Leaf Rust Resistance Gene Lr9 and Winter Wheat Yield Reduction: I. Yield and Yield Components

Crop Science ◽  
1996 ◽  
Vol 36 (6) ◽  
pp. 1590-1595 ◽  
Author(s):  
Silvano Ortelli ◽  
Hans Winzeler ◽  
Michael Winzeler ◽  
Padruot M. Fried ◽  
Josef Nösberger
Keyword(s):  
Winter Wheat ◽  
Leaf Rust ◽  
Yield Components ◽  
Rust Resistance ◽  
Wheat Yield ◽  
Leaf Rust Resistance ◽  
Yield Reduction ◽  
Leaf Rust Resistance Gene ◽  
Yield And Yield Components ◽  
Winter Wheat Yield

scholarly journals Tagging and Validation of a Major Quantitative Trait Locus for Leaf Rust Resistance and Leaf Tip Necrosis in Winter Wheat Cultivar Forno

2004 ◽  
Vol 94 (10) ◽  
pp. 1036-1041 ◽  
Author(s):  
T. Schnurbusch ◽  
E. Bossolini ◽  
M. Messmer ◽  
B. Keller
Keyword(s):  
Quantitative Trait Locus ◽  
Winter Wheat ◽  
Leaf Rust ◽  
Quantitative Trait ◽  
Rust Resistance ◽  
Leaf Rust Resistance ◽  
Leaf Rust Resistance Gene ◽  
Artificial Chromosomes ◽  
Genetic Interval ◽  
Trait Locus

A major leaf rust (Puccinia triticina) resistance quantitative trait locus (QTL) (QLrP.sfr-7DS) previously has been described on chromosome 7DS in the winter wheat (Triticum aestivum) cv. Forno. It was detected in a population of single-seed descent (SSD) lines derived from the cross Arina × Forno. QLrP.sfr-7DS conferred a durable and slow-rusting resistance phenotype, co-segregated with a QTL for leaf tip necrosis (LTN) and was mapped close to Xgwm295 at a very similar location as the adult plant leaf rust resistance gene Lr34 found in some spring wheat lines. Here, we describe the validation of this QTL by mapping it to the same chromosomal region close to Xgwm295 on chromosome 7DS in a population of SSD lines from the winter wheat × spelt (T. spelta) cross Forno × Oberkulmer. In both populations, the log of the likelihood ratio curves for leaf rust resistance and LTN peaked at identical or very similar locations, indicating that both traits are due to the same gene. We have improved the genetic map in the target region of QLrP.sfr-7DS using microsatellite and expressed sequence tag (EST) markers. Two EST loci (Xsfr.BF473324 and Xsfr.BE493812) define a genetic interval of 7.6 centimorgans containing QLrP.sfr-7DS, a considerably more precise genetic location for this QTL than previously described both in spring and winter wheat. The identified genetic interval is physically located in the distal 39% of chromosome 7DS. Single-marker analysis identified Xsfr.BF473324 and Xgwm1220 as the most informative loci for QLrP.sfr-7DS and QLtn.sfr-7DS. In the rice genome, the two ESTs flanking the QLrP.sfr-7DS/QLtn.sfr-7DS chromosomal segment in wheat are conserved on chromosome 6S in a region colinear with wheat chromosome 7DS. There, they define a physical region of three rice bacterial artificial chromosomes spanning ≈300 kb.

The effect of seeding date, seeding rate and N fertilization on winter wheat yield and yield components in eastern Newfoundland

2000 ◽  
Vol 80 (4) ◽  
pp. 703-711 ◽  
Author(s):  
D. Spaner ◽  
A. G. Todd ◽  
D. B. McKenzie
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Yield Components ◽  
Wheat Yield ◽  
Triticum Aestivum L ◽  
N Fertilization ◽  
Seeding Rate ◽  
Seeding Date ◽  
Yield And Yield Components ◽  
Winter Wheat Yield

Livestock farmers in Newfoundland presently import most of their feed grain, and local self-sufficiency in grain production is a desirable long-term goal. The overall objective of this work was to refine our understanding of winter wheat (Triticum aestivum L.) production in Newfoundland, with the aim of improving present cropping recommendations. We conducted trials near St. John's in 1998 and 1999 to examine the effect of seeding rate and topdress ammonium nitrate (N) fertilization rate on Borden winter wheat yield and yield components. We also conducted four seeding date trials in the same region. Optimum-treatment grain yields in our six trials ranged from 2.76 to 5.39 t ha−1. In years of variable winter kill, increasing seeding rate up to 450 seeds m−2 increased spikes m−2 at harvest, resulting in increased grain yield. Seeding rate, however, was not as important as N fertilization in maximizing grain yield. Increasing topdress fertilization to 60 kg N ha–1 increased spikes m–2 at harvest in years of variable winter kill, resulting in greater grain yield. In years of high winter survival, the main source of higher grain yield levels (through higher N application rates) was not achieved through greater spikes m−2 at harvest, but rather through an increase in kernel weight. Optimum grain yields occurred at seeding rates of 400 ± 50 seeds m−2, and at topdress fertilizer applications up to a rate of at least 30 kg N ha−1. Given the results of our seeding date experiments, in conjunction with previously developed climatic models, we now consider the optimum seeding date for the eastern region of Newfoundland to be August 31. Key words: Yield component analysis, two-dimensional partitioning, Triticum aestivum L., ammonium nitrate

scholarly journals Map-Based Cloning of Leaf Rust Resistance Gene Lr21 From the Large and Polyploid Genome of Bread Wheat

Genetics ◽  
2003 ◽  
Vol 164 (2) ◽  
pp. 655-664 ◽  
Author(s):  
Li Huang ◽  
Steven A Brooks ◽  
Wanlong Li ◽  
John P Fellers ◽  
Harold N Trick ◽  
...  
Keyword(s):  
Amino Acid ◽  
Leaf Rust ◽  
Resistance Gene ◽  
Bread Wheat ◽  
Rust Resistance ◽  
Agronomic Traits ◽  
Leaf Rust Resistance ◽  
Triticum Aestivum L ◽  
Rust Resistance Gene ◽  
Leaf Rust Resistance Gene

Abstract We report the map-based cloning of the leaf rust resistance gene Lr21, previously mapped to a generich region at the distal end of chromosome arm 1DS of bread wheat (Triticum aestivum L.). Molecular cloning of Lr21 was facilitated by diploid/polyploid shuttle mapping strategy. Cloning of Lr21 was confirmed by genetic transformation and by a stably inherited resistance phenotype in transgenic plants. Lr21 spans 4318 bp and encodes a 1080-amino-acid protein containing a conserved nucleotide-binding site (NBS) domain, 13 imperfect leucine-rich repeats (LRRs), and a unique 151-amino-acid sequence missing from known NBS-LRR proteins at the N terminus. Fine-structure genetic analysis at the Lr21 locus detected a noncrossover (recombination without exchange of flanking markers) within a 1415-bp region resulting from either a gene conversion tract of at least 191 bp or a double crossover. The successful map-based cloning approach as demonstrated here now opens the door for cloning of many crop-specific agronomic traits located in the gene-rich regions of bread wheat.

Sign in / Sign up

Export Citation Format

Share Document