The impact of lignin downregulation on alfalfa yield, chemical composition, and in vitro gas production.

Background: Lignin is a complex, phenolic polymer found in plant cell walls that is essential for mechanical support, water and mineral transport, and defense in vascular plants. Over ten different enzymes play a role in the synthesis of lignin in plants. Suppression of any one enzyme or combinations of these enzymes may change the concentration and composition of lignin in the genetically transformed plants.

Enhancing alfalfa conversion efficiencies for sugar recovery and ethanol production by altering lignin composition.

Alfalfa (Medicago sativa L.) biomass was evaluated for biochemical conversion into ethanol using dilute-acid and ammonia pretreatments. The two alfalfa lines compared were a reduced S-lignin transgenic cultivar generated through down regulation of the caffeic acid O-methyltransferase gene and a wild-type control.

Glandular-haired alfalfa resistance to potato leafhopper (Homoptera: Cicadellidae) and hopperburn: development of resistance indices.

Eight proprietary genotypes of glandular-haired alfalfa, Medicago sativa L., supplied by two different companies, were compared for the degree and types of resistance to the potato leafhopper, Ernpoasca fabae (Harris), and hopperburn. A tube cage no-choice bioassay was developed to test leafhopper mortality, feeding, settling preferences, severity of hopperburn symptoms (in this case, defined as both yellowing and stem growth reduction), and trichome density and type on feeding sites.