GROWTH ANALYSIS AND EVOLUTION IN MARIGOLD AND FRENCH MARIGOLD (Tagetes erecta y Tagetes patula)

Abstract

Mexico is considered as a diversity center for major Tagetes (Asteraceae) species. Since prehispanic age Tagetes erecta and Tagetes patula traditionally have been used as ceremonial flowers, in addition today they have promissory uses in sustentable agriculture, food, medicine, industry and ornamental, however domestication knowledge of these species is limited. Domestication of wild plant is able to change the morphology and development of plant species. In this study, growth analysis technique was used contrasting Tagetes erecta and Tagetes patula species, and regarding to their domestication level. Based on the apical and lateral meristems, it was determined that the flower initation (FI) ocurred 56 days after planting; in addition, flower development (FI to blooming) required 84 days in Tagetes erecta and 104 days in Tagetes patula. Tagetes erecta showed a more uniform seed germination, less branching in stems, lower biomass yield per plant, a shorter life cycle, higher values of the root/stem ratio and higher rates of relative growth and net assimilation than Tagetes patula. For this reasons, Tagetes erecta was considered to be in a higher level of domestication than Tagetes patula.