[Development of Triticum aestivum-Leymus racemosus translocation lines NAU601 and NAU618 and their test-cross analysis with double ditelosomic]

Abstract

Two Triticum aestivum-Leymus racemosus disomic translocation lines were selected and identified from irradiated progenies of T. aestivum-L. racemosus addition lines Lr. 2 and Lr. 7 by somotic chromosome C-banding and fluorescence in situ hybridization by using L. racemosus genomic DNA as probe. NAU618 (MS142-3), 2n = 44, is a disomic addition translocation line with a pair of translocated chromosome consisting of 5/6 length of L. racemosus chromosome Lr. 7 (including centromere) and 1/3 distal part of wheat chromosome 1A short arm. The alien segment is about 4/5 of the length of translocated chromosome. NAU601 (MS101-4), 2n = 42, is a disomic translocation lines with a pair of translocated chromosome consisting of 4B short arm, interstitial 1/3 part of 4BL and almost Lr. 2S, the alien segment is a half of the long arm of translocated chromosome. The results of test-cross analysis with T. aestivum c. v Chinese Spring double ditelosomic combine meiotic chromosomes C-banding indicated that the translocated chromosomes in these two translocation lines were involved in chromosome 1A and 4B respectively. Their resistance to wheat scab was identified using single floret inoculation in three successive years and showed that the resistance of NAU618(MS142-3) was similar to that of resistant check variety Sumai 3, and NAU601(MS101-4) was lower than Sumai 3 but much higher than susceptible parent Chinese Spring.