Inheritance of downy mildew resistance, β-1,3-glucanases and peroxidases in pearl millet [Pennisetum glaucum (L.) R. Br.] crosses

• Published in: Theoretical and applied genetics Vol. 102; no. 8; pp. 1221 - 1226
• Main Authors: SHETTY, H. S, VASANTHI, N. S, SAROSH, B. R, KINI, K. R
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01-06-2001; Berlin
• Subjects: Agronomy. Soil science and plant productions; b-1,3-glucanase; Biological and medical sciences; Classical and quantitative genetics; Classical and quantitative genetics. Population genetics. Molecular genetics; Fundamental and applied biological sciences. Psychology; Generalities. Genetics. Plant material; Genetics and breeding of economic plants; Pennisetum glaucum; peroxidase; Sclerospora graminicola; Monocotyledones; Mycosis; Plant pathogen; Enzyme; Phycomycetes; Pennisetum glaucum; Sclerospora graminicola; Molecular interaction; Cereal crop; Fungus resistance; Fungi; Infection; Peroxidases; Gramineae; Glycosidases; Angiospermae; Hydrolases; Genetics; Defense mechanism; Spermatophyta; Peroxidase; Oxidoreductases; Downy mildew; Thallophyta
• ISSN: 0040-5752; 1432-2242
• DOI: 10.1007/s001220000513

The inheritance of resistance to downy mildew disease and the defense-related enzymes beta -1,3-glucanase and peroxidase was studied in crosses of pearl millet using a generation-mean analysis. The study material comprised six generations (susceptible and resistant parents, F1, F2, BC1 and BC2) in three crosses. Seedlings from these generations were inoculated with the downy mildew pathogen Sclerospora graminicola and disease incidence was recorded. Analysis of constitutive levels of beta -1,3-glucanase and peroxidase in the seedlings of different generations indicated that the resistant populations showed higher enzyme activities, while lower activities of the enzymes were recorded in the susceptible populations. In the generation-mean analysis, the significance of scaling tests revealed the existence of non-allelic interactions in the inheritance of resistance to downy mildew as well as with the enzymes. Among the gene effects, both additive and dominant effects were significant. All the non-allelic interaction effects were significant in the crosses. Studies on the isozyme patterns of the enzymes substantiated the results of the disease-incidence experiments in most of the generations. The results indicated that the inheritance of downy mildew disease resistance and the expression of beta -1,3-glucanase and peroxidase in pearl millet is not only under the control of additive and dominant genes but are also governed by complex non-allelic interactions.