Istituto Genetica Vegetale Sezione di Perugia

The Director is dott. Sergio Arcioni

IAPTC&B, the International Association for Plant Tissue Culture and Biotechnology

European Union Project CAGED - Compounds and Genes for Enhanced Protein Assimilation and Digestibility of Forage Legumes

The research work carried out at the IRMGPF regards the genetic improvement of forage plants through traditional methods and unconventional technologies, such as "in vitro" culture and selection, somatic hybridization, genetic transformation, RFLP and RAPD.

The research topics are focused on forage yield and quality and in detail, are: manipulation of reproductive system to breed high yielding varieties; modification of the chemical composition of forage; improvement of plant resistances to biotic and abiotic stresses.

The forage yield in alfalfa is strictly dependent upon the heterozygosity level expressed as a percentage of di-tri-and tetra-allelic loci and the presence of useful allelic combinations. One of the ways for doubling in alfalfa the diploid level by maintaining high the heterozygosity level is the use of gametes with the somatic chromosome number. Researches are in progress to understand the cytological mechanisms responsible of the production of unreduced gametes in alfalfa and to verify the possibility to produce tetraploid plants through bilateral sexual polyploidization. In the perspective to synthesize a high yielding alfalfa variety, genotypes are selected, within selected progenies, phenotypically for a high forage production and for a low level of heterozygosity through RFLP analysis.

The selected genotypes will be then intercrossed to restore the heterozygosity.

To improve the forage quality two strategies are pursued: genetic transformation with genes codifying for high quality proteins; modification of tannin synthesis in the edible plant organs in order either to induce tannins, if not present, to obtain bloat-safe forage, or to reduce tannins species where the overproduction prevents the free intake by the animal.

To improve forage protein content genes from maize, codifying for seed storage proteins rich in sulphuramonoacids, have been introduced in Lotus corniculatus, species utilized as model, under costitutive and tissue specific promoters. With the aim to regulate tannin content in the forage, the genes involved in their synthesis should be identified and studied. At this purpose different species of the genus Lotus which are polymorphic for this trait are under examination. Through the genetic transformation of Lotus corniculatus with a maize gene, which regulate the antocyanin synthesis, mutants were obtained showing a reduced or even zero content of tannins in the leaves.

Somatic hybridization through protoplast fusion could be utilized to overcome the sexual barriers and to introduce agronomical useful traits, such as adaptation potential and resistance to stresses, whose genetic control either is too complex or unknown. Two species have been combined in fusion experiments with M. sativa: M. coerulea and M. arborea. Analysis of field performance of somatic hybrids are in progress with the perspective of utilizing these plants as starting material for breeding alfalfa varieties of superior agronomical value.