RHEOLOGICAL PROPERTIES STABILITY OF BREAD WHEATS THROUGH ENVIROMENTS AS A FUNCTION OF THEIR HIGH MOLECULAR WEIGHT GLUTENINS

Abstract

To determine the allelic combinations of high molecular weight glutenins (HMW-G) and the stability they confer over rheologic properties of the dough in Mexican bread wheats, ten varieties were evaluated. These included ‘Nahuatl F2000’, ‘Pavón F76’, ‘Temporalera M87’, ‘Rebeca F2000’, ‘Tlaxcala F2000’, ‘Gálvez M87’, ‘Zacatecas VT74’, ‘Romoga F96’, ‘Juchi F2000’ and ‘Batán F96’. Genotypes were planted during the 1999 and 2000 SpringSummer cycle at 22 rainfed environments in the states of México, Tlaxcala, Jalisco, Oaxaca, Puebla, Guanajuato, Morelos and Querétaro. A completely randomized blocks design with 2 replications was used. Viscoelastic (rheologic) properties of the dough such as kneading time (min), W-alveogram, P/L alveogram and P/G-alveogram were evaluated. Data were analyzed by estimating stability parameters through four different models. Varieties ‘Náhuatl F2000’, ‘Pavón F76’ and ‘Temporalera M87’ have HMW-G subunits as follows: 2* at Glu-A1 2*, 17+18 at Glu-B1 and 5+10 at Glu-D1 (combination 1); varieties ‘Rebeca F2000’, ‘Tlaxcala F2000’, ‘Gálvez M87’, ‘Zacatecas VT74’ and ‘Romoga F96’ have 1 at Glu-A1, 17+18 at Glu-B1 and y 5+10 at Glu-D1 (combination 2), and varieties Juchi F2000 and Batán F96 have 2* at Glu-A1, 7+9 at Glu-B1 and 5+10 at Glu-D1 (combination 3). Highly significant differences were found for all the evaluated viscoelastic properties for HMW-G combinations. The estimation of dough stability parameters showed that combination 2 was the most stable over rheologic properties; in addition, such a combination was superior in some viscoelatic characteristics as dough strength; therefore, varieties having such combination are highly desirable for the mechanized industry.