西瓜二倍体及同源多倍体遗传差异的AFLP分析

试验以蜜枚和JM西瓜品种的纯合二倍体及其人工诱导的同源四倍体、三倍体为材料,对不同倍性西瓜AFLP标记的分子遗传变异进行了比较。结果表明:共筛选48对引物组合,获得4800～5000条位于50～600bp的片段,大部分引物组合扩增出的不同倍性之间的AFLP条带没有明显差异;蜜枚品种西瓜具有多态性的条带有3条,其中1条为四倍体特有带,1条为三倍体特有带,1条为二倍体特有带;JM西瓜具有多态性的条带有7条,3条为JM4x特有带,2条为JM3x特有带,2条为JM2x特有带,不同倍性西瓜之间多态性较低。同源四倍体和相应的二倍体相比,有特异性片段的消失或增加,也有扩增出双亲皆有或皆无而三倍体F1消失或增加的DNA片段。

AFLP Analysis of the Genetic Diversity Between Diploid and Autopolyploidy Watermelon

Analysis was c on ducted with different ploidy watermelon materials,including diploid,triploid crossed with4x×4x and autotetraploid induced by colchicines of Mimei and JM w atermelon varieties by using AFLP molecular markers.Re-sults showed that using amplified fragment length polymorphism(AFLP)could identify the genetic varia tion of watermelon.We employed48AFLP primer combinations on different ploidy ,a total of4800～5000AFLP bands were observed.AFLP bands of different ploidy watermelon amplified by most AFLP primer pairs were not apparently diffe rent.It indicated low ge-netic variation among4x,3x,2x.3bands of Mimei' s and7bands of JM's were polymorphic,there were1specific band in M2x,1spec ific band in M3x and1specific band in M4x when compared with its other ploidy .There were2specific bands in JM2x,2specific bands in JM3x and3specific b ands in JM4x when compared with its other ploidy.There were present or ab-se nt of specific bands of autotetraploid compared with diploid,this reflected th at DNA molecular genetic structure was changed by colchicines and allelic variat ion of autotetraploid.There were present or absent of specific bands of tripl oid F 1 compared both parents,this reflected that gene mutation occurred in the fer tilization process after cross of the tetraploid and diploid.