scholarly journals INHERITANCE OF ADULT PLANT RESISTANCE TO LEAF RUST IN FIVE EGYPTIAN BREAD WHEAT CULTIVARS

2007 ◽  
Vol 32 (6) ◽  
pp. 4355-4368
Author(s):  
O. Boulot ◽  
A. Gad-Alla
Keyword(s):  
Leaf Rust ◽  
Bread Wheat ◽  
Plant Resistance ◽  
Adult Plant Resistance ◽  
Adult Plant ◽  
Wheat Cultivars

Genetics of adult-plant leaf-rust resistance in four Indian and two Australian bread wheat cultivars

Genome ◽  
1994 ◽  
Vol 37 (3) ◽  
pp. 436-439 ◽  
Author(s):  
F Shiwani ◽  
R. G. Saini
Keyword(s):  
Leaf Rust ◽  
Bread Wheat ◽  
Resistance Genes ◽  
Plant Resistance ◽  
Rust Resistance ◽  
Adult Plant Resistance ◽  
Leaf Rust Resistance ◽  
Adult Plant ◽  
Wheat Cultivars ◽  
Partial Dominance

Genetic studies for leaf-rust resistance were conducted on four Indian (CPAN1235, HD2135, HP1209, and VL404) and two Australian (CSP44 and Oxley) bread wheat cultivars. The F2 and F3 plants from their crosses with each other and with susceptible cultivar Agra Local were tested against a mixture of pathotypes 77-1 and 77-2 (variants of race 77). Disease scores on F1's from resistant/susceptible parent crosses indicated partial dominance of resistance in these wheats. The six cultivars have two adult-plant resistance genes each. Their intercrosses revealed similar resistance gene(s) in CSP44 and Oxley, and CPAN1235 and HP1209. The six wheats appear to carry at least seven diverse leaf-rust resistance genes (temporarily named LrI to LrO) against pathotypes 77-1 + 77-2. Adult-plant resistance is additive and therefore the combinations of partially effective resistance genes identified in this study can provide higher levels of resistance. Because these genes are of hexaploid origin, they can be easily exploited in breeding programs. Furthermore, two or more resistance genes from the six wheat cultivars when combined with Lr34 are likely to impart durable resistance to leaf rust.Key words: adult-plant resistance, leaf-rust resistance, wheat, Puccinia recondita, Triticum aestivum.

scholarly journals Seedling and Adult Plant Resistance to Powdery Mildew in Chinese Bread Wheat Cultivars and Lines

Plant Disease ◽  
2005 ◽  
Vol 89 (5) ◽  
pp. 457-463 ◽  
Author(s):  
Z. L. Wang ◽  
L. H. Li ◽  
Z. H. He ◽  
X. Y. Duan ◽  
Y. L. Zhou ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Bread Wheat ◽  
Resistance Genes ◽  
Plant Resistance ◽  
Adult Plant Resistance ◽  
The United States ◽  
Adult Plant ◽  
Wheat Cultivars ◽  
Seedling Resistance ◽  
Progress Curve

Powdery mildew, caused by Blumeria graminis f. sp. tritici, is a widespread wheat disease in China. Identification of race-specific genes and adult plant resistance (APR) is of major importance in breeding for an efficient genetic control strategy. The objectives of this study were to (i) identify genes that confer seedling resistance to powdery mildew in Chinese bread wheat cultivars and introductions used by breeding programs in China and (ii) evaluate their APR in the field. The results showed that (i) 98 of 192 tested wheat cultivars and lines appear to have one or more resistance genes to powdery mildew; (ii) Pm8 and Pm4b are the most common resistance genes in Chinese wheat cultivars, whereas Pm8 and Pm3d are present most frequently in wheat cultivars introduced from CIMMYT, the United States, and European countries; (iii) genotypes carrying Pm1, Pm3e, Pm5, and Pm7 were susceptible, whereas those carrying Pm12, Pm16, and Pm20 were highly resistant to almost all isolates of B. graminis f. sp. tritici tested; and (iv) 22 genotypes expressed APR. Our data showed that the area under the disease progress curve, maximum disease severity on the penultimate leaf, and the disease index are good indicators of the degree of APR in the field. It may be a good choice to combine major resistance genes and APR genes in wheat breeding to obtain effective resistance to powdery mildew.

Breeding triple rust resistant wheat cultivars for Australia using conventional and marker-assisted selection technologies

2007 ◽  
Vol 58 (6) ◽  
pp. 576 ◽  
Author(s):  
H. S. Bariana ◽  
G. N. Brown ◽  
U. K. Bansal ◽  
H. Miah ◽  
G. E. Standen ◽  
...  
Keyword(s):  
Leaf Rust ◽  
Resistance Genes ◽  
Plant Resistance ◽  
Stem Rust ◽  
Marker Assisted Selection ◽  
Rust Resistance ◽  
Adult Plant Resistance ◽  
Adult Plant ◽  
Wheat Cultivars ◽  
The University

Stem rust susceptibility of European wheats under Australian conditions posed a significant threat to wheat production for the early British settlers in Australia. The famous Australian wheat breeder, William Farrer, tackled the problem of stem rust susceptibility through breeding fast-maturing wheat cultivars. South-eastern Australia suffered a severe stem rust epidemic in 1973, which gave rise to a national approach to breeding for rust resistance. The National Wheat Rust Control Program was set up in 1975, modelled on the University of Sydney’s own rust resistance breeding program, at the University of Sydney Plant Breeding Institute, Castle Hill (now Cobbitty). Back-crossing of a range of sources of resistance provided genetically diverse germplasm for evaluation in various breeding programs. Current efforts are directed to building gene combinations through marker-assisted selection. Major genes for resistance to stem rust and leaf rust are being used in the back-crossing program of the ACRCP to create genetic diversity among Australian germplasm. Stripe rust and to a lesser extent leaf rust resistance in the Australian germplasm is largely based on combinations of adult plant resistance genes and our knowledge of their genomic locations has increased. Additional genes, other than Yr18/Lr34 and Yr29/Lr46, appeared to control adult plant resistance to both leaf rust and stripe rust. Two adult-plant stem rust resistance genes have also been identified. The development of selection technologies to achieve genotype-based selection of resistance gene combinations in the absence of bioassays has evolved in the last 5 years. Robust molecular markers are now available for several commercially important rust resistance genes. Marker-assisted selection for rust resistance is performed routinely in many wheat-breeding programs. Modified pedigree and limited back-cross methods have been used for breeding rust-resistant wheat cultivars in the University of Sydney wheat-breeding program. The single back-cross methodology has proved more successful in producing cultivars with combinations of adult plant resistance genes.

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