Yazar "HOHN, CHRISTOPHER E." seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • [ X ]
    Öğe
    Characteristics of the root system in the diploid genome donors of hexaploid wheat (Triticum aestivum L.)
    (GENETIC RESOURCES AND CROP EVOLUTION, 2017) BEKTAS, HARUN; HOHN, CHRISTOPHER E.; WAINES, J. GILES
    Wild crop relatives are of considerable interest in plant breeding and significant efforts have been made to transfer their genetic variation into modern crops. Of the three diploid progenitors of bread wheat (Triticum aestivum L.), only Aegilops tauschii Coss. has been explored and exploited and only for some above ground characteristics. The three wild progenitors (Aegilops speltoides Tausch., Triticum urartu Tumanian ex Gandilyan, and Aegilops tauschii) have never been assayed for root traits. Here we report such a root study, and include Triticum monococcum L. subsp. boeoticum (Boiss.) Hayek and T. turgidum L. subsp. dicoccoides (Koern. ex Asch. et Graebn.) Thell. Fifteen accessions were selected from the above wild species and tested in the presence of one bread wheat cultivar Pavon F76. Significant variation was observed between and within the taxa. Of all accessions tested, cv. Pavon F76 had the smallest root system at maturity while A. speltoides had the largest root system. Moreover, Aegilops spp. had larger mean values for root biomass when compared with Triticum spp. These results suggest there is significant unexplored potential for the use of wheat wild relatives in wheat breeding to improve the root system, or to develop synthetic mapping populations to study root traits.
  • [ X ]
    Öğe
    Root and shoot traits of bread wheat (Triticum aestivum L.) landraces and cultivars
    (EUPHYTICA, 2016) BEKTAS, HARUN; HOHN, CHRISTOPHER E.; WAINES, J. GILES
    In order to break the current grain yield barriers, breeders require genetic variation. Breeding for resistance to abiotic stresses may lead to better plant survival and improved grain yield. Exploring landraces may expand the genetic diversity of modern wheats. Five Turkish bread wheat landraces and 14 modern durum and bread wheat cultivars were evaluated for root and shoot biomass as well as grain yield for 2 years in three experiments. Root and shoot traits were measured in plants grown in 1 and 1.5 m PVC tubes in a glasshouse. Significant genotypic differences were found within and between landraces and modern wheats. Shoot biomass, total root biomass, shallow root weight, deep root weight, number of tillers per plant, and plant height were significantly greater in landraces compared to modern wheats. Correlation coefficients were positive between root biomass and shoot biomass (0.78), and number of fertile tillers (0.76). Plant height, shallow and deep root weights, as well as the total root biomass were positively correlated. Semi-dwarf and mid-height cultivars had greater grain yield than tall lines: winter wheats had greater harvest index, whereas intermediate (facultative) wheats had greater shallow root weights and total root biomass. Results highlight the mode of adaptation in landraces to water stress and suggest that landraces may be a valuable resource in breeding for altered root architecture.