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

AFLP MARKERS FOR THE STUDY OF THE ORIGIN AND DIVERSITY AMONG SPECIES AND INTROGRESSED POPULATIONS OF WILD SUNFLOWERS (H. ARGOPHYLLUS AND H. DEBILIS)

VISCHI M., NONINO F., OLIVIERI A.M.

Dipartimento di Produzione Vegetale e Tecnologie Agrarie, Università di Udine, Via delle Scienze 208, 33100 Udine

Massimo.Vischi@dpvta.uniud.it

wild sunflower, AFLP, introgression, interspecific crosses

Sunflower is becoming one of the most important oil plant in the world. Its acreage increases steadily because of the great use of its seed oil rich in unsaturated fatty acid. Sunflower came in the XVI century from North America to Europe where it was domesticated. According to Heiser et al. (1969) there are 49 species belonging to the genus Helianthus and most of those enclosed in the Section Annuui are annual species crossable even in natural conditions once geographic barriers are overcome. The 13 species enclosed into Annuui Section possess 17 chromosome pairs. They are largely studied as genetic resources in several countries in relation to the soil, water and climate adaptation. They can reveal their interest for genes controlling disease resistance as well for male sterility and restorer used for commercial hybrid production. In Africa, Mozambique, along Inhambane seaside, two sunflower species, H. argophyllus and H. debilis both of Texas origin, grow far apart. However in two small areas on sandy soil they grow together and many plants have been recognised as hybrids, sharing morphological traits typical of the two species (Olivieri et al.,1999). In Mozambique H. argophyllus is a tall plant with silver pubescence over leaves, stems and inflorescence. Possibly in that area assume a perennial habitus, while H. debilis is a short plant with small green leaves, presenting a vegetative cycle lasting only few months. Some putative hybrid plants produced seed from which in Udine, we raised fertile plants. Thus we have some evidences that this material could represent a new species. Deeper investigation is required in order to assess the extent of these data and the stability of this behaviour during generations. Here we report some data concerning morphological differences among the two putative parents and the introgressed material. Plant samples were obtained by seed collected in Inhambane. Plants were grown in pots at Udine in the spring 2000, and observations were carried out during the vegetative season. In summer time some inflorescence were developed and seed was produced in each plant sometimes after self-pollination. For each plant we have build up a hybrid index by adding the scores of each morphological trait typical of H. argophyllus and H. debilis. For such values the two pure species were opposite, whereas those obtained in hybrid plants appeared to be intermediate. Moreover genetic variation by DNA markers is studied within and between populations to ascertain their genetic relationship. We are developing AFLP markers using the same initial procedure reported for H. annuus an H. argophyllus by Quagliaro et al. (2001). Up to now we have tested several primer combinations to find the best resolution in polymorphic bands. After restriction, DNA fragment ranged from 35 to 400 bp, with a pick around 100-200 bps. The two best pair combinations showed about 100 bands of which about one third was polymorphic.