| High amylose maize kernel have became the main source of bio-degradation plastic. It was very costly to separate amylose from normal maize so breeders began to select maize hybrid with high amylose.At present,the normal method which seleted maize variety with high amylose was backcross.Thus,gene ae that controlled the content of maize amylose was introduced into other fine inbred lines which were cultured into high amylose maize by backcrossing and self-bred at least six generations,which was not only time-consuming but laborious.Four high amylose maize inbred lines,eight normal inbred lines and ten hybrids from normal and high amylase maize inbred lines were used as materials. The differences among sequence of ae gene of different maize were investigated,which established a good base to mark gene ae and shorten the period of breeding.The two representative varieties of high amylose and normal maize also were studied to compare the difference of the enzymes activities associated with starch synthesis in the developing grains. The main results as follows:1. According to the sequence of gene ae reported in Genbank, 23 pairs specific primers were designed and carried out PCR above materials. PCR production were separated and the sequence were measured.The results indicated that the sequence of ae gene selected in this research was quite conservative,and only one deletion with eight bases at locus between 19200 and 19207 was found;one insert with three bases at locus between 19256 and 19258,and one transversion with one base(A→T) at locus 19244.2. The study of enzyme activity showed that in high amylose maize,the activity of granule-bound starch synthase (GBSS) was higher than normal maize,but that of the soluble starch synthase (SSS),starch branching enzyme (SBE) were lower than normal maize.The decrease of total starch and the increase of amylose percent in total starch were resulted from the integrated action of SSS,GBSS and SBE. |
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