The genetic relationship between the tomato mutants, flacca and lateral suppressor, with reference to abscisic acid accumulation.

Two tomato mutants, Lycopersicon esculentum flacca and lateral suppressor, are assigned to map position 59 of chromosome 7. The tight linkage between these two gene loci was detected as a result of attempts to establish whether they would exhibit phenotypic interaction. The possibility that both mutants result in abnormalities of abscisic acid (ABA) accumulation is considered. ABA analysis supports the suggestion that plants homozygous for flacca have a substantially lower concentration but indicates that lateral suppressor homozygotes do not differ from normal in ABA content. An attempt is made to reconcile the results with those of Tucker (1976, New. Phytol. 77, 561-568) by suggesting that lateral suppressor plants may accumulate high levels of an ABA metabolite which is indistinguishable from ABA using the Commelina epidermal strip bioassay.