FURTHER STUDIES ON THE PRIMARY TRISOMICS OF THE TOMATO

Publisher Website
Google Scholar
Abstract
Results of continued research on the primary trisomics of the tomato, carried out for the purpose of completing their identification with the pachytene chromosomes and linkage groups, are reported. All of the trisomics were re-examined cytologically, triplo-6 was identified with chromosomes 6, but the previously designated triplo-5 and 7 were found to have been mistaken for each other. The anomalous trisomic previously suspected to be triplo-11 is reinterpreted from genetic evidence as a tertiary trisomic. The true triplo-11 was found among the aneuploid progeny of a triploid plant of var. Red Cherry and its true nature was verified by cytological examination and genetic test. Routine trisomic ratio tests were made in most combinations between the primary trisomics and a group of 42 genes, 5 of which are new and described here for the first time. To date trisomic segregations have been obtained for 30 genes on 11 of the 12 chromosomes. Several linkage groups that were previously assumed to be independent were associated with the same chromosome. Most of these relationships have later been confirmed by standard linkage tests. The remaining, unmarked chromosome, No. 12, has been tested with negative results against 18 additional genes, bringing to 60 the total number of genes tested with this chromosome. The probability of such failure was calculated on the basis of various assumptions and it seems highly improbable that a marker for chromosome 12 would not have been found in this number of genes. The contention that spontaneous mutant genes are not randomly distributed among the tomato chromosomes is thereby supported.

This publication has 18 references indexed in Scilit: