Isoenzyme Analyses of Progenies of the Crosses of Cucumis Species with Different Ploidities

The progenies of the crosses of Cucumis species with different ploidities [allotetraploid C.hytivus(2n=3x=26,HHCC),allotriploid(2n=3x=26,HCC) and reciprocal F_1 hybirds(2n=2x=19,HC/CH)] and their parental materials were comparatively examined to study the zymogram expressions of POD and EST isoenzymes in different organs.The results showed that the zymograms of POD and EST isoenzymes were richer in the flower buds than in the leaves,presenting obvious tissue specificity.In the same organs,the zymograms of the progenies of the crosses of Cucumis species with different ploidities were essentially identical,mainly appearing as the ones of the mutually complemented parental pairs as well as presenting the ones that the parental pairs lacked,which indicated that distant hybridization could widen the genetic base of cucumber.In addition,a majority of POD isozenzyme bands decreased in activity in the young leaves and flower buds as the ploidity decreased and this indicated that the gene dosages appeared to negatively correlate with the zymogram expressions of the POD isoenzymes.