Host growth induced by genetic tumour grafts.

Abstract

SPONTANEOUS tumours in Nicotiana were first reported by Kostoff1 and are called genetic tumours2. They arise on certain interspecific tobacco hybrids2, and it has been proposed that certain genes when appropriately combined in a hybrid promote the development of tumours3,4. Though in bacterially induced crown gall tumours the tumour state is transmissible from a tumour cell to a normal cell in the absence of viable bacteria5,6, efforts to demonstrate an ability of genetic tumours to induce tumour development across a graft union have failed2. Attempts to graft Nicotiana glauca×Nicotiana langsdorffi hybrid tumour tissues from sterile culture to non-parental species of Nicotiana were unsuccessful because the grafts died7,8. Here we report the successful grafting of N. glauca×N. langsdorffii amphidiploid (GGLL) tissue from sterile culture on to N. tabacum cv. Wisconsin 38. Within a month of grafting, the graft (GGLL tumour tissue) induced the development of host (N. tabacum) shoots in wound sites and some grafts became chimaeral.