Selekcija i Semenarstvo (Jan 2010)
Phenotypic distances of parental components as a possible indicator of heterosis
Abstract
Although the reveal of heterotic groups in maize significantly increased testing efficiency, field trials are still unreplaceable and most time and fund consumable in the process of the hybrid development. The efficiency of breeding programmes could be significantly increased if the hybrid performance could be predicted prior to the field evaluation. Although different marker techniques have been developed and included into current breeding programmes, the satisfactory results have not been obtained yet. The present study is an attempt to inexpensively and rapidly discover indicators that could even partially facilitate the selection of parental pairs in the process of the hybrid development prior to the field evaluation. The phenotypic description of inbred lines according to the UPOV Descriptor was used for the estimation of the phenotypic distances for which it had been assumed that they could, to a certain degree, be an indicator of heterosis. The phenotypic characterization according to the UPOV Descriptor was done for 28 elite inbreds, that are often used in our commercial breeding programmes, and for 24 inbreds originating from the same source, as well as, for an inbred of the unknown origin and their phenotypic distances were estimated. The cluster analysis resulted in the classification that was in high compliance with known information on the origin. It was empirically concluded that great distances of parent inbreds result in good hybrids. Furthermore, high values among certain inbreds belonging to the same heterotic groups are observed on the morphological distance matrix and crosses among them should indeed be tested in the field prior to making any general conclusion on the reliability of the morphological distance in the prediction of heterosis.
