GPC Analysis of Rubber in Guayule and Five Species of Parthenium (Asteraceae)

Abstract

Abstract The genus Parthenium includes one species, guayule (P. argentatum Gray), that produces large amounts of good quality rubber. At present, guayule is the subject of research to determine if it can be developed as an alternative crop for the arid areas of the United States and other countries. Interspecific hybridization between guayule and other species of Parthenium can be accomplished without major difficulties, and there are several desirable agronomic traits that can be transferred from these species to guayule. These other species have not been reported to have large amounts of rubber. Rollins reported that some biotypes of Parthenium incanum H.B.K. contain small amounts of rubber. Taylor and Benedict reported that P. tomentosum D.C. var. stramonium (Greene) Rollins contained 0.02% rubber. Angulo-Sanchez examined 21 guayule plants from native stands near Saltillo and found Mw values varied between 6.10×104, 6.10×105, and 1.13×106; Mn values varies between 6.10×104 and 6.10×105 (Reference 7). These values are comparable to Hevea clones examined by Subramanian. In this study, the molecular weights of guayule and five species of Parthenium are reported, the F1 hybrids between guayule and one of these species, P. alpinum was also examined to determine the size of polymers that characterize this particular hybrid.