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

Salsomaggiore Terme, Italy - 26/29 September, 2001

ISBN 88-900622-1-5

Poster Abstract

PLANT REGENERATION FROM CALLUS OF THE APOMICTIC GRASS PASPALUM SIMPLEX

MOLINARI L., BUSTI A., PUPILLI F., ARCIONI S.

Istituto di Ricerche sul Miglioramento Genetico delle Piante Foraggere del CNR, Via della Madonna alta 130, 06128 Perugia, Italy

Paspalum simplex is a wild subtropical grass characterised by both sexual and apomictic reproduction. Tetraploid apomictic accessions are sexually compatible with diploid sexual races making this species an interesting model system to study apomixis through map-based strategies. The aim of this research was to develop a protocol for plant regeneration from both sexual and apomictic lines of this species in the perspective of testing the effect of apomixis-related sequences isolated from the apomictic genotypes through transformation. Different explants and concentrations of growth regulators were tested and a rapid and efficient regeneration was obtained. The best explants were hypocotyls dissected from ten-day-old seedlings grown in aseptic conditions and controlled environment. The best culture medium for callus induction was based on MS salts (Murashige and Skoog, 1962) enriched with thiamine-HCl 0.4 mg l^-1, myoinositol 100 mg l^-1, sucrose 30 mg l^-1, solidified with 8 g l^-1 of agar and containing 2 mg l^-1 of 2,4-D and 0.05 mg l^-1 kinetine as growth regulators. Early regenerating structures were observed on callus surface after 6-weeks of culture on callus induction medium. Such structures evolved into well developed shoots after two weeks of culture on the same culture medium as before, replacing the growth regulators with NAA 0.5 mg l^-1, and 6-BAP 2 mg l^-1. The shoots formed well developed root systems after two weeks of incubation on the same medium without growth regulators. No significant differences for regeneration capability were noted between sexual and apomictic genotypes.