Host/nonhost status and genetics of resistance in barley against three pathotypes of Magnaporthe blast fungi

• Published in: Euphytica Vol. 215; no. 7; pp. 1 - 19
• Main Authors: Aghnoum, R., Bvindi, C., Menet, G., D’hoop, B., Maciel, J. L. N., Niks, R. E.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-07-2019; Springer; Springer Nature B.V
• Subjects: Airborne microorganisms; Analysis; Association mapping; Barley; Biomedical and Life Sciences; Biotechnology; Blast; Blast disease; Chromosome 7; Chromosomes; Cultivars; Cultivation; Disease susceptibility; Explosions; Fungi; Gene mapping; Gene pool; Genes; Genetics; Grain; Grain cultivation; GWAS; Inoculation; Life Sciences; Magnaporthe oryzae; Mapping; mlo; Oryza; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Plant Sciences; Plant species; Populations; Powdery mildew; QTL mapping; Quantitative genetics; Quantitative trait loci; Rice; Wheat; Association mapping; Barley; Blast disease; GWAS; QTL mapping
• ISSN: 0014-2336; 1573-5060
• DOI: 10.1007/s10681-019-2436-z

Blast disease, caused by the
Magnaporthe oryzae/grisea
species complex, occurs in a wide range of wild and cultivated gramineous plant species including rice, wheat and barley. We inoculated a collection of cultivated (
Hordeum vulgare
ssp.
vulgare
L.) and wild (ssp.
spontaneum
) barley accessions with
M. oryzae Oryza
pathotype (MoO),
Triticum
pathotype (MoT) and
Pennisetum
pathotype (MsP) to quantify the host status of barley, and to identify sources of blast resistance. Unlike wheat, the barley gene pool is rich with sources of complete and partial resistance against
Magnaporthe
. Cultivated barley appeared a nonhost to MsP, whereas wild barley showed some degree of susceptibility. All 153 tested rice accessions were resistant to the MoT isolate, suggesting that rice is nonhost to this pathotype. Inoculation of L94/Vada and Vada/SusPtrit RIL mapping populations with MoO and/or MoT isolates of
M. oryzae
indicated one large effect QTL, designated as R
moq1
, on the short arm of chromosome 7H against the MoT isolate PY 67.1 in both populations. Resistance in L94 to the MoO isolate was due to a different QTL, located at 5H. An association mapping panel of West European barley cultivars also suggested that most QTLs were pathotype specific. Six blast resistance genes found in the biparental and association mapping studies coincided with map positions of powdery mildew resistance genes viz.
Mlt
,
Mla6
,
Mlg
,
mlo
,
Mlj
, and
Mlhb
genes. Our QTL and association mapping analyses do not support the association of the
mlo
resistance gene with enhanced susceptibility to
M. oryzae
as reported in literature.