Pericarp structure and hullability in sunflower inbred lines and hybrids

Abstract

The breeding of sunflower varieties whose seeds (achenes) can be easily hulled would help to optimise industrial hulling before oil extraction, and thus improve the protein content of sunflower seedmeal. Laboratory hulling tests require samples of about 10 g of seed, and so a search was made for characteristics that would permit indirect selection for improved hullability using smaller numbers of seed. Anatomical characteristics of the pericarps of 12 inbred sunflower lines and 18 hybrids were observed using light microscopy. Significant differences between genotypes in the frequency of parenchyma rays separating sclerenchyma zones, and in the proportion of wide and wedgeshaped sclerenchyma zones were observed. However, the phenotypic correlations between these characteristics and hullability measurements with a laboratory huller were too weak to be usable alone in hullability breeding programmes. Observations of hull structure however will probably serve most usefully to explain certain aspects of variation in hullability. © 1994.