Evaluation of the cross-incompatibility of 'peruvianum-complex' lines with Lycopersicon esculentum mill. by the ovule selection method

Abstract

Two cultivated tomatoes as seed parents and 9 lines of 'peruvianum-complex' (2 lines of L. peruvianum var. humifusum, 5 lines of L. peruvianum, and 2 lines of L. chilense) as pollen parents were used for obtaining F1 hybrid and B1F1 backcross generation by using the ovule selection method. In respect to the efficiency of obtaining F1 and B1F1 (which is evaluated by the number of germinated ovules per fruit) (GOF), three correlation coefficients were calculated, between the two cultivated tomatoes, between 1994 and 1995 for B1F1, and between F1 and B1F1. Between the two cultivated tomatoes, a significant, combined correlation coefficient was obtained from the 3 correlation coefficients of F1 in 1992, B1F1, in 1994 and B1F1 in 1995 (r = 0.750**, d.f. 111). Between the two years, a significant, high, and combined correlation coefficient was obtained (r = 0.907 *, d. f. = 3). The correlation coefficients between F1 and B1F1 and a combined correlation coefficient were not significant in either of the two cultivated tomatoes. One of the 9 lines used in the present study showed a different and unusual GOF for F1 and B1F1. After the one line is excluded, the correlation coefficient become significant (r = 0.754 *, d. f. = 5). This analysis of the correlation coefficient indicates that the differences between the lines of 'peruvianum-complex' as regards the cross-incompatibility with a cultivated tomato exist and that the differences are found similarly in both F1 and B1F1. The two lines of L. peruvianum var. humifusum belong to the highest cross-incompatibility group, most of the lines of L. peruvianum belong to the intermediate group, and the two lines of L. chilense belong to the least cross-incompatibility group. The alternative relationship between F1 and B1B1 is evaluated by linear regression : Y (B1F1) = 0.1082X (F1) + 0.3364 for 'Kyoryoku Ogata Toko', Y = 0.1054 X + 0.0366 for 'Early Pink'. From the result, it is shown that B1F1 is not bigger than F1 in terms of GOF.