Proceedings of the XLVII Italian Society of Agricultural Genetics - SIGA Annual Congress

Verona, Italy - 24/27 September, 2003

ISBN 88-900622-4-X

Poster Abstract - 2.24

INHERITANCE OF PARENTAL GENOMES IN PROGENIES OF MALUS SP. FROM SEXUAL AND APOMICTIC GENOTYPES AS ASSESSED BY SSR MARKERS

C. BISOGNIN*, W. JARAUSCH**, E. SEEMÜLLER***, M.S. GRANDO*

*) Laboratorio di genetica molecolare, Istituto Agrario San Michele all’Adige, Trento

**) Centrum Grüne Gentechnik - Neustadt an der Weinstrasse, Germany

***) Biologische Bundesanstalt für Land und Forstwirtschaft – Dossenheim, Germany

apomixis, Malus, apple genome, SSR markers

The ability of flowering plants to propagate by seed is not necessarily linked to sexuality. Some angiosperms belonging to the families of Poaceae, Asteraceae, Rosaceae and Rutaceae commonly reproduce asexually through seed by a process called apomixis. Progenies derived from apomictic parents are genetic copies of the maternal genotype. As apomixis is not obliged into the genus Malus, we planned to carry out controlled crossings between completely no-parthenogenic and highly apomictic apple accessions. Three sexual (M9, P22 and Prima) and five apomictic selection of rootstocks were crossed in different combinations, including some reverse crossings.

More than 1600 seedlings were DNA typed using codominat SSR markers in order to establish their pedigrees and evaluate the possibility to exploit new genetic resources for the breeding of apple rootstocks.

Results showed two main classes of allele combinations in the progenies: one identical to the mother’s genotype and the second having a third allele at each locus segregating from the male parent. Very few hybrids were observed when flowers from apomictic rootstocks were pollinated with M9 variety. The reverse crossings generated a higher percentage of recombinant seedlings together with an unexpected number of self pollination events.