Fifth supplementary list of wheat varieties classified according to their genotype for hybrid necrosis and geographical distribution of Ne-genes

Abstract Hybrid necrosis of wheat is caused by two dominant complementary genes Ne1 and Ne2 present in normal phenotype parents and is regarded as a barrier to gene flow between crop species. However, the necrosis alleles still occur at high frequency in modern wheat varieties. In this study, we constructed two high-density genetic maps of Ne1 and Ne2 in winter wheat. In these cultivars, Ne1 was found to be located in a span interval of 0.50 centimorgan (cM) on chromosome 5BL delimited by markers Nwu_5B_4137 and Nwu_5B_5114, while Ne2 co-segregated with markers Lseq102 and TC67744 on 2BS. Statistical analysis confirmed that the dosage effect of Ne alleles also existed in moderate and severe hybrid necrosis systems, and the symptoms of necrosis can also be affected by the genetic background. Furthermore, we clarified the discrete distribution and proportion of the Ne1 and Ne2 in China’s major wheat regions, and concluded that introduced modern cultivars directly affect the frequencies of necrosis genes in modern Chinese cultivars (lines), especially that of Ne2. Taking investigations in spring wheat together, we proposed that hybrid necrosis alleles could positively affect breeding owing to their linked excellent genes. Additionally, based on the pedigree, we speculated that the Ne1 and Ne2 in winter wheat may directly originate from wild emmer and introduced cultivars or hexaploid triticale, respectively.

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Hybrid necrosis as a problem in handling hexaploid × tetraploid wheat crosses

The Journal of Agricultural Science ◽

10.1017/s0021859600028987 ◽

1980 ◽

Vol 94 (2) ◽

pp. 377-382 ◽

Cited By ~ 6

Author(s):

R. S. Gregory

Keyword(s):

Hexaploid Wheat ◽

Tetraploid Wheat ◽

Wheat Breeding ◽

Small Scale ◽

Hybrid Necrosis ◽

Agronomic Characters ◽

Wheat Varieties ◽

Hybrid Plants ◽

Plant Breeding Institute ◽

Selection For

SummaryA tetraploid wheat breeding programme was initiated at the Plant Breeding Institute in 1970. Hexaploid × tetraploid wheat crosses were expected to contribute to the improvement of the tetraploid wheats but severe hybrid necrosis caused the death of the pentaploid Fxhybrid plants in most crosses. The genotypes of tetraploid wheat selections derived from crosses involving Rampton Rivet, a non-carrier of Neu were determined by test crossing to hexaploid wheat varieties which were known to carry the Neim allele. Similarly, hexaploid wheat selections which did not carry Ne2 were identified from crosses involving Maris Ranger by test crossing to durum selections which carried the Nef allele. By the careful choice of one parent, hexaploid x tetraploid wheat crosses were then made which avoided the hybrid necrosis problem. Segregation of the Ne% gene was as expected but selection for agronomic characters appeared to favour the retention of the dominant allele of the Ne1gene. Nevertheless, test crossing on a relatively small scale still identified many non-carriers.

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Hybride necrosis genes in bread wheat varieties (Triticum aestivum L.) of Ukraine

Faktori eksperimental'noi evolucii organizmiv ◽

10.7124/feeo.v23.988 ◽

2018 ◽

Vol 23 ◽

pp. 46-51

Author(s):

A. V. Galaev ◽

M. V. Galaeva

Keyword(s):

Triticum Aestivum ◽

Bread Wheat ◽

Premature Death ◽

Triticum Aestivum L ◽

Microsatellite Analysis ◽

Hybrid Necrosis ◽

Wheat Varieties ◽

Complementary Genes ◽

The North ◽

Adaptive Value

Hybrid necrosis is the gradual premature death of leaves or plants in certain F1-2hybrids of wheat (Triticum aestivum L.), and it is caused by the interaction of two dominant complementary genes Ne1 and Ne2 located on chromosome arms 5BL and 2BS, respectively. To date, necrotic genotypes in most varieties of Ukrainian breeding have not been identified. Aim. This study was conducted to determine the necrotic genotypes in varieties Ukrainian breeding of different regions. Methods. Microsatellite analysis, PAAgel-electrophoresis. Results. 150 genotypes of bread wheat varieties from Ukrainian breeding were identified by loci Xbarc74-5В and Xbarc55-2В closely linked to hybrid necrosis genes Ne1 and Ne2, respectively. Conclusions. The most common in the South of Ukraine is the genotypes Ne1wNe2w/m and Ne1mNe2w/m were revealed. The most of varieties in the North of Ukraine had the genotypes ne1Ne2ms. These genotypes can have breeding and adaptive value for specific geographical conditions. Keywords: Triticum aestivum L., hybride necrosis genes Ne1 and Ne2, microsatellite analysis.

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