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 Jessen, D. L. Articles by Hodges, C. F. Search for Related Content PubMed Articles by Jessen, D. L. Articles by Hodges, C. F. Agricola Articles by Jessen, D. L. Articles by Hodges, C. F.

Growth-Chamber and Field Reaction of Three Smooth Bromegrass Strains to Pyrenophora bromi (Died.) Drechsl¹

Improved screening procedures would aid in selection for resistance to brown leaf spot caused by Pyrenophora bromi (Died.) Drechsl. (Helminthosporium bromi Died.) in smooth bromegrass (Bromus inermis Leyss.). The objectives of this research were to use a growthchamber inoculation procedure to study variation in brown leaf spot reaction among and within three smooth bromegrass strains and to compare the results with field disease ratings. Reaction to brown leaf spot in the growth chamber was determined as the percentage diseased leaf area on the four youngest leaves on one tiller per plant. Average percentage diseased leaf area increased with an increase in leaf age. The wide range of variation in percentage diseased leaf area among plants within the three strains indicates that the growth-chamber inoculation procedure would be useful for screening plants for brown leaf spot resistance. The association between repeated determinations on the same set of plants suggests that preliminary selection of resistant genotypes on the basis of rank performance in a single growth-chamber trial would be reasonably effective. SB-5, a fiveclone synthetic selected for brown leaf spot resistance in the field, was more resistant to infection in the growth chamber and field than SB-C3, the population from which parent clones of SB-5 were selected, and ‘Lincoln’, a susceptible cultivar. SB-C3 and Lincoln were not significantly different in disease reaction in the growth chamber, but SB-C3 was more resistant than Lincoln in the field.

Key Words: Bromus inermis Leyss. • Brown leaf spot • Disease screening

² Former graduate research assistant; professor of agronomy; and professor of horticulture, agronomy, plant pathology, seed, and weed sciences, Iowa State Univ., Ames, IA 50011.

Received for publication August 23, 1982.