scholarly journals Inheritance and Allelic Relationship Among Downy Mildew Resistance Genes in Pearl Millet

Plant Disease ◽  
2018 ◽  
Vol 102 (6) ◽  
pp. 1136-1140 ◽  
Author(s):  
Chandramani Raj ◽  
Rajan Sharma ◽  
B. Pushpavathi ◽  
S. K. Gupta ◽  
K. Radhika
Keyword(s):  
Downy Mildew ◽  
Pearl Millet ◽  
Dominant Gene ◽  
Single Dominant Gene ◽  
Susceptible Parent ◽  
Sclerospora Graminicola ◽  
Resistant Parent ◽  
Disease Reaction ◽  
Allelic Relationship ◽  
Dominant Genes

Pearl millet downy mildew (DM), caused by Sclerospora graminicola, is of serious economic concern to pearl millet farmers in the major crop-growing areas of the world. To study the inheritance and allelic relationship among genes governing resistance to this disease, three DM-resistant pearl millet lines (834B, IP 18294-P1, and IP 18298-P1) and one susceptible line (81B) were selected on the basis of disease reaction under greenhouse conditions against two isolates of S. graminicola (Sg 526-1 and Sg 542-1). Three resistant parents were crossed with the susceptible parent to generate F1, F2, and backcross BC1P1 (susceptible parent × F1) and BC1P2 (resistant parent × F1) generations for inheritance study. To carry out a test for allelism, the three resistant parents were crossed with each other to generate F1 and F2 generations. The different generations of these crosses were screened for disease reaction against two isolates (Sg 526-1 and Sg 542-1) by artificial inoculation under greenhouse conditions. The segregation pattern of resistance in the F2 and corresponding backcross generations revealed that resistance to DM is controlled by a single dominant gene in 834B and IP 18294-P1 and by two dominant genes in IP 18298-P1. A test for allelism inferred that a single dominant gene for resistance in 834B is nonallelic to that which governs resistance in IP 18294-1, whereas one of the two dominant genes for DM resistance in IP 18298-P1 against the test isolates is allelic to the gene for DM resistance in 834B and a second gene is allelic to the resistance gene present in IP 18294-P1.

scholarly journals Inheritance of Complete Resistance to Pearl Millet Downy Mildew

Plant Disease ◽  
1998 ◽  
Vol 82 (7) ◽  
pp. 791-793 ◽  
Author(s):  
S. D. Singh ◽  
B. S. Talukdar
Keyword(s):  
Downy Mildew ◽  
Pearl Millet ◽  
Pennisetum Glaucum ◽  
Dominant Gene ◽  
Single Plant ◽  
Plant Selection ◽  
Sclerospora Graminicola ◽  
Simple Mode ◽  
Complete Resistance ◽  
Single Plant Selection

Inheritance of downy mildew (Sclerospora graminicola) resistance in pearl millet (Pennisetum glaucum) was studied in a cross involving DMRP (downy mildew resistant Pennisetum) 292 and DMSP (downy mildew susceptible Pennisetum) 23. DMRP 292, derived from IP 18292, and DMSP 23, derived from Tift 23DB, were made homozygous for downy mildew resistance-susceptibility by three generations of single plant selection followinginoculations with homogenized sporangial population of S. graminicola from the ICRISAT Asia Center. Potted seedlings of parental lines, F1, F2, and BC progenies were evaluated for their reactions to downy mildew following inoculation. The results show that complete resistance to downy mildew in DMRP 292 is controlled by a single dominant gene. Because of the simple mode of inheritance, resistance utilization from DMRP 292 is simple and straightforward. We designate this gene as Rsg1.

scholarly journals Transfer of Downy Mildew Resistance from Wild Basil (Ocimum americanum) to Sweet Basil (O. basilicum)

2018 ◽  
Vol 108 (1) ◽  
pp. 114-123 ◽  
Author(s):  
Yariv Ben-Naim ◽  
Lidan Falach ◽  
Yigal Cohen
Keyword(s):  
Downy Mildew ◽  
Dominant Gene ◽  
Susceptible Parent ◽  
Backcross Generation ◽  
Sweet Basil ◽  
Resistant Varieties ◽  
Homeologous Chromosomes ◽  
Tetraploid Parent ◽  
Dominant Genes

Sweet basil (Ocimum basilicum) is susceptible to downy mildew caused by the oomycete foliar pathogen Peronospora belbahrii. No resistant varieties of sweet basil are commercially available. Here, we report on the transfer of resistance gene Pb1 from the highly resistant tetraploid wild basil O. americanum var. americanum (PI 500945, 2n = 4x = 48) to the tetraploid susceptible O. basilicum ‘Sweet basil’ (2n = 4x = 48). F1 progeny plants derived from the interspecific hybridization PI 500945 × Sweet basil were resistant, indicating that the gene controlling resistance (Pb1) is dominant, but sterile due to the genetic distance between the parents. Despite their sterility, F1 plants were pollinated with the susceptible parent and 115 first backcross generation to the susceptible parent (BCs1) embryos were rescued in vitro. The emerging BCs1 plants segregated, upon inoculation, 5:1 resistant/susceptible, suggesting that resistance in F1 was controlled by a pair of dominant genes (Pb1A and Pb1A’). Thirty-one partially fertile BCs1 plants were self-pollinated to obtain BCs1-F2 or were backcrossed to Sweet basil to obtain the second backcross generation to the susceptible parent (BCs2). In total, 1 BCs1-F2 and 22 BCs2 progenies were obtained. The BCs1-F2 progeny segregated 35:1 resistant/susceptible, as expected from a tetraploid parent with two dominant resistant genes. The 22 BCs2 progenies segregated 1:1 resistant/susceptible (for a BCs1 parent that carried one dominant gene for resistance) or 5:1 (for a BCs1 parent that carried two dominant genes for resistance) at a ratio of 4:1. The data suggest that a pair of dominant genes (Pb1A and Pb1A’) residing on a two homeologous chromosomes is responsible for resistance of PI 500945 against P. belbahrii.

scholarly journals Inheritance of Resistance to Blackeye Cowpea Mosaic Virus in White Acre-BVR' Cowpea

HortScience ◽  
1991 ◽  
Vol 26 (2) ◽  
pp. 194-196 ◽  
Author(s):  
Sohedjie Ouattara ◽  
Oyette L. Chambliss
Keyword(s):  
Mosaic Virus ◽  
Dominant Gene ◽  
Enzyme Linked Immunosorbent Assay ◽  
Symptom Expression ◽  
Inheritance Of Resistance ◽  
Cowpea Mosaic Virus ◽  
Single Dominant Gene ◽  
Susceptible Parent ◽  
Resistant Parent ◽  
Blackeye Cowpea Mosaic Virus

Reciprocal crosses were made between `White Acre-BVR', resistant to blackeye cowpea mosaic virus (BICMV), and the susceptible `California Blackeye No. 5' cowpea [Vigna unguiculata (L.) Walp.]. Seedlings from `California Blackeye No. 5', `White Acre-BVR', F1, F2, and backcrosses were mechanically inoculated with BICMV, and evaluated 4 weeks later for symptom expression in the greenhouse. Plants were assayed by enzyme-linked immunosorbent assay. The resistance observed in the F1 and progeny from the backcross to the resistant parent indicated that resistance to BICMV in `White Acre-BVR' was dominant. Furthermore, a 1 resistant: 1 susceptible segregation of progeny from the backcross to the susceptible parent and a 3 resistant: 1 susceptible segregation of the F2 progenies suggested that the resistance to BICMV in `White Acre-BVR' was conferred by a single dominant gene.

INHERITANCE OF CROWN RUST RESISTANCE IN THREE ACCESSIONS OF AVENA STERILIS

1980 ◽  
Vol 22 (1) ◽  
pp. 27-33 ◽  
Author(s):  
D. E. Harder ◽  
R. I. H. McKenzie ◽  
J. W. Martens
Keyword(s):  
Rust Resistance ◽  
Dominant Gene ◽  
Crown Rust ◽  
Inheritance Of Resistance ◽  
Single Dominant Gene ◽  
Avena Sterilis ◽  
Oat Crown Rust ◽  
Crown Rust Resistance ◽  
Resistance Spectrum ◽  
Dominant Genes

The inheritance of resistance to oat crown rust was studied in three accessions of Avena sterilis L. Accession CAV 4274 originated from Morocco, CAV 4540 from Algeria, and CAV 3695 from Tunisia. Seedling rust tests on F2 backcross families indicated the presence of two dominant genes for crown rust resistance in CAV 4274. One of these, a gene conditioning resistance to most races tested, was linked or allelic to gene Pc-38, and was designated gene Pc-62. The second gene conferred resistance only to one of the six races studied, and was not tested further. In CAV 4540, a single dominant gene, Pc-63 was possibly allelic with Pc-62 and linked or allelic to Pc-38. Genes Pc-62 and 63 are generally similar to Pc-38 in their resistance spectrum, but these three genes are differentiated by races CR 102, CR 103, and CR 107. A single dominant gene in CAV 3695 appeared to be Pc-50.

scholarly journals Draft genome sequence of Sclerospora graminicola , the pearl millet downy mildew pathogen

2017 ◽  
Vol 16 ◽  
pp. 18-20 ◽  
Author(s):  
S. Chandra Nayaka ◽  
H. Shekar Shetty ◽  
C.Tara Satyavathi ◽  
Rattan S. Yadav ◽  
P.B.Kavi Kishor ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Pearl Millet ◽  
Genome Sequence ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
Sclerospora Graminicola

Bioagent and chemicals seed dressing for management of Pearl millet downy mildew incited by Sclerospora graminicola

2021 ◽  
Vol 29 (2) ◽  
pp. 110-113
Author(s):  
Sapna Jaiswal ◽  
Rajni S. Sasode ◽  
R.K. Pandya ◽  
Pramod Kumar Gupta
Keyword(s):  
Downy Mildew ◽  
Pearl Millet ◽  
Sclerospora Graminicola ◽  
Seed Dressing

THE INHERITANCE OF LOOSE SMUT RESISTANCE.: I. THE INHERITANCE OF RESISTANCE IN FOUR BARLEY VARIETIES IMMUNE TO RACE 2 OF LOOSE SMUT

1962 ◽  
Vol 42 (1) ◽  
pp. 69-77 ◽  
Author(s):  
E. N. Larter ◽  
H. Enns
Keyword(s):  
Disease Resistance ◽  
Dominant Gene ◽  
The Other ◽  
Inheritance Of Resistance ◽  
Single Dominant Gene ◽  
Loose Smut ◽  
Race 2 ◽  
Or Genes ◽  
Dominant Genes

Four barley varieties, each immune to a Valki-attacking culture of loose smut (designated as race 2), were studied with respect to the inheritance of their resistance. Jet (C.I. 967) and Nigrinudum (C.I. 2222) were each found to possess two independent dominant genes determining resistance. Steudelli (C.I. 2266) proved to be immune to race 2 through the action of a single dominant gene, while resistance of Hillsa (C.I. 1604) was found to be conditioned by two complementary dominant genes. The absence of susceptible F3 families in crosses between Jet, Nigrinudum, and Steudelli indicated that these three varieties have in common a gene or genes for resistance to the race of smut used. The two complementary genes for resistance in Hillsa proved to be distinct from those of the other three varieties under study.The use of genetic analyses of disease resistance based upon classification of F3 families of the backcross to the resistant source is described and the merits of such a method are discussed.

Resistance to downy mildew in pearl millet is associated with increased phenylalanine ammonia lyase activity

2005 ◽  
Vol 32 (3) ◽  
pp. 267 ◽  
Author(s):  
N. P. Geetha ◽  
K. N. Amruthesh ◽  
R. G. Sharathchandra ◽  
H. S. Shetty
Keyword(s):  
Enzyme Activity ◽  
Downy Mildew ◽  
Pearl Millet ◽  
Phenylalanine Ammonia Lyase ◽  
Cultured Cells ◽  
Enzyme Activation ◽  
Sclerospora Graminicola ◽  
Pathogen Infection ◽  
Pal Activity ◽  
Downy Mildew Disease

Phenylalanine ammonia lyase (PAL) activity was studied in pearl millet cultivars with different levels of resistance to the downy mildew disease caused by Sclerospora graminicola, an important oomycete pathogen. PAL activity was elevated in resistant host cultivar and decreased in susceptible cultivars following downy mildew pathogen infection. The enzyme activation varied between cultivars and was correlated with the degree of resistance to downy mildew disease. The induction of PAL as a response to pathogen inoculation was further corroborated by a time-course study in seedlings and cultured cells of pearl millet. The level of PAL activity was highest at 1.5 h in cultured cells and 4 h in seedlings of resistant host cultivar after inoculation with Sclerospora graminicola. Further studies on PAL activity in different tissues of seedlings showed highest enzyme activity in the young growing region of the root of the resistant host cultivars. The accumulation of wall-bound phenolics and lignin was higher in the resistant cultivar seedlings as evidenced by phloroglucinol–HCl staining and p-coumaric acid assay. The temporal changes in lignin concentration and the concentration of soluble phenolics were greater in root tissues of resistant cultivars than in those of susceptible cultivars. Treatment of resistant seedlings with a PAL inhibitor, α-aminooxy-β-phenylpropionic acid, resulted in the enhancement of the enzyme activity, whereas in the presence of 1 mm trans-cinnamic acid the pathogen-induced PAL was completely inhibited. Treatment of pearl millet seedlings with exogenously applied PAL inhibitors induced downy mildew disease susceptibility in the resistant pearl millet cultivar, consistent with direct involvement of PAL in downy mildew resistance. Results are discussed with respect to the presumed importance of host phenolic compounds and lignin accumulation and its relation to PAL activation as a response to the pathogen infection.

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