Cucumis属3种不同倍性种间杂交后代的同工酶分析

以3种不同倍性的Cucum is属种间杂交后代异源四倍体C.hy tivus(2n=4x=38,HHCC)、异源三倍体(2n=3x=26,HCC)和正反交种间杂种F1(2n=2x=19,HC/CH)]及其双亲为试材,比较研究了过氧化物酶(POD)和酯酶(EST)同工酶在不同器官中的酶谱表达特性.结果表明,花蕾中的POD和EST同工酶谱带都比叶片中的丰富,表现出明显的组织特异性.在相同器官的同一酶系统中,3种不同倍性种间杂交后代的酶谱基本一致,主要表现为互补双亲的酶带,同时出现了双亲所没有的酶带(POD4c和EST3b等),表明远缘杂交扩大了黄瓜的遗传基础.此外,在幼叶和花蕾的POD同工酶中,大部分酶带活性随染色体倍性增加而减弱,表明基因剂量与POD同工酶酶谱的表达呈负相关.

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.