Premium
Interaction of Two Sugary‐1 Alleles (su1 and su1st) with Sugary‐2 (su2) on Characteristics of Maize Starch
Author(s) -
Campbell Mark R.,
Glover David V.
Publication year - 1996
Publication title -
starch ‐ stärke
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.62
H-Index - 82
eISSN - 1521-379X
pISSN - 0038-9056
DOI - 10.1002/star.19960481102
Subject(s) - allele , starch , locus (genetics) , biology , genetics , food science , gene
Two recessive alleles at the maize ( Zea mays L.) sugary‐1 locus, sugary‐1 reference (su1) and sugary‐1 starchy (su1st), were examined. Kernels homozygous for the su1 allele result in a wrinkled/glassy phenotype while su1st kernels were nearly normal in appearance. Both sugary‐1 alleles, however, result in the wrinkled/glassy phenotype when in a double‐mutant combination with the recessive sugary‐2 (su2) gene. Our objectives were to investigate the interaction between su2 and the two sugary‐1 alleles (su1 and su1st) by examining starch thermal properties by Differential Scanning Calorimetry (DSC) and starch granule size using a laser‐based particle size analyzer. A dosage study was also conducted between su2 and the two sugary‐1 alleles in order to provide additional genetic information regarding these gene interactions. The double‐mutant genotypes su1st su2 and su1 su2 produced starches having low gelatinization enthalpy (ΔH) values (2.2 and 0.8J/g, respectively) compared to normal (12.1J/g), su2 (5.2J/g), su1st (10.9J/g) and su1 (9.2J/g). In contrast to previous studies based on birefringence end‐point temperature (BEPT), our DSC data demonstrated that su2 rather than su1 is epistatic with respect to gelatinization temperature. Dosage studies revealed that gelatinization onset (To), peak (Tp) and ΔH decreased upon increasing doses of the recessive su2 allele. A similar dosage effect for su2 was observed in a su1 and su1st background. A dosage effect was also seen for su1 on the ΔH value when the su2 gene was homozygous. No significant dosage effect occurred with respect to starch granule diameter mean or mode. A trend was observed, however, in which a slight increase in starch granule mean and mode was associated with increasing doses of the su1 allele.