A mycoparasite on Sclerospora graminicola

1976 ◽  
Vol 54 (3-4) ◽  
pp. 220-223 ◽  
Author(s):  
N. N. Raghavendra Rao ◽  
M. S. Pavgi
Keyword(s):  
Biological Control ◽  
Downy Mildew ◽  
Pearl Millet ◽  
Crop Plant ◽  
Sclerospora Graminicola ◽  
Pennisetum Typhoides ◽  
Improved Varieties ◽  
Major Disease ◽  
Fusarium Semitectum

Downy mildew or 'green ear' disease of pearl millet (Pennisetum typhoides Stapf and Hubb.) incited by Sclerospora graminicola (Sacc.) Schröter has become a major disease on several improved varieties of the crop plant in India. Fusarium semitectum Berk, and Rav. parasitizes the oospores that develop within the leafy proliferations in the earhead, which consequently makes them unviable. The possibility of using the mycoparasite as a biological control is indicated.

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

Sclerospora graminicola. [Descriptions of Fungi and Bacteria].

1983 ◽  
Author(s):  
S. M. Francis
Keyword(s):  
Pearl Millet ◽  
Geographical Distribution ◽  
Pennisetum Glaucum ◽  
Systemic Disease ◽  
Leaf Tissue ◽  
Seed Transmission ◽  
Distal Portion ◽  
Sclerospora Graminicola ◽  
Complete Replacement ◽  
Pennisetum Typhoides

Abstract A description is provided for Sclerospora graminicola. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: The two hosts on which this pathogen causes diseases of major economic importance are Pennisetum typhoides[Pennisetum glaucum] (syn. P. americanum) and Setaria italica. Also recorded on Echinochloa crusgalli, E. crusgalli var. fumentacea, Eleusine indica, Panicum miliaceum, Pennisetum leonis, Saccharum of ficinarum (by inoculation only), Setaria lutescens, S. magna, S. verticillata, S. viridis and Zea mexicana. The disease is very rare on Zea mays with only two confirmed reports, Melhus & Bliss (1928) in the USA and Kenneth (1966) in Israel. DISEASE: Graminicola downy mildew; green ear of pearl millet (Pennisetum typhoides[Pennisetum glaucum]). A biotrophic plant pathogen which invades and colonizes the growing points of young graminaceous plants causing systemic disease. The first leaf to show symptoms is yellowed in the basal portion with a distinct margin between the basal colonized portion and the non colonized distal portion. Leaves formed later show increasing amounts of disease until the entire leaf shows symptoms. Under suitable conditions sporangia form in great profusion on the under surface of the diseased leaf (and, when conditions are favourable, also on the upper surface) forming a conspicuous and characteristic white 'down'. Occasionally discrete local lesions have been observed on otherwise healthy leaves in highly susceptible cultivars in W. Africa. The most distinctive appearance of the disease on pearl millet is, however, the transformation of the inflorescences to vegetative structures with various leaf-like protrusions which vary greatly in size and number from very few on an almost normal inflorescence to complete replacement of the inflorescence by small leafy shoots. As diseased organs mature they become necrotic and often contain oospores within the tissue. In pearl millet the leaves containing oospores do not shred. The areas containing oospores are a deep chocolate brown and usually appear as long stripes down the leaf. On Setaria the symptoms are similar to those observed on pearl millet except that shredding of the leaf tissue containing oospores occurs. In the phase of the disease described above the height of the infected plants differs little from that of healthy plants. Another and less frequent reaction is that the diseased plants are severely stunted, show a yellow mottle, with non-infected parts becoming a much darker green than in healthy plants; few sporangia are produced and no green ears for the plants generally do not head. This reaction is a characteristic response of certain host genotypes. GEOGRAPHICAL DISTRIBUTION: CMI Map 431, ed. 2, 1979. Note that the pearl millet pathotype has not been reported from the Americas. TRANSMISSION: Initial infection is by oospores which may remain viable for up to 10 years (Nene & Singh, 1976). Later infection comes from sporangia developing on early diseased leaves and spread by wind and rain to newly developed tillers which are produced throughout the growth of the plant (Singh & Williams, 1980). Seed transmission occurs from oospores carried with, and on, seed and there are conflicting reports of transmission from mycelium carried within seed (Williams, 1980).

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.

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 DNA fingerprinting detects genetic variability in the pearl millet downy mildew pathogen (Sclerospora graminicola)

1995 ◽  
Vol 91-91 (6-7) ◽  
pp. 856-861 ◽  
Author(s):  
J. G. Sastry ◽  
W. Ramakrishna ◽  
S. Sivaramakrishnan ◽  
R. P. Thakur ◽  
V. S. Gupta ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Downy Mildew ◽  
Dna Fingerprinting ◽  
Pearl Millet ◽  
Sclerospora Graminicola
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