Cucurbit Genetics Cooperative Report 1:29 (article 27) 1978
Genetic Variation of Esterases and Peroxidases in an Interspecific Cucurbita Cross
J. T. Puchalski, R. W. Robinson, and J. W. Shail
New York Agricultural Experiment Station, Geneva, NY 14456
The aim of this preliminary study was to investigate the inheritance and linkage relations of multiple electrophoretic forms of esterases and peroxidases in an interspecific cross between Cucurbita moschata cv. 'Butternut' and C. martinezii. The zymogram method, with starch gel as the separation medium, was used to analyze isozymes extracted from young leaves of the parents, F1, F2, and backcross of the F1 to C. moschata.
C. moschata and C. martinezii differed in their pattern of both enzyme systems. The largest differences observed were for fast migrating anodic isoesterases. Cucurbita moschata contained two very active peroxidase bands, Px1, and Px3, that were not present in C. martinezii. Cucurbita martinezii showed three additional specific peroxidase bands, Px2, Px4a, and Px4b. The bands Px1, Px2, Px3, and Px4a were all found in the F1, but their intensity was lower than in the respective parents. The F2 population segregated for all these bands, but Px1 was always associated with Px3 and segregates with Px2 always had Px4a. The backcross (F1 x C. moschata) generation also showed a similar association of Px1 with Px3 and of Px2 with Px4a. Nineteen backcross plants had a peroxidase zymogram pattern characteristic of C. moschata, and nine were similar to that of the F1.
Eleven electrophoretic esterase bands were found in C. moschata, but only four occurred in C. martinezii. Four isoesterase bands showing the fastest migration on the gel and two bands with a more moderate rate of migration, found in C. moschata but not in C. martinezii, were under dominant genetic control. They occurred in the F1 and segregated in the backcross (F1 x C. moschata) as well as in the F2. Cucurbita martinezii contained two specific esterase bands, one very active and the other lightly stained; they were both present in the F1 and segregated independently in the F2 and backcross generations.
Linkage was not detected between esterase and peroxidase genes and morphological traits.