Wild diploid goatgrass, Aegilops tauschii Coss., is the D-genome donor to hexaploid bread wheat. Goatgrass has been crossed with tetraploid durum wheat (Triticum turgidum var. durum L.) and hexaploid bread wheat (T. aestivum L. ssp. aestivum) to broaden the genetic base of bread wheat. We examined the contribution of main stem water-soluble carbohydrates (WSC) and current assimilates to grain yield in one goatgrass relative to those in one durum and four cultivars of bread wheat under well-watered and droughted field conditions across two years. Drought reduced grain yield and its components. Number of tillers per plant was higher in goatgrass, but 55% of tillers produced were sterile. Number of grains per spike was lower in goatgrass. Grain weight was the component severely limiting potential yield in goatgrass. Main stem WSC and concentration was lowest in goatgrass. Linear rate of grain growth in goatgrass was 20 and 17 mg spike−1 day−1 under well-watered and droughted conditions, whereas those in durum and bread wheats ranged from 55 to 73 and from 37 to 60 mg spike−1day−1, respectively. Current assimilates were the major source of carbon to fill the grains under both irrigation regimes. A large number of goatgrass accessions and adapted durum cultivars should be examined for grain yield and its components to identify promising accessions to be used in producing synthetics.
Four maize hybrids bred at the Cereal Research Non-Profit Company in Szeged were registered at the National Institute for Agricultural Quality Control (OMMI) during the period 2001-2004. The registration of five Szeged hybrids is expected on the territory of the European Union in 2005-2006. The hybrids are accompanied by specific production technological guides for commercial production based on the results of agronomy trials, so that the genetic potential of the hybrids can be utilised in practical farming to the highest possible extent. The specific agronomic traits of hybrids with different vegetation periods and genotypes are investigated. If a maize hybrid is to be recommended to farmers, it is necessary to know not only its yield potential, but also its yield stability. For this reason, investigations are also made on the effect of soil and climate on the grain yield potential of each hybrid individually.
Authors:E. Andeden, F. Yediay, F. Baloch, S. Shaaf, B. Kilian, M. Nachit, and H. Özkan
Vernalization and photoperiod response genes play a significant role in the geographical adaptation, agronomic performance and yield potential of crops. Therefore, understanding the distribution pattern and allelic diversity for vernalization and photoperiod genes are important in any wheat breeding program. In this study, we screened 63 bread wheat cultivars and 7 bread wheat landraces from Turkey for photoperiod (Ppd-D1) and vernalization genes (Vrn-A1, Vrn-B1, Vrn-D1 and Vrn-B3) using diagnostic molecular markers. The photoperiod insensitive dominant allele, Ppd-D1a, was present in 60% of wheat cultivars and 42% of landraces, whereas, all other genotypes carried the photoperiod sensitive allele Ppd-D1b as recessive allele. Twenty-four cultivars and two landraces contained recessive alleles for all four VRN loci, whereas 39 wheat cultivars and 6 landraces contained one or more dominant VRN alleles. The highest percentage of Turkish wheat cultivars contained the dominant Vrn-B1 allele followed by Vrn-D1 and Vrn-A1. Information for vernalization and photoperiod alleles in Turkish germplasm will facilitate the planning and implementation of molecular markers in wheat breeding programs. This information will be helpful to develop elite wheat cultivars carrying suitable vernalization and photoperiod alleles with higher grain yield potential and better quality suitable for different production environments through marker assisted selection.
After a decade of genetic manipulation and improvement, triticale stand out as a crop of high biomass and grain yield potential which generally surpass that of wheat. Its high productivity is most likely derived from high rates of carbon assimilation linked to stomatal physiology and probably low respiration rate. Being a derivative of rye, triticale has always been assumed to be relatively resistant to abiotic stress. The last review of triticale adaptation to abiotic stress as published by Jessop (1996) pointed at its general and specific fitness to harsh growing conditions. This review as based on additional data published in the last 20 years indicates that triticale retain good to excellent adaptation to conditions of limited water supply and problem soils which involve salinity, low pH, defined mineral toxicities and deficiencies and waterlogging. Despite the understandable expectations, freezing tolerance of triticale was not found to be up to the level of rye. The freezing tolerance of the rye complement in triticale is inhibited by unknown factors on the wheat parent genome. Any given triticale cultivar or selection cannot be taken a priori as being stress resistant. Research has repeatedly shown that triticale presented large genetic diversity for abiotic stress resistance and most likely this diversity has not yet been fully explored due to the very limited research and the small studied sample of the potential triticale germplasm. Triticale is a valuable stress tolerant cereal on its own accord and a potential genetic resource for breeding winter and spring cereals. Because of its high productivity and resilience it might become as important as wheat or better on a global scale if its grain technological quality will be improved to the level of wheat.