scholarly journals Resistance to Grain Mold and Downy Mildew in a Mini-Core Collection of Sorghum Germplasm

Plant Disease ◽  
2010 ◽  
Vol 94 (4) ◽  
pp. 439-444 ◽  
Author(s):  
Rajan Sharma ◽  
V. P. Rao ◽  
H. D. Upadhyaya ◽  
V. Gopal Reddy ◽  
R. P. Thakur
Keyword(s):  
Downy Mildew ◽  
Core Collection ◽  
Resistance Breeding ◽  
Downy Mildew Resistance ◽  
Mildew Resistance ◽  
Mini Core Collection ◽  
Grain Mold ◽  
Mold Resistance ◽  
Photoperiod Sensitive ◽  
Landrace Accessions

Grain mold and downy mildew are important biotic constraints to grain sorghum (Sorghum bicolor) production worldwide and are best managed through host plant resistance. A sorghum mini-core collection composed of 242 germplasm accessions developed from a core collection of 2,246 landrace accessions from 58 countries was evaluated to identify sources of grain mold and downy mildew resistance. Of the 242 accessions, 140 that flowered during the rainy season (the other 102 accessions were photoperiod sensitive) were screened for grain mold resistance in a grain mold nursery under field epiphytotic conditions during 2007 and 2008. All 242 accessions were screened for downy mildew in the greenhouse using a sandwich inoculation technique. Fifty accessions were resistant to grain mold (≤10% mean severity). These resistant accessions represented four basic and six intermediate races of sorghum that originated from 21 countries and exhibited considerable diversity for agronomic and morphological traits. Downy mildew resistance (mean incidence ≤10%) was observed only in six (IS 28747, IS 31714, IS 23992, IS 27697, IS 28449, and IS 30400) of the 242 accessions. One accession, IS 23992, exhibited resistance to both the diseases. The morphologically and agronomically diverse accessions that are resistant to grain mold or downy mildew should be useful to sorghum disease resistance breeding programs.

scholarly journals High resolution mapping and candidate gene identification of downy mildew race 16 resistance in spinach

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Gehendra Bhattarai ◽  
Wei Yang ◽  
Ainong Shi ◽  
Chunda Feng ◽  
Braham Dhillon ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Downy Mildew ◽  
Association Analysis ◽  
Spinacia Oleracea ◽  
Genotyping By Sequencing ◽  
Significant Snps ◽  
Snp Markers ◽  
Resistance Locus ◽  
Downy Mildew Resistance ◽  
Mildew Resistance

Abstract Background Downy mildew, the most devastating disease of spinach (Spinacia oleracea L.), is caused by the oomycete Peronospora effusa [=P. farinosa f. sp. spinaciae]. The P. effusa shows race specificities to the resistant host and comprises 19 reported races and many novel isolates. Sixteen new P. effusa races were identified during the past three decades, and the new pathogen races are continually overcoming the genetic resistances used in commercial cultivars. A spinach breeding population derived from the cross between cultivars Whale and Lazio was inoculated with P. effusa race 16 in an environment-controlled facility; disease response was recorded and genotyped using genotyping by sequencing (GBS). The main objective of this study was to identify resistance-associated single nucleotide polymorphism (SNP) markers from the cultivar Whale against the P. effusa race 16. Results Association analysis conducted using GBS markers identified six significant SNPs (S3_658,306, S3_692697, S3_1050601, S3_1227787, S3_1227802, S3_1231197). The downy mildew resistance locus from cultivar Whale was mapped to a 0.57 Mb region on chromosome 3, including four disease resistance candidate genes (Spo12736, Spo12784, Spo12908, and Spo12821) within 2.69–11.28 Kb of the peak SNP. Conclusions Genomewide association analysis approach was used to map the P. effusa race 16 resistance loci and identify associated SNP markers and the candidate genes. The results from this study could be valuable in understanding the genetic basis of downy mildew resistance, and the SNP marker will be useful in spinach breeding to select resistant lines.

scholarly journals Mutants of downy mildew resistance in Lactuca sativa (lettuce).

Genetics ◽  
1994 ◽  
Vol 137 (3) ◽  
pp. 867-874
Author(s):  
P A Okubara ◽  
P A Anderson ◽  
O E Ochoa ◽  
R W Michelmore
Keyword(s):  
Molecular Marker ◽  
Downy Mildew ◽  
Genomic Dna ◽  
Spontaneous Mutation ◽  
Multigene Families ◽  
Downy Mildew Resistance ◽  
Bremia Lactucae ◽  
Wild Type ◽  
Mildew Resistance ◽  
Recessive Mutations

Abstract As part of our investigation of disease resistance in lettuce, we generated mutants that have lost resistance to Bremia lactucae, the casual fungus of downy mildew. Using a rapid and reliable screen, we identified 16 distinct mutants of Latuca sativa that have lost activity of one of four different downy mildew resistance genes (Dm). In all mutants, only a single Dm specificity was affected. Genetic analysis indicated that the lesions segregated as single, recessive mutations at the Dm loci. Dm3 was inactivated in nine of the mutants. One of five Dm 1 mutants was selected from a population of untreated seeds and therefore carried a spontaneous mutation. All other Dm1, Dm3, Dm5/8 and Dm7 mutants were derived from gamma- or fast neutron-irradiated seed. In two separate Dm 1 mutants and in each of the eight Dm3 mutants analyzed, at least one closely linked molecular marker was absent. Also, high molecular weight genomic DNA fragments that hybridized to a tightly linked molecular marker in wild type were either missing entirely or were truncated in two of the Dm3 mutants, providing additional evidence that deletions had occurred in these mutants. Absence of mutations at loci epistatic to the Dm genes suggested that such loci were either members of multigene families, were critical for plant survival, or encoded components of duplicated pathways for resistance; alternatively, the genes determining downy mildew resistance might be limited to the Dm loci.

GENETIC ANALYSIS OF DOWNY MILDEW RESISTANCE DERIVED FROM MUSCADINIA ROTUNDIFOLIA

2003 ◽  
pp. 451-456 ◽  
Author(s):  
Didier Merdinoglu ◽  
Sabine Wiedeman-Merdinoglu ◽  
Pascale Coste ◽  
Vincent Dumas ◽  
Stephanie Haetty ◽  
...  
Keyword(s):  
Genetic Analysis ◽  
Downy Mildew ◽  
Downy Mildew Resistance ◽  
Mildew Resistance ◽  
Muscadinia Rotundifolia

Marker assisted selection for downy mildew resistance in table grapes Pushpa Deore

2021 ◽  
Vol 78 (3) ◽  
pp. 239-243
Author(s):  
Roshni R. Samarth ◽  
Vidya Mane ◽  
Anuradha Upadhyay ◽  
Indu S. Sawant
Keyword(s):  
Downy Mildew ◽  
Marker Assisted Selection ◽  
Downy Mildew Resistance ◽  
Mildew Resistance ◽  
Table Grapes ◽  
Selection For

scholarly journals Historical Introgression of the Downy Mildew Resistance Gene Rpv12 from the Asian Species Vitis amurensis into Grapevine Varieties

PLoS ONE ◽  
2013 ◽  
Vol 8 (4) ◽  
pp. e61228 ◽  
Author(s):  
Silvia Venuti ◽  
Dario Copetti ◽  
Serena Foria ◽  
Luigi Falginella ◽  
Sarolta Hoffmann ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Resistance Gene ◽  
Vitis Amurensis ◽  
Downy Mildew Resistance ◽  
Mildew Resistance ◽  
Asian Species

scholarly journals Inheritance of True Leaf Stage Downy Mildew Resistance in Broccoli

2001 ◽  
Vol 126 (6) ◽  
pp. 727-729 ◽  
Author(s):  
Min Wang ◽  
Mark W. Farnham ◽  
Claude E. Thomas
Keyword(s):  
Downy Mildew ◽  
Control Method ◽  
Recurrent Parent ◽  
Downy Mildew Resistance ◽  
Resistant Parent ◽  
Dh Population ◽  
Mildew Resistance ◽  
Leaf Stage ◽  
True Leaf ◽  
High Level

Downy mildew, incited by the biotrophic fungal parasite, Peronospora parasitica (Pers. Fr.) Fr., is one of the most destructive diseases of broccoli (Brassica oleracea L., Italica Group) and other related crop species throughout the world. Cultivation of resistant cultivars is the most desirable control method because it provides a practical, long-term, and environmentally benign means of limiting damage from this disease. The commercial hybrid cultivar, Everest, has been shown previously to contain a high level of downy mildew resistance. Doubled-haploid (DH) lines developed from that hybrid were also shown to exhibit a similar, high level of resistance at the three- to four-leaf stage. To determine the mode of inheritance of this true leaf resistance, the resistant DH line was crossed to a susceptible line (derived from `Marathon') to produce an F1 hybrid. Subsequently, F2 and backcross (BC) populations were developed from the hybrid. In addition, a DH population of ≈100 lines was developed from the same F1 used to create the F2 and BC. All populations were evaluated for response to artificial inoculation with P. parasitica at the three- to four-leaf stage. F1 plants were resistant like the resistant parent and F2 populations segregated approximately nine resistant to seven susceptible. Using the resistant parent as recurrent parent, BC populations contained all resistant plants, while the BC to the susceptible parent fit a 1 resistant: 3 susceptible segregation ratio. These results can be explained by a model with two complementary dominant genes. This model was confirmed by the DH population that segregated ≈1:3, resistant to susceptible. Due to the dominant nature of this resistance, controlling genes should be easily incorporated into F1 hybrids and used commercially to prevent downy mildew.

Identification of novel genes for improvement of downy mildew resistance in Zea mays

2019 ◽  
Vol 37 (4) ◽  
pp. 493-502
Author(s):  
Kyeong Do Min ◽  
Hyo Chul Kim ◽  
Kyung-Hee Kim ◽  
Jun-Cheol Moon ◽  
Byung-Moo Lee ◽  
...  
Keyword(s):  
Zea Mays ◽  
Downy Mildew ◽  
Downy Mildew Resistance ◽  
Novel Genes ◽  
Mildew Resistance
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