Breeding Value Evaluation On Aegilops Variabilis-wheat Derivatives

Aegilops variabilis (2n=4x=28, UUSvSv) is a third genetic resource for wheat genetic improvement, with desirable characters like drought resistance, stripe rust resistance, and insect resistance. In previous studies, Ae.variabilis AS24 was hybridized and then backcrossed by common wheat line 3854. By selfing of these hybrids for several years, we obtained some advanced derivatives of Ae.variabilis-wheat. In the present study, we investigated their cytogenetic character, agronomic trait, stripe rust resistance analysis, and DArT markers, to assess their breeding value. The results were as follows:The root tip’s somatic chromosomes of 17 BC1F8lines had stable 42 chromosomes. They, however, exhibited differences in agronomic traits, including plant height, spike length, spikelet number, heading stage, and thousand seed weight. These data provides the reference for breeding nucleus-cytoplasmic hybrids.AS24, line 1 and line 11 were highly resistant to strip rust, while common wheat parent 3854 and other derivative lines were susceptibility to stripe rust with a different degree. This indicates that the stripe rust resistance gene(s) derived from the nuclear of Ae. variabilis AS24. The two lines highly resistant to strip rust provide new resource for strip rust resistance breeding.By DArT-seq analysis, we found that the two lines highly resistant to strip rust contained segments introduced from AS24 on short arm of 2A chromosome, while other lines with the common wheat 3854 type on this region. We speculate a stripe rust resistance gene locating on the introduced chromosomal segment.