Intergeneric somatic hybridization between wheat (cv Jinan 177) protoplasts that have 24 28 chromosomes and Hapnaldi villosa protoplasts con-taining 11 14 chromosomes was carried out by the polyethylene glycol (PEG) method A high frequency of hybrid calli and plants were obtained frpin the fusion products, as revealed by cytological and biochemical techniques and by PCR analysis of 5S rDNA spacer sequences GISH (genomic in situ hvbridization) anal-ysis confirmed the presence of chromosomes frpin both parents in the hybrid clones and the COlBitlon occur-rence of translocations between them The RFLP analysis of the organellar DNA using mitochondrion-and chloroplast-specific probes revealed that mito-chondria frpin both parents existed in the cells of hybrid calli and their recombination. whereas chloro-plasts segregated and recombined randomly The gross momhology of hybrid plants resembled that of wheat, but the gross morphologv of their ovaries and anthers were intermediate between those of the two parents The relationship between hybrid plant regeneration and the balance of genetic materials in hybrid clones is discussed.