@article { author = {Mohammadi, M. and Karimizadeh, R.}, title = {Insight into heat tolerance and grain yield improvement in wheat in warm rainfed regions of Iran}, journal = {Crop Breeding Journal}, volume = {2}, number = {1}, pages = {1-8}, year = {2012}, publisher = {Seed and Plant Improvement Institute}, issn = {2008-868X}, eissn = {2423-4605}, doi = {10.22092/cbj.2011.100365}, abstract = {Terminal heat and drought are the main constraints for wheat production in the vast and diverse semi-tropical rainfed regions of Iran. High temperature stress during wheat’s reproductive stage is particularly detrimental, reducing both individual kernel weight and kernel number. Identification of adapted genotypes can improve grain yield and its stability under heat stress conditions. Selection to improve grain yield and adaptation to abiotic stress is difficult, making the use of indirect selection for grain yield attractive to plant breeders. Experimental results in diverse environments have indicated remarkable variation for canopy temperature and a significant negative correlation with grain yield, particularly in warmer environments. There is also evidence that adapted wheat genotypes are able to maintain high individual kernel weight despite heat stress. Two recently released wheat cultivars for warm rainfed regions of Iran have shown high grain weight and cooler canopy temperature under different environmental conditions. Therefore, it is concluded that plump grain and cooler canopy temperature are essential traits for the adaptation of wheat genotypes in warm rainfed regions of Iran.}, keywords = {canopy temperature,drought,grain-filling period,source-sink limitation,thousand-kernel weight}, url = {https://cbjournal.areeo.ac.ir/article_100365.html}, eprint = {https://cbjournal.areeo.ac.ir/article_100365_08d05f68777988ef00235ca82d2e23a5.pdf} } @article { author = {Ghazvini, H.}, title = {Adult plant resistance and yield loss in barley cultivars inoculated with a newly-emerged pathotype of Bipolaris sorokiniana in Manitoba, Canada}, journal = {Crop Breeding Journal}, volume = {2}, number = {1}, pages = {9-15}, year = {2012}, publisher = {Seed and Plant Improvement Institute}, issn = {2008-868X}, eissn = {2423-4605}, doi = {}, abstract = {Spot blotch caused by Bipolaris sorokiniana is a serious disease of barley in western Canada. It has become the predominant barley leaf spot disease in the province of Manitoba, Canada, since 2001. A new pathotype of B. sorokiniana with virulence on seedlings of ‘resistant’ six-rowed barley cultivars grown in Manitoba was recently identified. To determine the adult plant infection response of barley genotypes to this newly identified pathotype and to assess the extent of the damage and grain yield loss the new pathotype can cause in barley genotypes, a field trial was conducted on six barley genotypes that were inoculated with a high virulence (HV) isolate representative of the newly identified pathotype (WRS 1986) and a low virulence (LV) isolate (WRS 1949) of the pathotype. The mean infection responses of the adult barley plants inoculated with the HV isolate were generally higher than those induced by the LV isolate. Average grain yield losses caused by the HV and LV isolates were 11% and 6%, respectively. Barley line TR 251 and cultivar Stander sustained lower reductions in yield than other cultivars when inoculated with the newly emerged B. sorokiniana isolate, indicating they may possess higher levels of adult plant resistance.}, keywords = {Cochliobolus sativus,Growth stage,infection response,spot blotch,virulence}, url = {https://cbjournal.areeo.ac.ir/article_110358.html}, eprint = {https://cbjournal.areeo.ac.ir/article_110358_d9f5c72e6e33a9971e38dcd50e59be4c.pdf} } @article { author = {Ghanavati, F. and Nematpajooh, N. and Khosrow Chahli, M. and Safaei Chaeikar, S.}, title = {Cytological evaluation of annual species of the Onobrychis genus in Iran}, journal = {Crop Breeding Journal}, volume = {2}, number = {1}, pages = {17-24}, year = {2012}, publisher = {Seed and Plant Improvement Institute}, issn = {2008-868X}, eissn = {2423-4605}, doi = {10.22092/cbj.2012.100412}, abstract = {The genus Onobrychis is an important forage crop consisting of approximately 130 annual and perennial species. In this study, 13 populations of five Onobrychis species were analyzed. The basic chromosome number varied from x=7 to x=8. According to Stebbins’ classification, populations such as O. aucheri subsp. psammophila, O. crista-galli (1) and O. crista-galli (2) were classified in symmetric class B, while the others were classified in A. Based on interchromosomal symmetry, O. aucheri subsp. tehranica and O. crista-galli (1) had the most asymmetrical and evolutionary karyotype, and O. crista-galli (6) had the most symmetrical karyotype. Based on intrachromosomal symmetry, O. crista-galli (6) had the most asymmetrical karyotype. Populations were divided into three classes by cutting dendrogram resulting from cluster analysis (Ward) using six parameters (SA, LA, TL, AR, r-value, CI). The greatest distance observed was between O. crista-galli (3) and O. crista-galli (5), while the smallest distance was between O. crista-galli (2) and O. crista-galli (6). Populations were separated into three classes using two indices (A1 and A2). The greatest distance observed was between O. crista-galli (6) and O. aucheri subsp. tehranica, while the smallest distance was between O. crista-galli (5) and O. crista-galli (3).}, keywords = {number of chromosomes,interchromosomal symmetry,intrachromosomal asymmetry,asymmetrical karyotype}, url = {https://cbjournal.areeo.ac.ir/article_100412.html}, eprint = {https://cbjournal.areeo.ac.ir/article_100412_bde3c581c1563d0800aff0abef3db5b2.pdf} } @article { author = {Ghanavati, F. and Amirabadizadeh, H.}, title = {Pollen grain morphology in Iranian Hedysareae (Fabaceae)}, journal = {Crop Breeding Journal}, volume = {2}, number = {1}, pages = {25-33}, year = {2012}, publisher = {Seed and Plant Improvement Institute}, issn = {2008-868X}, eissn = {2423-4605}, doi = {10.22092/cbj.2012.100413}, abstract = {Pollen grain morphology of 15 taxa of the Hedysareae tribe distributed throughout Iran was studied using light and electron microscopy to identify major taxonomical characteristics of pollen grains. The pollen grains were tricolpate and tricolporate, prolate and perprolate. The ectocolpi were elongated, shallow or deep, narrowing at the poles. The colpus membrane was covered by large granules. Ornamentation was reticulate, and lumina differed in shape and size. In equatorial view, the pollen grains were elongated, elliptic to rectangular-obtuse, while in polar view they were circular, triangular-obtuse or triangular and trilobed. Two pollen types with two tentative subtypes were identified based on ornamentation and polar view.}, keywords = {Pollen grains,Hedysareae,ornamentation,taxonomical characteristics}, url = {https://cbjournal.areeo.ac.ir/article_100413.html}, eprint = {https://cbjournal.areeo.ac.ir/article_100413_95ece4932de91bba6cf6fae9b3444135.pdf} } @article { author = {Ramezanpour, S. and Mohammadi, M. and Navabpour, S. and Soltanloo, H. and Kalateharabi, M. and Kia, S.}, title = {Genetic analysis and heritabilities of resistance to Mycosphaerella graminicola in wheat}, journal = {Crop Breeding Journal}, volume = {2}, number = {1}, pages = {35-42}, year = {2012}, publisher = {Seed and Plant Improvement Institute}, issn = {2008-868X}, eissn = {2423-4605}, doi = {10.22092/cbj.2012.100414}, abstract = {Septoria tritici blotch is an important wheat disease in many areas of the world including Iran's warm, humidregions. In this study, crosses were made between resistant breeding line BOBWHITE#1/FENGKANG andcommercial cultivars Moghan3, Koohdasht, Tajan and Morvarid, and derived F1, F2, BC1 and BC2 generations were used to determine the genetic control of necrosis, pycnidia traits and the area under disease progress curve (AUDPC) in seedlings under greenhouse conditions using generation mean analysis. The cultivars and derived populations were evaluated using a randomized complete block design with three replications. Significant differences among generations were found for all traits, and genetic analyses of those traits were performed. Results showed that additive, non-additive and epistatic effects played roles in controlling all traits. The role of dominance effects and dominance × dominance interaction was much greater in controlling the studied traits. Therefore, hybridization methods and selection in the final generation are recommended for improving resistance to septoria tritici blotch.}, keywords = {Mycosphaerella graminicola,dominance effect,heterosis}, url = {https://cbjournal.areeo.ac.ir/article_100414.html}, eprint = {https://cbjournal.areeo.ac.ir/article_100414_6144bd309fd7edd2da7267ada5edefc1.pdf} } @article { author = {Najafi-Mirak, T.}, title = {Evaluation of resistance to Sunn pest (Eurygaster integriceps Put.) in wheat and triticale genotypes}, journal = {Crop Breeding Journal}, volume = {2}, number = {1}, pages = {43-48}, year = {2012}, publisher = {Seed and Plant Improvement Institute}, issn = {2008-868X}, eissn = {2423-4605}, doi = {10.22092/cbj.2012.100416}, abstract = {Sunn pest (Eurygaster integriceps Put.) is one of the major pests of wheat in Iran. Identification of resistantcultivars is an effective integrated pest management (IPM) strategy. To identify the genetic response of wheat and triticale to Sunn pest, and determine the relationship between resistance and morpho physiological traits, eight bread wheat breeding lines/cultivars, four durum wheat lines, three triticale lines and five synthetic wheat lines were evaluated for resistance to Sunn pest. The response of these genotypes to Sunn pest was evaluated in the field under artificial infestation in cages using a randomized complete block design with three replications. At heading, eight adult insects were released into each cage (30×40×120 cm) and 30 nymphs were released at the grain-filling stage. Spike damage (%) and grain damage (%) were recorded. An analysis of variance revealed significant differences among the genotypes for spike injuries caused by adult insects. Cultivar Falat (1.8% spike damage) showed the least damage and is considered the most resistant genotype. Durum line D-81-15 and Triticale-1, each with 2% spike damage, were more resistant than the other genotypes. Based on grain damage caused by nymphs of Sunn pest, Shiraz, with 13% damage, was the most susceptible genotype. In this study, no significant correlationwas observed between resistance to Sunn pest and the measured morpho-physiological traits. Nymph feeding on grain reduced grain protein content, Zeleny sedimentation volume, bread volume, flour water absorption rate, gluten index and grain gluten elasticity.}, keywords = {Bread quality,Durum wheat,spike damage,grain damage,resistance}, url = {https://cbjournal.areeo.ac.ir/article_100416.html}, eprint = {https://cbjournal.areeo.ac.ir/article_100416_a28747b098c6da2bc9132a46ef1fd3c6.pdf} } @article { author = {Ghodrati, G. R.}, title = {Response of grain yield and yield components of promising genotypes of spring rapeseed (Brassica napus L.) under non-stress and moisture-stress conditions}, journal = {Crop Breeding Journal}, volume = {2}, number = {1}, pages = {49-56}, year = {2012}, publisher = {Seed and Plant Improvement Institute}, issn = {2008-868X}, eissn = {2423-4605}, doi = {10.22092/cbj.2012.100417}, abstract = {To assess moisture stress tolerance at the reproductive growth stage in 11 promising genotypes of spring rapeseed (Brassica napus L.), two field experiments were conducted in two growing seasons (2008-2010) at the Agricultural Research Center of Safiabad, Dezful, Iran. Genotypes were sown under two non-stress (well-irrigated) and moisture stress (irrigation ceased at flowering) conditions using a randomized complete block design with three replications for each moisture regime. Agronomic traits (plant height, number of siliques per plant, number of grains per silique, test grain weight, grain yield, days to flowering, days to maturity and oil content) were measured and recorded. Genotype and moisture regime main effects were highly significant for all the measured traits. Moisture regime × genotype interaction was also highly significant for silique per plant, flowering period and oil content traits, suggesting different responses of genotypes in different moisture conditions. Grain yield reduction (10.9%) in genotype 5 (G5) under moisture stress conditions was significantly lower than in all other genotypes. Genotype 11 (G11) produced the highest oil content, which was significantly higher than that produced by other genotypes in either regime. A significant positive correlation coefficient (r = 0.578*) was observed between grain yield and oil content under non-stress conditions. Grains silique-1 had a significant negative correlation with date of maturity under well-watered (r = -0.711**) and moisture stress (r = -0.634*) conditions. Calculated stress tolerance index (STI)varied from 0.47 for G7 to 1.01 for Hyola401. G1 and G4 with high STI values were identified as highly tolerant genotypes. This was in agreement with conclusions reached based on agronomic traits. It is concluded that G1 with 1974 kg ha-1 and G4 with 2511 kg ha-1 grain yields could be suitable substitutes for cv. Hyola401 under moisture stress and non-stress conditions, respectively.}, keywords = {agronomic traits,drought tolerance,Grain yield,oil content,Stress tolerance index}, url = {https://cbjournal.areeo.ac.ir/article_100417.html}, eprint = {https://cbjournal.areeo.ac.ir/article_100417_33ed157cb6b45eb404c895bb7a8c15dc.pdf} } @article { author = {Darvishzadeh, R. and Hatami Maleki, H.}, title = {Analysis of genetic variation for morphological and agronomic traits in Iranian oriental tobacco (Nicotiana tabaccum L.) genotypes}, journal = {Crop Breeding Journal}, volume = {2}, number = {1}, pages = {57-61}, year = {2012}, publisher = {Seed and Plant Improvement Institute}, issn = {2008-868X}, eissn = {2423-4605}, doi = {10.22092/cbj.2012.100419}, abstract = {To assess the genetic diversity for morphological and agronomic traits in Iranian oriental tobacco germplasm,100 oriental and semi-oriental tobacco genotypes from the Urmieh Tobacco Research Center collection were evaluated in the field using a simple square lattice design with two replications. Some agronomic traits were measured on five randomly selected plants in each plot. Genotypes were clustered into similar groups using UPGMA based on squared Euclidean distance after data normalization. Four distinct groups were established. Discrimination function analysis performed to determine the accuracy of the grouping developed by cluster analysis showed that the total success rate of grouping was 97%. Among developed groups, groups 1 and 4 had the maximum Mahalanobis distance value of 67.4. Results revealed that the first three discriminant functions were significant, and their standardized discrimination function coefficients indicated that among the studied traits, days to 50% flowering, dry leaf yield and number of leaves per plant were the most important for discriminating among tobacco genotypes.}, keywords = {cluster analysis,Discriminant analysis,Genetic diversity,Mayhalanobis distance,leaf yield}, url = {https://cbjournal.areeo.ac.ir/article_100419.html}, eprint = {https://cbjournal.areeo.ac.ir/article_100419_441fbb9ccd219dc198b8b6c529da6376.pdf} } @article { author = {Mohammadi, M. and Karimizadeh, R. and Hosseinpour, T. and Kalateharabi, M. and Khanzadeh, H. and Sabaghnia, N. and Mohammadi, P. and Hasanpour Hosni, M.}, title = {Analysis of genotype, environment and genotype × environment interaction in bread wheat in warm rainfed areas of Iran}, journal = {Crop Breeding Journal}, volume = {2}, number = {1}, pages = {63-70}, year = {2012}, publisher = {Seed and Plant Improvement Institute}, issn = {2008-868X}, eissn = {2423-4605}, doi = {10.22092/cbj.2012.100420}, abstract = {Stable performance of new improved bread wheat (Triticum aestivum L.) genotypes in multi-environment trials is important in crop improvement programs. In such trials, genotype evaluation and mega-environment identification are the most important objectives. The yield stability of 18 bread wheat genotypes was investigated through genotype (G) and genotype × environment (GE) interaction using the GGE biplot technique. Field experiments were conducted in 12 warm rainfed environments in Iran to characterize G × E interactions for grain yield of bread wheat genotypes. A combined analysis of variance across locations showed that both main effects (environment and genotype) and GE interactions werehighly significant. Principal component analysis was performed, and the first two principal components (PC1 and PC2) explained 45% and 26% of the total sum of squares, respectively; they were used to create GGE biplot diagrams. The polygon tool of the biplot suggested two bread wheat growing environments in warm dryland regions of Iran: a small one (Moghan) and a large one (Gachsaran, Gonbad and Khoramabad). Visualizing the mean and stability parameters of the genotypes in the biplot indicated that genotypes HAMAM-4 (G1) and CHEN/AEGILOPS SQUARROSA (TAUS)//BCN/3/VEE#7/4/PASTOR (G4) are adapted to warm rainfed areas of Iran. The vector view of the biplot showed that Gonbad, Khoramabad and Gachsaran were correlated, but had no association with Moghan. Finally, it was concluded that G1 and G4 showed high yield stability across environments and are, therefore, recommended for release in warm rainfed areas of Iran.}, keywords = {adaptability,drought,multi-environment trials,grain yield stability}, url = {https://cbjournal.areeo.ac.ir/article_100420.html}, eprint = {https://cbjournal.areeo.ac.ir/article_100420_e027aa993d2ec44927ba6ff08715836b.pdf} }