Identificação de cultivares de Gladiolus sp. por meio de marcadores genético-bioquímicos e de RAPD

Abstract

In flower production the certification of genetic purity is fundamental to keep characteristics of one cultivar. For such, there is a need of identification of cultivars using more stable markers. In this work, molecular markers of both biochemical genetic and DNA were evaluated aiming the characterization of eleven cultivars of Gladiolus sp. The research was developed in the Department of Agriculture’s Seed Center Laboratory, at the Federal University of Lavras. For enzyme and DNA extraction, the third definitive leaf was collected from sixteen randomly chosen plants and from five corms of each cultivar. The evaluation of the enzymes was made through gel electrophoresis technique. The gels were revealed to the enzymatic systems α-amylase, alcohol dehydrogenase, esterase, peroxidase, maltase dehydrogenate and catalase. The DNA evaluation was made through RAPD technique (Random Amplified Polymorphic DNA) and the products were separated by electrophoresis in 0.8 agarose gel. Out of the tested enzyme systems, low activity for the peroxidase enzyme was detected in the corms, without any occurrence of polymorphism among the tested cultivars. In leaves, for peroxidase enzyme, six different electrophoresis standards were generated. Concerning the enzyme system malate dehydrogenate in the corm and leaf tissues, five different electrophoresis standards were obtained. For alcohol dehydrogenase, in the corm tissues, all obtained standards were monomorphic, except for one cultivar. For catalase analysis, in leaves, no polymorphism in the standards of the analyzed cultivars was found. By means of α-amilase enzyme, in the corms and of esterase, in leaves, it was possible to distinguish all the cultivars of Gladiolus sp. with relation to the use of RAPD for the characterization of gladiolus cultivars, polymorphism in nine tested primers was found. Through biochemical genetic markers and RAPD technique, it is possible to distinguish the cultivars evaluated in this study. The similarity of the cultivars evaluated by the biochemical genetic markers and by RAPD markers range from 0.32 to 0.69.