See more from this Session: Evaluation of Agronomic Performance and Quality
Over 2,000 new lines have been developed from Louisiana cultivars and germplasm lines. Crude protein contents as high as 14.51% were found among new entries derived from the cultivar Cocodrie. The highest protein content found among new entries derived from the cultivar Cypress was 14.2%. Typical protein contents in varieties Cocodrie and Cypress are between 7 to 8.5%. Base on its amino acid profiles, the highest amino acid increase in a Cocodrie-derived line HP-1570 was in arginine (48.22%). The lowest increase (17.41%) was in the methionine content. An average increase of 33.21% was observed in the lysine content. Lysine is synthesized through a branch of the Asp family pathway that also leads to the synthesis of two additional essential amino acids, methionine and threonine. HP-1570 showed an increase of 17.41 and 34.50% for methionine and threonine, respectively. The lysine biosynthetic branch is strongly regulated by a feedback inhibition loop in which lysine inhibits the activity of dihydrodipicolinate synthase (DHDPS), the first enzyme specifically committed to lysine biosynthesis.