RF GENES RESTORE FERTILITY IN WHEAT LINES WITH CYTOPLASMS OF ELYMUS-TRACHYCAULUS AND E-CILIARIS

Alloplasmic euploid wheat lines with the cytoplasm of Elymus trachycaulus (2n = 4x = 28, StStHtHt) and Elymus ciliaris (2n = 4x = 28, ScScYcYc) are male sterile and have reduced vigor. Fertile alloplasmic wheat plants are also recovered, but they always contain complete or partial chromosome additions of 1H(t) or 1S(t) (in E. trachycaulus derived lines) or 1Y(c) (in E. ciliaris derived lines) with specific Elymus gliadin genes (Gli-H(t)1, Gli-S(t)1, Gli- Y(c)1) and fertility restoration (Rf) genes. The Rf genes on lHt, IS', and 1Y(c) were named as Rf-H(t)1, Rf-S(t)1, and Rf-Y(c)1, respectively. In this study, we crossed different disomic addition lines with one another to produce double monosomic additions either in E. trachycaulus or E. ciliaris cytoplasm. The chromosome constitution, transmission, and fertility of the selfed and backcrossed progenies of three double monosomic additions with 21'' + 3BS . 1YcS' + 1HtS . 1HtS' (cytoplasm from E. trachycaulus), 21'' + 3BS . 1YcS' + 1HtS . 1HtS' (cytoplasm from E. ciliaris), and 21'' + 3BS . 1YcS' + 7AL . S-1StS' (cytoplasm from E. ciliaris) were analyzed. The results indicated that (i) Rf-H(t)1 and Rf-S(t)1 on 1 H(t) and 1S(t) restored fertility to wheat with E. ciliaris cytoplasm; (ii) Rf-Y(c)1 on 1Y(c) restored fertility to wheat with E. trachycaulus cytoplasm; (iii) cytoplasms of E. ciliaris and E. trachycaulus are closely related; and (iv) certain E. trachycaulus and E. ciliaris chromosomes show preferential transmission.