Authors:J.L. Zárate-Castrejón, C.L. Aguirre-Mancilla, E. Solís-Moya, J.E. Ruiz-Nieto, J.C. Raya-Pérez, J.G. Ramírez-Pimentel, and V. Montero-Tavera
Yellow rust is a wheat disease caused by Puccinia striiformis, this pathogen causes economic losses in susceptible materials, which represent up to 70% of wheat varieties. Currently, the incorporation of genetic resistance through molecular tools, is a process used in the generation of new varieties resistant to this pathogen. A strategy employed to identify genes involved in the resistance to yellow rust is to screen differential EST obtained by suppressive subtractive hybridization. In this research, cDNA was extracted from healthy and inoculated plants from the resistant line V-26 from INIFAP. A set of 200 differentially expressed EST were cloned and sequenced, and 31 of them were selected for expression profile analysis by RT-PCR; additionally, with the aim of validate RT-PCR results, five genes were selected for RT-qPCR analysis in genotypes inoculated by P. striiformis. The results showed high levels of expression of selected genes in genotypes classified as resistant in the field conditions (21, 143, 230, 242, 261 and 277), while in the susceptible genotype 16, few genes were induced by the rust. Expression profiles confirmed significant differences between resistant and susceptible lines.
Authors:M. Mosaad, A. Morgounov, H. Gomez, M. Jarrah, and S. Rajaram
, A. 2005. Inheritance of yellowrust resistance in winter wheat. In: Morgounov et al. (eds), Increasing Wheat Production in Central Asia through Science and International Cooperation. Proc. 1
Central Asia Wheat Conf., Almaty, Kazakhstan: CIMMYT
Authors:D. Huang, H. Zhang, M. Tar, Y. Zhang, F. Ni, J. Ren, D. Fu, L. Purnhauser, and J. Wu
Stripe or yellow rust (Yr), caused by Puccinia striiformis Westend. (Pst), is one of the most important wheat diseases worldwide. New aggressive Pst races can spread quickly, even between countries and continents. To identify and exploit stripe rust resistance genes, breeders must characterize first the Pst resistance and genotypes of their cultivars. To find new sources of resistances it is important to study how wheat varieties respond to Pst races that predominate in other continents. In this study we evaluated stripe rust resistance in 53 Hungarian winter wheat cultivars in China. Twenty-four cultivars (45.3%) had all stage resistance (ASR) and 1 (1.9%) had adult-plant resistance (APR), based on seedling tests in growth chambers and adult-plant tests in fields. We molecularly genotyped six Yr resistance genes: Yr5, Yr10, Yr15, Yr17, Yr18, and Yr36. Yr18, an APR gene, was present alone in five cultivars, and in ‘GK Kapos’, that also had seedling resistance. The other five Yr genes were absent in all cultivars tested.
Authors:M. Osman, X. He, F. Capettini, J. Helm, and P.K. Singh
Fungal diseases pose a great challenge to Canadian barley production, among which are Fusarium head blight (FHB), yellow rust and scald. An integrated management approach is needed to mitigate these diseases, in which breeding for host resistance is the most effective component. Constant evaluation of advanced breeding lines for their resistance to the diseases is important for making steady progression. The main objective of this study was to screen 1,174 barley accessions, from a collaborative project between the Field Crop Development Center (FCDC), Alberta, Canada, and the International Maize and Wheat Improvement Center (CIMMYT), Mexico for their reactions to the three diseases. For FHB a 1-5 scale was employed to discard the very susceptible material in 2012 and 2013. In 2014, 514 most resistant lines having the score 1 in 2013 were re-evaluated in a replicated experiment. The most promising 166 genotypes were selected and advanced for their last evaluation in 2015 where FHB index was measured. Simultaneously, these 166 genotypes were subjected to two more experiments to test their reactions against stripe rust and scald. Eighteen two-rowed barley genotypes exhibiting broad-spectrum resistance to all of the three evaluated diseases were identified in addition to 40 lines combining FHB resistance with resistance to Mexican isolates and natural fungal population of either of the two foliar diseases and could be utilized in breeding programs aimed at improving resistance to multiple barley leaf and head blight diseases.
Authors:B. Kőszegi, G. Linc, Lajos Juhász, L. Láng, and M. Molnár-Láng
Acta Agronomica Hungarica, 48(3), pp. 227–236 (2000) OCCURRENCE OF THE 1RS/1BL WHEAT–RYE TRANSLOCATION IN HUNGARIAN WHEAT VARIETIES B. K Ő SZEGI, G. LINC, A. JUHÁSZ, L. LÁNG and M. MOLNÁR-LÁNG AGRICULTURAL RESEARCH INSTITUTE OF THE HUNGARIAN ACADEMY OF SCIENCES, MARTONVÁSÁR, HUNGARY Received: August 15, 2000; accepted: October 15, 2000 The translocation which involves the substitution of the short arm of the 1R rye chromosome for the short arm of the 1B wheat chromosome by means of centric fusion has exercised an enormous influence on the world’s wheat breeding. Since the first mention of this translocation in 1937 the incidence of the 1RS/1BL translocation has been reported in connection with several hundred wheat varieties. Varieties carrying the translocation possess a chromosome segment which includes the resistance genes Sr31 (stem rust, Puccinia graminis), Lr26 (leaf rust, P. recondita), Yr9 (yellow rust, P. striiformis), Pm8 (powdery mildew, Erysiphe graminis) and Gb (aphid, Schizaphis graminum). The present paper investigates the occurrence of the 1RS/1BL translocation in wheat varieties bred in Hungary in recent years. It was found that 35 (53%) of the 66 Hungarian-bred wheat varieties registered in Hungary between 1978 and 1999 carried the 1RS/1BL translocation.
Authors:H. Khan, S.C. Bhardwaj, O.P. Gangwar, P. Prasad, P.L. Kashyap, S. Savadi, S. Kumar, and R. Rathore
A set of forty wheat cultivars comprising bread wheat, durum and triticale identified during 2010–2014 were tested for resistance to Indian pathotypes of leaf, stem and yellow rusts at seedling stage under controlled conditions. Eight Lr genes (Lr1, Lr3, Lr10, Lr13, Lr14a, Lr23, Lr24 and Lr26) were characterized based on differential interactions with specific rust races. Genes Lr23, Lr26 and Lr13 conferred leaf rust resistance in most of the accessions. Three Yr genes (YrA, Yr2 and Yr9) were inferred in 40 genotypes, where Yr2 followed by Yr9 were most frequent in conferring stripe rust resistance. Ten Sr genes, namely, Sr2, Sr5, Sr8a, Sr7b, Sr9b, Sr9e, Sr11, Sr13, Sr24 and Sr31, were postulated in these lines with predominance of Sr11, Sr31 and Sr2. These Lr, Sr and Yr genes were observed singly or in combination. Robust DNA markers were used to identify adult plant resistance genes Yr18/Lr34/Sr57, Lr68 and Sr2 and all stage resistance genes Lr24/Sr24, Sr28 and Yr9/Lr26/Sr31. STS marker iag95 showed presence of Yr9 in four additional cultivars which were resistant to one or more rusts. Gene Sr28 was identified in seven durum cultivars with the wPt7004 marker. This is first report of Sr28 being present in many Indian wheat cultivars. CsGs-STS marker identified Lr68 in nine cultivars.