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ARS Home » Midwest Area » St. Paul, Minnesota » Plant Science Research » Research » Publications at this Location » Publication #393436
Research Project: Genetic Improvement and Cropping Systems of Alfalfa for Livestock Utilization, Environmental Protection and Soil Health

Location: Plant Science Research

Title: Cell wall characteristics related to alfalfa digestibility

Author
item Heuschele, Deborah - Jo
item Xu, Zhanyou
item LAMB, JOANNE - Retired ARS Employee
item JUNG, HANS-JOACHIM - Retired ARS Employee
item Samac, Deborah - Debby

Submitted to: North American Alfalfa Improvement Conference
Publication Type: Abstract Only
Publication Acceptance Date: 6/9/2022
Publication Date: 6/9/2022
Citation: Heuschele, D.J., Xu, Z., Lamb, J.F., Jung, H.G., Samac, D.A. 2022. Cell wall characteristics related to alfalfa digestibility[sbstract]. North American Alfalfa Improvement Conference. June 7-9, 2022. East Lansing, Michigan.

Interpretive Summary:

Technical Abstract: Fiber digestibility of alfalfa for animal nutrition is a complex system encompassing animal, plant, and microbe biological traits. We investigated the relationship between alfalfa cell wall components and in vitro neutral detergent fiber digestibility (IVNDFD) speed (16-hr) and potential (96-hr) by cattle ruminant microbes. A composite alfalfa (Medicago sativa L.) population from seven commercial cultivars underwent two cycles of bidirectional selection for plants with low or high stem 16-h IVNDFD and low or high stem 96-h IVNDFD. The resulting selected populations were then evaluated by near inferred spectrometry for structural cell wall components. Hemi-cellulose components, xylose, and mannose were found to have a greater negative correlation (-0.81 and -0.88, respectively) on the speed of digestion (16-h IVNDFD) than lignin (-0.70). Whereas, for the overall potential of stem digestibility, lignin had the greatest negative correlation (-0.89). Lignin and 96-h IVNDFD had the strongest broad sense heritability across the populations (0.74 and 0.70, respectively). Xylose was observed to have a moderate broad sense heritability (0.58). Pectin components correlated positively with speed of digestion (0.41) but had limited correlation on the overall digestibility potential. As IVNDFD increased with each breeding cycle, it remained stable across environments as did concentrations of total cell wall components, lignin, hemi-cellulose, and pectin. However, the cellulose concentrations were not stable across environments. Cell wall components such as xylose (hemi-cellulose) and pectin could be used as selection traits for increasing IVNDFD by conventional breeding and these components be a way to link in vitro digestibility to plant genes for genomic selection.