Table 3. Relationship between the Q chromosome and hybrid lethality in crosses between N. tabacum and N. occidentalis.

		No. of hybrids
Cross combination	STS markersa	Total	Viable	Inviable
(Haplo-QבSamsun NN’) ♀×N. occidentalis ♂	+	11	0	11
	−	14	0	14

^a‘+’ indicates that Q-chromosome-specific STS markers were detected and ‘−’ indicates that they were not.