Analysis of chromosomal and organellar DNA of somatic hybrids between Triticum aestiuvm and Haynaldia villosa Schur

Abstract.

Intergeneric somatic hybridization between wheat (cv. Jinan 177) protoplasts that have 24–28 chromosomes and Haynaldia villosa protoplasts containing 11–14 chromosomes was carried out by the polyethylene glycol (PEG) method. A high frequency of hybrid calli and plants were obtained from the fusion products, as revealed by cytological and biochemical techniques and by PCR analysis of 5S rDNA spacer sequences. GISH (genomic in situ hybridization) analysis confirmed the presence of chromosomes from both parents in the hybrid clones and the common occurrence of translocations between them. The RFLP analysis of the organellar DNA using mitochondrion- and chloroplast-specific probes revealed that mitochondria from both parents existed in the cells of hybrid calli and their recombination, whereas chloroplasts segregated and recombined randomly. The gross morphology of hybrid plants resembled that of wheat, but the gross morphology 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.