Transmission of the rye 2R chromosome in backcrosses of wheat-rye 2R(2D) substitution lines to common wheat varieties

Abstract

Transmission of the rye 2R chromosome in backcrosses of wheat-rye substitution lines 2R(2D)1, 2R(2D)2, and2R(2D)3 (Triticum aestivum L. cv. Saratovskaya 29 / Secale cereale L. cv. Onokhoiskaya, 2n = 42) to common wheat varieties Saratovskaya 29 (S29), Novosibirskaya 67 (N67), and line Lutescens 307/97� 23 (Lut307) has been studied. Rye chromosomes are present in the progeny of hybrids BC1 F 2 2R(2D) 1 × S29, 2R(2D)2 × S29, 2R(2D)3 × S29, 2R(2D)3 × N67 and BC1F1 2R(2D)3 × Lut307, 2R(2D)1 × N67, 2R(2D)1 × Lut307; Lut307 × 2R(2D)1 in the disomic or monosomic states; telocentrics and 2R/2D translocations have been recorded as well. The frequency and mode of 2R chromosome transmission are influenced by the gen� otypes of both the wheat-rye substitution line and the recurrent variety. In the backcrossing to N67, rye chro� mosomes of lines 2R(2D)1 and 2R(2D) 3 replace the 2D chromosome more often than in crosses to Lut307 or S29. Chromosomes with aberrations were found in 26% of the hybrids after the first backcross. In the recip� rocal cross of 2R(2D)1 to Lut307, the 2R chromosome was found only in two plants. Putative mechanisms that are responsible for translocations between homological chromosomes of wheat and rye are considered.