NON-HOMOEOLOGOUS WHEAT-RYE CHROMOSOMAL TRANSLOCATIONS CONFERRING RESISTANCE TO GREENBUG

C-banding and in situ hybridization were used to determine the chromosomal constitution of the greenbug-resistant germplasm GRS 1204. The results showed that this line had the radiation-induced non-homoeologous wheat-rye translocation chromosomes T2AS-1RS . 1RL and T2AL . 2AS-1RS. C-banding analysis further revealed the presence of a wheat-Agropyron elongatum translocation chromosome T1BL . 1BS-3Ae#1L in line GRS 1204, that was derived from 'Teewon'. The greenbug resistance of line GRS 1204 is similar to that of line GRS 1201 that was earlier shown to have the greenbug resistance gene Gb6 located on the IRS arm of the wheat-rye translocation chromosome T1AL . 1RS. Because Gb6 in line GRS 1204 is present on one of the non-homoeologous translocation chromosomes, agronomically line GRS 1201 should be the better adapted source of Gb6 resistance and be used in cultivar improvement.