Effect of the Waxy Gene on Hydrolysis of Sorghum Starch1
- Douglas Tovar,
- G. H. Liang and
- Bryce A. Cunningham2
Dosage effect on the rate of starch granule hydrolysis by α-amylase was investigated with starch isolated from three sorghum (Sorghum bicalor L. Moench) cultivars. Because the cultivars are not isogenic for all genes other than at the waxy locus, their F1 hybrids, and reciprocals were also compared by both chemical and microscopic observations. Starch from ‘Texioca-63’, a cultivar with waxy endosperm, had the most hydrolysis, as indicated by reducing groups liberated when incubated with α-amylase. In hybrids, starch from endosperm genotypes with two doses of the recessive waxy allele were more readily hydrolyzed than starch from those with one dose. The cultivars with nonwaxy endosperm, ‘Combine Kafir 60’ and ‘PL-I’, differed, and starch from crosses having PL-1 as female parent had the lowest hydrolysis rate, suggesting that factors other than waxy gene also affect digestion of starch by α-amylase. The amount of starch hydrolysis by chemical analysis corresponded with starch granule degradation observed by scanning electron microscope.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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