Detection and exploitation of white lupin (<i>Lupinus albus </i>L.) genetic variation for seed γ-conglutin content

Abstract

The seed γ-conglutin protein fraction of white lupin has particular pharmacological interest, but its industrial production is hindered by low content in the seed. This study provides an unprecedented assessment of genotypic and environmental variation for seed content and production of γ-conglutin, exploring also the ability of Near-Infrared Spectroscopy (NIRS) to predict seed γ-conglutin content. Significant (P < 0.01) genetic variation for seed γ-conglutin content emerged among ten genotypes (cultivars or breeding lines) across three environments (range: 1.59-2.02 %) and five genotypes in other two environments (range: 1.47-1.80 %). Genotype variation was found also for seed protein content and γ-conglutin proportion on total protein, the latter trait having higher impact than the former on genotype variation for seed γ-conglutin content. The production of γ-conglutin per unit area was affected also by genotype yielding ability beside genotype seed γ-conglutin content. No genotype × environment interaction was detected for any γ-conglutin trait. NIRS-based prediction based on cross-validations was only moderately accurate for seed γ-conglutin content (R2 = 0.66), while being accurate for seed protein content (R2 = 0.95). In conclusion, breeding for higher seed γ-conglutin content is feasible using data from very few test sites and, to some extent, NIRS-based predictions.