Abstract only

Tolerance to stripe rust caused by (Puccinia striiformis f. sp. tritici) is one of the most important objectives in the region of Central Asia. In this area, wheat stripe rust over the past few years is the major factor that adversely affects wheat yield and quality and causes considerable economic damage; yield losses reached 30-50%. Conventional breeding methods are not always effective, especially for such polygenic traits like non-race-specific disease resistance. Molecular markers accelerated the development of wheat cultivars with superior resistance by rapid identification of related genes and their transfer into cultivars by conventional crossing and progeny analysis using marker assisted selection. The gene Lr34/Yr18, leaf rust resistance gene is known as "slow rusting gene" which provides durable and non-specific APR and located on the short arm of chromosome 7D. In order to identify sources of rust resistance the hybrids populations F4 were studied. As parents, well characterized and possess Lr34/Yr18 cultivars Anza, Opata 85, Super Kauz, Parula and Cook were used. The family of 130-150 F4 lines was phenotyped for adult plant leaf and stripe rust resistance and leaf tip necrosis, Ltn. Molecular survey was conducted to screen the wheat lines of F4 hybrid populations. Lr34/Yr18 genes were detected with a specific STS marker csLV34 linked with these genes. The robustness of the csLV34 marker in postulating the likely occurrence of Lr34/Yr18 across a wide range of germplasm was confirmed (Kolmer et al., 2008). The DNA marker was present in 18 lines of hybrid population F4 Almaly x Super Kauz, 56 lines were found in F4 Parula × 293c, 43 lines of F4 Babax 1 × Opata 85 and 37 lines in population Madsen × Cook and 44 lines in Progress × Anza. The results obtained with this marker were compared with determinations of Lr34/Yr18 by adult plant rust resistance and presence or absence of morphological marker, Ltn. Screening of segregating populations using Ltn marker confirmed data obtained from molecular analysis using csLV34 and allowed selecting the number of lines as potential carriers of Lr34/Yr18 gene. Thus, using complex of morphological Ltn and molecular markers, associated to, 142 carriers of wheat leaf and stripe rust resistance genes were identified. The use of STS marker csLV34 and morphological marker leaf tip necrosis are the reliable approach to identification of carriers for effective slow rusting Lr34/Yr1 gene.

Global Wheat Program

English

Lucia Segura

INT1787

CIMMYT Staff Publications Collection