Both genetic and environmental conditions affect wheat grain texture: Consequences for grain fractionation and flour properties.

This review summarizes the results of studies on near-isogenic common wheat lines differing in the Pinb-D1 allele encoding puroindoline B or durum wheat into which both wild-type puroindoline genes were introduced. The material was grown in different environments to evaluate the respective effect of puroindoline genes or of the environmental factors on grain characteristics and milling behavior. Environmental conditions were found to impact grain porosity (=1/vitreousness) and the presence of both wild-type puroindoline genes was found to reduce the vitreousness threshold under 60%. Hardness measurements with single kernel characterization system were found to differ from near-infrared reflectance spectroscopy analysis and were linearly related to vitreousness but differently depending on the puroindoline allele carried. Puroindoline genes were found to play a major role in the grain porosity, breaking energy, size of generated particles and in the concentration of phytic acid and damaged starch into flour whereas vitreousness introduced variations in the ability to break and in the level of damaged starch. Finally, the highest flour yield is obtained from either vitreous common wheat grains carrying the wild-type puroindoline alleles or carrying mutated alleles and displaying low vitreousness. This result was confirmed using common French wheat cultivars whose puroindoline genes were identified. Image 1 • Effect of environmental conditions on grain porosity (vitreousness) are demonstrated. • Pinb-D1 allele appears to affect both porosity and grain hardness. • SKCS or NIRS hardness measurements methods are not equivalent. • Highest total flour yield at milling was obtained for grain SKCS values around 30-60. • Puroindoline genes and grain porosity both affects flour biochemical composition. [ABSTRACT FROM AUTHOR]