Effect of Production Environment on Seed Quality of Normal and High-Oleate Large Seeded Virginia-Type Peanut (Arachis hypogaea L.)

Abstract

ABSTRACT Six Virginia-type peanut (Arachis hypogaea L.) cultivars and their paired backcross-derived high-oleate lines were grown during 2003 and 2004 in North Carolina to compare standard germination (SG), cool germination (CG), and electrical conductivity (EC) of seed. Oleic acid level had no influence on SG but did alter CG and EC compared to the corresponding normal oleate cultivars. Averaged across background genotypes, high-oleate lines had lower seed vigor than their paired lines with normal oleic content. The high-oleate lines of three of the six pairs had lower CG and higher EC. Planting and harvest date affected all the seed quality traits measured. Standard germination of both normal and high-oleate lines was reduced in 2004 when harvest was delayed, but was not affected in 2003. In 2003, CG of the high-oleate lines was lower than that of normal lines in three of the four production environments; EC was higher in the high-oleate lines in all planting date and harvest date combinations. In 2004, there was no difference between the CG of normal and high-oleate lines, but EC was higher in the high-oleate lines for three of the four environments. In the greenhouse, the Virginia-type cultivars NC-V 11 and Gregory, along with their paired backcross-derived high-oleate lines were compared at 22/18 C, 26/22 C and 30/26 C day/night temperature regimes. Seed oleic to linoleic acid (O/L) ratio of normal peanut grown in 30/26 C, 26/22 C, and 22/18 C, measured 1.9, 1.5, and 1.3, respectively. The O/L ratio for their high-oleate pairs decreased from 24.7 when grown in 30/26 C to 15.9 in 26/22 C and to 13.7 in 22/18 C. Temperature did not affect the fatty acid composition of axis total lipid or phospholipid fractions. The high-oleate trait was expressed in the axis lipids. The average O/L ratio of axes from normal peanut was 1.1 while that of high-oleate lines was 4.6. Likewise, axis phospholipids for normal and high-oleate lines were 1.0 and 5.9. A lower production environment temperature decreased the O/L ratio of seed oil of high-oleic peanut lines, and the high-oleate trait expressed in peanut seed storage lipids is also expressed in axis membrane lipids to a lesser degree.