About Us | Help Videos | Contact Us | Subscriptions
 

Abstract

 

This article in CS

  1. Vol. 22 No. 6, p. 1155-1159
     
    Received: Oct 19, 1981


 View
 Download
 Alerts
 Permissions
Request Permissions
 Share

doi:10.2135/cropsci1982.0011183X002200060016x

Progress in Selecting for Resistance to Stemphylium botryosum (Cool-Temperature Biotype) in Alfalfa1

  1. D. G. Gilchrist,
  2. L. R. Teuber,
  3. A. N. Martensen and
  4. W. A. Cowling2

Abstract

Abstract

Plants from seven alfalfa, Medicago sativa L., cultivars were inoculated with the cool-temperature biotype of Stemphylium botryosum Wallr. in a controlled environment chamber to identify plants resistant to Stemphylium leafspot. Seedlings were inoculated at the 6 to 8-leaf stage, maintained at 18 to 20 C under constant mist for a 48-hour infection period and scored for disease seven days after inoculation. Resistant plants were intercrossed to form a single population which was subjected to two cycles of phenotypic recurrent selection. Progress after two cycles of selection was evaluated in a greenhouse modified to provide conditions similar to the smaller controlled environment chamber. Relative disease reaction of six test cultivars in the two infection environments was the same (r[4] = 0.978). A proportional bulk population, constructed in proportion to each cultivar's contribution to the first selection cycle, was evaluated as an internal standard to measure progress during selection. Disease resistance increased in each selection cycle compared to the standard proportional bulk population with 10, 59, and 89% resistant plants in the proportional bulk, cycle-1, and cycle-2 populations, respectively.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © .