Abstract

GONZALEZ, Laura; HERNANDEZ, Alexander  and  ALEZONES, Jesús. Molecular characterization of tropical maize (Zea mays L.) lines and its relation to heterotic patterns. Bioagro [online]. 2009, vol.21, n.3, pp.165-172. ISSN 1316-3361.

The germplasma diversity is important for the breeding programs. Thirty five lines of white corn, belonging to DANAC Foundation and three tester lines (CML-144, CML-254, and L20-2#1) of the tropical heterotic pattern ETO x Tuxpeño were evaluated. Thirteen SSR primer pairs distributed in ten chromosomes were used. The amplification of products allowed the construction of a data matrix of information to determine the genetic distance (GD=1-SG) using the Jaccard's coefficient of genetics similarity (GS), to fulfill a dendrogram under the criterion of unweighted pair-group method with arithmetical averages (UPGMA) and perform a principal components analysis (PCA). The heterosis (h=S_AB-0.5 (L_A+L_B)) was determined using yield information of the lines and hybrids. The polymorphic SSR amplified 25 bands in the lines, with an average of 2.08 alleles per SSR and a range from 2 to 3. The lines were located in three groups: Group A represented by the tester L20-2#1 together with CML-254, Group B represented by CML-144, and a third group that did not group with any of the former two. A correlation analysis  was  performed  between  the  estimated  GD´s  and  the  yield, or the heterosis, and significant correlation was obtained by the latter (r = 0.09 ns vs.  r = 0.36 **, respectively). When the distance was correlated between the lines of the opposite group and the tester separately, significant and high values were found only in the comparison CML-144 versus the lines grouped as A with r = 0.55**.

Keywords : Genetics; heterosis; molecular marker; genetic distance; corn.