EFFECT OF 2 DIFFERENT LOW-MOLECULAR-WEIGHT GLUTENIN SUBUNITS ON DURUM-WHEAT PASTA QUALITY PARAMETERS

FS-derived F-4 and FS durum wheat families from the cross DT471/DT624, homozygous for either of two low molecular weight glutenin subunits ( LMWGS 2 and LMWGS 2(-)) were used in a study to determine the effect o f these subunits on protein content (PROT), cooked pasta disk viscoela sticity (PDV), cooked gluten viscoelasticity (CGV), sodium dodecyl sul fate sedimentation volume (SV), mixograph mixing development time (MDT ), mixograph peak height (MPH), and mixograph total energy(MTE). These subunits were identified using a monoclonal antibody (MAb45/8) specif ic for the LMWGS 2 allele. Both parents and progeny were homozygous fo r HMWGS 6+8 and gliadin band 45. Families homozygous for LMWGS 2 had h igher PDV (t = 2.4, P< 0.01) and SV values (t = 4.9, P = 0.001) than f amilies homozygous for LMWGS 2(-); CGV differed in one year, and MDT a nd PROT were similar for the two alleles. PDV and SV values were posit ively correlated with each other (r = 0.52, P < 0.001) as well as with PROT values (r = 0.59, P < 0.001, r = 0.46, P < 0.001, respectively). Neither PDV or SV were correlated with MDT, while PDV showed only a l ow correlation with CGV (r = 0.30, P < 0.05). CGV was not correlated w ith MDT nor consistently with SV. The major effect of LMWGS 2 type was on PDV and SV rather than on measures of gluten strength (MDT, CGV). PDV and SV values were not greatly influenced by either MDT or CGV val ues, indicating that the former two are being influenced by additional quality components other than gluten strength. This study showed that LMWGS 2 allele is beneficial to improve pasta cooking quality of futu re cultivars and that selection can be readily accomplished using mono clonal antibody MAb45/8.