My Account: Log In | Join | Renew
Search
Author
Title
Vol.
Issue
Year
1st Page

Abstract

 

This article in CS

  1. Vol. 40 No. 3, p. 693-699
     
    Received: May 25, 1999
    Published: May, 2000


    * Corresponding author(s): lambx002@maroon.tc.umn.edu
 View
 Download
 Alerts
 Permissions
 Share

doi:10.2135/cropsci2000.403693x

Increased Herbage Yield in Alfalfa Associated with Selection for Fibrous and Lateral Roots

  1. J.F.S. Lamb *a,
  2. D.A. Samacb,
  3. D.K. Barnesc and
  4. K.I. Henjumd
  1. a USDA-ARS Plant Sci. Res. Unit and Dep. Agronomy and Plant Genetics, 411 Borlaug Hall, Univ. of Minnesota, St. Paul, MN 55108-6026 USA
    b USDA-ARS Plant Sci. Res. Unit and Dep. of Plant Pathology, 495 Borlaug Hall, Univ. of Minnesota, St. Paul, MN, 55108-6030 USA
    c USDA-ARS, St. Paul, MN, retired USA
    d Dep. Agronomy and Plant Genetics, 411 Borlaug Hall, Univ. of Minnesota, St. Paul, MN 55108-6026 USA

Abstract

A positive association between root morphology and herbage yield in alfalfa (Medicago sativa L.) has been reported previously. To further investigate this association, we created populations that differ in root morphology within four unrelated experimental germplasm sources. Two germplasm sources were divergently selected for lateral root number, and two sources underwent divergent selection for fibrous root mass followed by divergent selection for lateral root number. Selected and unselected populations from all germplasm sources were evaluated for herbage yield, root morphology, fall dormancy response, and disease resistance. Herbage yield was evaluated using eight replicates of a randomized complete block design with a split-plot arrangement of fertilizer rates (0 and 200 kg N ha−1) as whole plots and alfalfa populations as subplots. Experiments were established twice at each of two locations in May 1994. Two herbage yield harvests were recorded from one experiment at each location, and plots were dug and evaluated for root traits in fall 1994. Herbage yields were taken from the other experiment at each location twice in 1994 and four times in 1995, and again plots were dug and evaluated for root traits in fall 1995. All populations were evaluated for fall dormancy response in 1994 and disease resistance in 1995 according to standard protocols. Populations selected for more fibrous or lateral roots had greater herbage yield than populations selected for no or few fibrous or lateral roots in all four germplasm sources. No differences in root size or weight, dormancy, or disease resistance were found between fibrous or branch-rooted vs. taprooted populations. Selection for fibrous and lateral roots within these alfalfa germplasms increased herbage yield in the tested environments.

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

Copyright © 2000. Crop Science Society of AmericaCrop Science Society of America