Identification of a molecular marker linked to an Agropyron elongatum-derived gene Lr19 for leaf rust resistance in wheat     

D. P. Cherukuri    S. K. Gupta    A. Charpe    S. Koul    K. V. Prabhu    R. B. Singh    Q. M. R. Haq  S. V. S. Chauhan  W.E. Weber 《Plant Breeding》2003,122(3):204-208

The leaf rust resistance gene Lr19, transferred from Agropyron elongatum into wheat (Triticum aestivum L.) imparts resistance to all pathotypes of leaf rust (Puccinia recondita f.sp. tritici) in South‐east Asia. A segregating F₂ population from a cross between the leaf rust resistant parent ‘HW 2046’ carrying Lr19 and a susceptible parent ‘Agra Local’ was screened in the phytotron against a virulent pathotype 77‐5 of leaf rust with the objective of identifying the molecular markers linked to Lr19. The gene was first tagged with a randomly amplified polymorphic DNA (RAPD) marker S73₇₂₈. The RAPD marker linked to the gene Lr19 which mapped at 6.4 ± 0.035 cM distance, was converted to a sequence characterized amplified region (SCAR) marker. The SCAR marker (SCS73₇₁₉) was specific to Lr19 and was not amplified in the near‐isogenic lines (NILs) carrying other equally effective alien genes Lr9, Lr28 and Lr32 enabling breeders to pyramid Lr19 with these genes.  相似文献   

Identification and characterization of Pyrenophora species causing leaf spot on oat (Avena sativa) in western China     

Hao Chen  Longhai Xue  James F. White  Malik Kamran  Chunjie Li 《Plant pathology》2022,71(3):566-577

Drechslera leaf spot (DLS) is a serious leaf disease of oats chiefly caused by Pyrenophora chaetomioides in the main oat-producing areas of the world. However, other species of Pyrenophora that may cause DLS have not been investigated in China. From 2018 to 2020, a total of 256 strains of Pyrenophora were isolated from nine oat-producing areas in three provinces in western China. Using a combination of morphological characteristics and phylogenetic analysis of the rDNA internal transcribed spacer (ITS), 28S ribosomal RNA gene (LSU), RNA polymerase second largest subunit region (RPB2), and glyceraldehyde-3-phosphate dehydrogenase region (GAPDH), 66% of the isolates were identified as P. chaetomioides and 34% of isolates belonged to P. avenicola. Pathogenicity tests confirmed that P. avenicola also infected oat and caused DLS, but it was less virulent than P. chaetomioides. From our survey, DLS caused by P. avenicola generally occurred in warm areas at lower altitude and the annual average temperature was above 0°C (Huan and Zhenyuan county in Gansu, Huize county in Yunnan), compared to high-altitude areas (Tianzhu county, Shandan county, Haiyan county). The combination of optimal and maximal temperature indicated that P. avenicola had greater tolerance to high temperature, which was also an important factor for its distribution on oats. Precise identification and understanding of virulence, distribution, and occurrence of these pathogens has significance for control of oat DLS in the future.  相似文献   

Physics. Elemental complexity     

Behnia K 《Science (New York, N.Y.)》2008,321(5888):497-498

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