
    Keywords: cluster analysis, ecotype, genetic variation, Jujube, morphological traits