Genetic Variation of Root Traits in B, A and D Genome Donors of Bread Wheat.

GENETIC VARIATION OF ROOT TRAITS IN B, A AND D GENOME DONORS OF BREAD WHEAT HARUN BEKTAS1, BAHMAN EHDAIE1 J. GILES WAINES1 1: Department of Botany and Plant Sciences, University of California, Riverside, CA 92521-0124, USA Wild wheat relatives are important sources of genetic variation for many traits, including disease resistance, drought tolerance and other biotic and abiotic stresses. Aegilops tauschii has been used as a parent in the generation of synthetics to widen genetic variation in bread wheat. Many other Aegilops and Triticum spp. have been shown to contain genetically beneficial traits, but genetic variation in roots has been little studied. We screened wild wheat relatives of the B, A and D genomes of bread wheat for root traits such as deep rooting, shallow rooting, total root biomass and root length in glasshouses at the University of California Riverside for 2 years. The plant material was collected in Turkey, Syria and Armenia. After seed germination and vernalization in a cold room, seedlings were planted into 1 meter PVC tubes in sand culture and grown until maturity. Shoots were harvested and roots were carefully washed free of sand. Root and shoot characters were measured and analyzed. Significant differences were found in deep and shallow roots as well as total root biomass among and within species. Aegilops tauschii (DD) and Aegilops speltoides (BB) had significantly larger root systems and higher tiller numbers than cultivated Triticum species. Bread wheat cultivar Pavon76 and wild Triticum monococcum (AMAM) had the least root biomass. These results suggest useful root traits are present in the diploid ancestors and can be transferred to wheat cultivars. Genetically valuable root and shoot traits are conserved in wheat wild relatives in germplasm collections.