HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Kawano, K. Articles by Kano, Y. Search for Related Content PubMed Articles by Kawano, K. Articles by Kano, Y. Agricola Articles by Kawano, K. Articles by Kano, Y.

Field Assessment and Inheritance of Cassava Resistance to Superelongation Disease¹

Effects of superelongation disease, caused by the fungus Elsinoe Brasiliensis Zeigler and Lozano, on cassava (Manihot esculenta Crantz) clones (different genotypes) were studied in fields under high natural disease infection to assess value of genetic resistance and efficiency of field selection. The disease caused 20 to 70% yield reduction on susceptible clones relative to resistant clones depending on planting time and presence of cassava bacterial blight. Susceptible clones could not produce good planting stakes for next plantings. On resistant clones, the disease spread slowly while on susceptible ones it spread rapidly causing abnormal stem elongation and leaf death. Resistance was a quantitative trait controlled largely by additive genetic factors and not negatively correlated with yielding ability per se. Cultivar order of resistance was stable over 8 years of observation. Use of resistant parents in hybridizations combined with simple phenotypic field selection under high natural disease pressure should effectively improve resistance of cassava cultivars.

Key Words: Manihot esculenta Crantz • Elsinoe brasiliensis Zeigler and Lozano • Quantitative traits • Additive genetic factors • Yielding ability • Yield reduction

² Plant breeder, visiting scientist (presently, plant breeder, Tropical Agriculture Research Center, Ministry of Agriculture, Forestry and Fishery, Tsukuba, Ibaraki, Japan) and post-graduate intern (presently, Japan International Cooperation Agency, Shinjuku, Tokyo, Japan), CIAT, respectively.

Received for publication June 10, 1982.