Gene Del in L. chmielewskii

Chalukova, M., Vulkova-Atchkova, Z. and Lukarska, E.

In the study of F1, F2 and BC1 hybrids of green fruited wild tomato species with cultivated tomatoes we established that delta-carotene was a characteristic component of pigment spectrum of their fruits (Chalukova and Stoeva, 1988). Those investigations showed also that delta-carotene gene of L. pennellii is allelic to Del gene, established by Tomes (1963) in hybrids of L. hirsutum f. typicum. In the present paper results are presented from the study of allelism between delta-carotene gene from L. chmielewskii (Del^ch^) and Del gene. For this purpose a stabilized delta-carotene line has been used, which was obtained by crossing L. esculentum-cv. Immun x F1 (Immun x L. chmielewskii).

The carotenoids from the ripened fruits of each separate plant have been divided by column chromatography of Al2O3 and their quantity content has been estimated spectrophotometrically. In the test for allelism the plants have been estimated for a presence of carotene by thin layer chromatography (TLC) on plates with silicagel. The plates have been chromatographed in S-chambers using petroleum ether-acetone-ethanol (7:2, 5:0,5) as a solvent.

The data for the pigment composition of the fruits of line Del^ch^ Del^ch^ and its hybrids, presented on Table 1, show that Del^ch^ is a semidominant gene and its expression is strongly suppressed in the presence of gene B. These results are very similar with Tomes's data (1967, 1969) for the action of gene Del. In the test for allelism that has been carried out all studies plants from the Del^+^Del^+^ x F1 (Del^ch^Del^ch^ x DelDel) cross are of delta-carotene type. The absence of recombinants between genes Del and Del^ch^ is an evidence of the allelic relationship between the two genes. This results confirm our opinion that in the genomes of green fruit wild tomato species and the same locus carries the delta-carotene gene. That is why the symbol Del may be assigned for all tomato species.

TABLE 1. Test of Allelism Between Genes Del^ch^ and Del

Literature cited:

Chalukova, M. and P. Stovea 1988 Plant Breeding. 100: 230-234

Tomes, M. 1963 Bot. Gaz. 124: 180-185

Tomes, M. 1967 Genetics. 36: 227-232

Tomes, M. 1969 Genetics. 62: 769-780