Lr34 is a vital gene in developing resistance to leaf rust, stripe rust, and powdery mildew of wheat. Providing simultaneous resistance to various pathogens has made this gene valuable in breeding for wheat resistance...Lr34 is a vital gene in developing resistance to leaf rust, stripe rust, and powdery mildew of wheat. Providing simultaneous resistance to various pathogens has made this gene valuable in breeding for wheat resistance to many diseases. The present study investigates the csLV34 marker’s capability in diagnosing this locus in130 wheat commercial cultivars and advanced wheat lines from Iran, and assesses the impact of this gene on disease severity in field conditions. To assess the reactions of cultivars and lines which contained Lr34 under epidemic conditions of leaf rust, these cultivars were cultivated during the 2009 and 2010 cropping season. Of the 130 studied cultivars, 43 contained Lr34. Cultivars that were selected and studied in stress conditions had the most frequent presence of Lr34. It can be concluded that this gene plays a vital role in increasing the tolerance of cultivars under stress conditions. Lr34 seems to cause active transition of materials out of the cell. In addition to being resistant to several important diseases of wheat, Lr34 can increase tolerance to stresses such as salinity. Considering the calculated value for AUDPC (3%-440%/d) in cultivars containing Lr34, it seems that some cultivars contained additional resistance genes. The rate of infection in all cultivars, when presence of Lr34 was detected through the molecular marker, was lower than in other cultivars. Field results confirmed the results of the analysis using the csLV34b molecular marker.展开更多
Leaf rust caused by Puccinia triticina is an economically-important disease in wheat worldwide.A combination of different types of resistance genes may significantly enhance rust resistance under rust-favorable condit...Leaf rust caused by Puccinia triticina is an economically-important disease in wheat worldwide.A combination of different types of resistance genes may significantly enhance rust resistance under rust-favorable conditions.To investigate the interactions between the rust resistance gene Lr34 and the lesion mimic gene lm on 1BL in Ning 7840,a segregating F8-10 population of 180 recombinant inbred lines was developed from Ning 7840/Chokwang and evaluated for both lesion mimic expression and leaf rust response at the adult plant stage in a greenhouse.A major quantitative trait locus(QTL),derived from Sumai 3,was co-localized with Lr34 on chromosome 7D and explained 41.5% of phenotypic variations for rust severity and 22.1% for leaf tip necrosis(LTN).The presence of Lr34 was confirmed by Lr34-specific markers cssfr1 and cssfr2 in Ning 7840 and Sumai 3.Unlike Lr34,lm conditioned a spontaneous lesion mimic phenotype and had a significant effect on reducing uredinial size,and a smaller effect on severity.Additive effects were observed between lm and Lr34 for severity and LTN,and an epistatic effect was observed for infection type.Single marker analysis also identified several other QTL with minor effects on severity,infection type,or LTN.展开更多
文摘Lr34 is a vital gene in developing resistance to leaf rust, stripe rust, and powdery mildew of wheat. Providing simultaneous resistance to various pathogens has made this gene valuable in breeding for wheat resistance to many diseases. The present study investigates the csLV34 marker’s capability in diagnosing this locus in130 wheat commercial cultivars and advanced wheat lines from Iran, and assesses the impact of this gene on disease severity in field conditions. To assess the reactions of cultivars and lines which contained Lr34 under epidemic conditions of leaf rust, these cultivars were cultivated during the 2009 and 2010 cropping season. Of the 130 studied cultivars, 43 contained Lr34. Cultivars that were selected and studied in stress conditions had the most frequent presence of Lr34. It can be concluded that this gene plays a vital role in increasing the tolerance of cultivars under stress conditions. Lr34 seems to cause active transition of materials out of the cell. In addition to being resistant to several important diseases of wheat, Lr34 can increase tolerance to stresses such as salinity. Considering the calculated value for AUDPC (3%-440%/d) in cultivars containing Lr34, it seems that some cultivars contained additional resistance genes. The rate of infection in all cultivars, when presence of Lr34 was detected through the molecular marker, was lower than in other cultivars. Field results confirmed the results of the analysis using the csLV34b molecular marker.
基金partly funded by the Priority Academic Program Development of Jiangsu Higher Education Institutionthe National Research Initiative of the USDA Cooperative State Research,Education and Extension Service,CAP (2006-55606-16629)the Kan-sas Agricultural Experiment Station,Manhattan,Kansas,USA (10-325-J)
文摘Leaf rust caused by Puccinia triticina is an economically-important disease in wheat worldwide.A combination of different types of resistance genes may significantly enhance rust resistance under rust-favorable conditions.To investigate the interactions between the rust resistance gene Lr34 and the lesion mimic gene lm on 1BL in Ning 7840,a segregating F8-10 population of 180 recombinant inbred lines was developed from Ning 7840/Chokwang and evaluated for both lesion mimic expression and leaf rust response at the adult plant stage in a greenhouse.A major quantitative trait locus(QTL),derived from Sumai 3,was co-localized with Lr34 on chromosome 7D and explained 41.5% of phenotypic variations for rust severity and 22.1% for leaf tip necrosis(LTN).The presence of Lr34 was confirmed by Lr34-specific markers cssfr1 and cssfr2 in Ning 7840 and Sumai 3.Unlike Lr34,lm conditioned a spontaneous lesion mimic phenotype and had a significant effect on reducing uredinial size,and a smaller effect on severity.Additive effects were observed between lm and Lr34 for severity and LTN,and an epistatic effect was observed for infection type.Single marker analysis also identified several other QTL with minor effects on severity,infection type,or LTN.
