Inheritance Of Resistance Of Corn To Downy Mildew Caused By Peronosclerospora Philippinensis (Weston) Shaw

Othello  B. Capuno,; Azucena  L. Carpena,

Inheritance Of Resistance Of Corn To Downy Mildew Caused By Peronosclerospora Philippinensis (Weston) Shaw

Abstract:

Evaluation of 36 entries for downy mildew reaction revealed significant differences due to location and genotype components; genotype-environment interaction was also detected. The interactions of general and specific combining ability components with locations were highly significant. The presence of partial or incomplete dominance governing the resistance of corn to downy mildew was detected using the variance/covariance graphic analysis. Estimation of genetic parameter detected major contribution of additive gene action in downy mildew resistance. The average degree of dominance as measured by (H1/D) was partial. Broad and narrow sense heritability estimates were 45.67 and 39.23%, respectively.

References:

AKSEL, R. and JOHNSON, L.P.V.. 1963. Analysis of diallel cross: A worked example. Adv. Front. Plant Sci. 2: 37-53.
BARREDO, F.C. and EXCONDE, O.R. 1973. Incidence of Philippine downy mildew as affected by inoculum, suscept and environment. Phil. Agric. 57: 232-244.
CARANGAL, V.R., CLAUDIO, M.S. and SUMAYAO, M.R. 1970. Breeding for disease resistance to maize downy mildew caused by Sclerospora philippinensis Weston in the Philippines. Indian Phytopath. 23: 285-306.
COMSTOCK, R.E., ROBINSON, H.F. and HARVEY, P.H. 1949. A breeding proce-dure designed to make maximum use of both general and specific combining ability. Amer. Soc. Agron. 41: 360-367.
EXCONDE, O.R. 1974. Corn in the Philippines: Its production and research activities with emphasis on downy mildew. Symposium on downy mildew of maize. Trop. Agric. Res. Ser. No. 8: 21-30.
EXCONDE, O.R. and MOLINA, A.B. JR. 1978. Note: Ridomil (Ciba-Geigy), a seed-dressing fungicide for the control of Philippine corn downy mildew. Phil. J. Crop Sci. 3:60-63.
GOMEZ, K.A. and GOMES, A.A. 1976. Statistical Procedures for Agricultural Research with Emphasis on Rice. International Rice Research Institute. Los Baños, Laguna. 294 р.
HAYMAN, B.1. 1954. The theory and analysis of dialled crosses. Genetics 39: 789-809.
JOSUE, A.R. and EXCONDE, O.R. 1979. Virulence pattern, aggressiveness and sporulation of Sclerospora philippinensis isolates from Bukidnon on Maize. Phil. Agric. 62:96-105.
MATHER, K. and JINKS, J.L. 1971. Estimation of components of variation. Biometrical Genetics. Cornell Univ. Press, Ithaca, New York. 382 p.
SINGH, D. 1973. Dialled cross analysis for combining ability over different environments. II. Indian J. Genetics 33: 469-481.
TITATARN, S. and EXCONDE, O.R. 1974. Comparative virulence and gross mor-phology of isolates of Sclerospora philippinensis Weston on corn. Phil. Agric. 58:90-104.