Abstract

DIAZ, Antonio; LAYRISSE, Alfredo; LAYA, Damaris  and  TOVAR, Luis. Diversidad morfológica e isoenzimática de 22 progenitores de una población básica indehiscente de ajonjolí. Agronomía Trop. [online]. 2003, vol.53, n.3, pp.275-294. ISSN 0002-192X.

In order to characterize the genetic diversity of the possible 22 progenitors of the sesame indehiscent basic population PUCV4, 14 morphological and 2 isoenzymatic descriptors were studied. The relative frequencies of each category for each descriptor were processed to estimate two diversity indexes, the Shannon and Weaver index (H) and the Eveness index (E). Also, the Nei genetic diversity index was calculated from electrophoretic data. An information index (I) was generated from H to quantify the total variability, inside and among the groups generated by a Neighbor-Joining tree and a principal coordinate analysis. A high genetic diversity was found, expressed as polymorphic descriptors with H and E estimates of 0.71 and 0.54, respectively. The most polymorphic characters were capsule hairiness, stem hairiness, seed color, lower lip color of flower and capsule number per node. Multivariate analysis generated two groups of genotypes (G1 and G2), with five and nine elements, respectively; the rest of the collection was diffused, formed by the most divergent genotypes, designated as GR. Total diversity was partitioned in two main sources: the first one contained within GR, and the second one among G1, G2 and GR. As a conclusion, it may be state that the progenitora show enough variability to generate the basic population PUCV4 with the broad genetic diversity needed to guarantee genetic gains with selection during breeding.

Keywords : Sesamum indicum; indehiscence; morphological diversity; morphology; isozymes.