THINOPYRUM DISTICHUM ADDITION LINES - PRODUCTION, MORPHOLOGICAL AND CYTOLOGICAL CHARACTERIZATION OF 11 DISOMIC ADDITION LINES AND STABLE ADDITION-SUBSTITUTION LINE

Plants of the partial amphiploid Inia 66/Thinopyrum distichum (2n = 70 )//Inia 66 (2n = 56) were used as male parents in crosses with the mon osomic series in the common wheat cultivar Inia 66. The genome and hom oeologous group of the monosomic used in the cross affected the distri bution of chromosome number of the progeny plants in the F-2 and F-4. Meiosis in the pollen mother cells of the B1F7 partial amphiploids was not stable, and not different from that of the B1F1 in which univalen ts and multivalents were observed. Disomic addition lines were selecte d on the basis of morphology and meiotic stability in the F-2, F-4 and F-5. Eleven of the fourteen possible wheat-Th. distichum disomic addi tion lines were identified using chromosome C-band pattern, as well as size and arm ratio, as genetic markers. Addition of T. distichum chro mosome J(dll) produced a phenotype indicating homoeology with wheat gr oup-2 chromosomes. Clear indications of homoeology based on morphologi cal characteristics were not obtained in any of the other addition lin es, probably due to the mixed homoeology of the Th. distichum chromoso mes relative to wheat. The addition lines were all susceptible to leaf rust, unlike the germplasm-line Indis which carries a leaf rust resis tance gene on a translocation segment derived from Th. distichum. Inst ability of meiotic pairing was observed in all addition lines. The sta bility, or not, of progeny chromosome counts did not reflect the level of chromosome pairing instability in the parental plants. SDS-PAGE fo r gliadin-type seed proteins revealed two addition lines which express ed seed storage proteins uncommon to Inia 66 but typical of Th. distic hum.