Alexin™-treated wheat cultivars display more tolerance and antibiosis towards two South African Russian wheat aphid ( Diuraphis noxia ) biotypes

Russian wheat aphid (RWA; Diuraphis noxia Kurdjumov) resistance on the 1D chromosome of wheat has been the subject of intensive research. Conversely, the deployment of the Dn4 derived RWA resistant varieties diminished in recent years due to the overcoming of the resistance it imparts in the United States of America. However, this resistance has not been deployed in South Africa despite reports that Dn4 containing genotypes exhibited varying levels of resistance against the South African RWA biotypes. It is possible that there may be certain genetic differences within breeding lines or cultivars that influence the expression of resistance. The aim of this study was to identify single nucleotide polymorphism (SNP) markers associated with resistance to South African RWA biotypes. A panel of thirty-two wheat lines were phenotyped for RWA resistance using four South African RWA biotypes and a total of 181 samples were genotyped using the Illumina 9K SNP wheat chip. A genome wide association study using 7598 polymorphic SNPs showed that the population was clustered into two distinct subpopulations. Twenty-seven marker trait associations (MTA) were identified with an average linkage disequilibrium of 0.38 at 10 Mbp. Four of these markers were highly significant and three correlated with previously reported quantitative trait loci linked to RWA resistance in wheat. Twenty putative genes were annotated using the IWGSC RefSeq, three of which are linked to plant defence responses. This study identified novel chromosomal regions that contribute to RWA resistance and contributes to unravelling the complex genetics that control RWA resistance in wheat.

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Evaluation of Dryland Wheat Cultivars on the Market in South Africa for Resistance against Four Known Russian Wheat Aphid, <i>Diuraphis noxia</i>, Biotypes in South Africa

Advances in Entomology ◽

10.4236/ae.2019.71001 ◽

2019 ◽

Vol 07 (01) ◽

pp. 1-9

Author(s):

Astrid Jankielsohn

Keyword(s):

South Africa ◽

Russian Wheat Aphid ◽

Diuraphis Noxia ◽

Wheat Cultivars

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Protein Composition of Wheat Apoplastic Fluid and Resistance to the Russian Wheat Aphid

Functional Plant Biology ◽

10.1071/pp9960645 ◽

1996 ◽

Vol 23 (5) ◽

pp. 645 ◽

Cited By ~ 8

Author(s):

AJVD Westhuizen ◽

Z Pretorius

Keyword(s):

Protein Composition ◽

Triticum Aestivum L ◽

Russian Wheat Aphid ◽

Diuraphis Noxia ◽

Wheat Cultivars ◽

Time Saving ◽

Aphid Infestation ◽

Sds Page ◽

Apoplastic Fluid ◽

Related Proteins

The protein composition of intercellular fluids from three different wheat cultivars (Triticum aestivum L. cvv. Tugela DN, Molopo DN and Betta DN) with resistance to the Russian wheat aphid, Diuraphis noxia (Mordvilko) and the corresponding near-isogenic susceptible cultivars (Tugela, Molopo and Betta) were studied under conditions of infestation and non-infestation. The aim was to gain information on the mechanism of resistance and the possible presence of molecular markers of resistance. Aphid infestation induced the accumulation of specific corresponding proteins in the intercellular fluids of resistant cultivars only. The infestation-related proteins were of different molecular mass ranges (28-33; 22-24; 18.5-19.5 and 15.5-17 kDa). Some were serologically related to PR proteins. We suspect that the infestation-related proteins are involved in resistance to the Russian wheat aphid. Although not particularly time saving, the intensified bands of infestation-related proteins on SDS-PAGE gels may be useful for determining resistance.

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