Tetrazolium Staining, Mitochondria, and Barley Quality

Triphenyl tetrazolium chloride (TTC) staining of individual isolated barley aleurone layers wits carried out under aseptic conditions and the amount of formazan generated under a standardized incubation period wits quantified. The nature of the tests minimized or excluded the influences of grain damage, ageing or contaminating microorganisms. Embryos front selected Triumph barley grains, having intensely or poorly staining aleurone layers, were grown on to maturity. Collected grain wits analysed and embryos from the highest-staining progeny from the high-staining aleurone line and the lowest-staining progeny of the low-staining aleurone line were grown on to yield grain of the second selected generations. Aleurone layers of the high-staining line continued to stain intensely, respired strongly, and generated large amounts of alpha-amylase in response to gibberellic acid and embryos from these grains respired and grew vigorously, as did whole grains. In contrast, the aleurone layers of grains from the low-staining line continued to stain poorly and respired weakly, generated little alpha-amylase in response to gibberellic acid, the embryos respired slowly and lacked vigour and, like the whole grains, grew poorly. It is proposed that these results are the consequence of the selection procedure separating lines with superior and interior mitochondria. If this apparently novel approach using TTC staining is confirmed as being valid, it opens a new way for plant breeders to select for more vigorous cereal lines.