Application Of Special PCR To Detecting Ae Gene Of Maize

Maize is one of the most important crop plants in the world and corn starch is a main starch source of human being. The starch is a main backlog material of the corn seed, the maize starch is about 70% of the seed. The starch exists in two forms: Amylopectinand amylose. The common corn starch is a mixture of Amylopectinand amylose and their content is about 28% and 72% respectively.Because of its special physical and chemical properties, amylose starch is a kind of high additional value starch. Amylose starch is an important industrial material and applied in extensively in more than 30 fields. However,the amylose content in common corn is rather low,generally between 22%-28%.This limited its application in industry because the cost of separating the high amylose from the common corn is very high. Thus, it is necessary for corn breeders to explore high amylase corn to fit for industrial use. The breakthrough of high amylose research is the discovery of the ae gene(amylase extender)mutation body, the amylose contents raised consuming with ae gene. Afterwards other modifying genes are discovered, they affect the ratio of amylopectin and amylose. In the current research, 22 pairs of specific primers were designed according to the ae gene sequence published in Genbank. Three inbred lines of common corn and three ae mutant inbred lines and three materials of hybrid lines were marked, through polyacrylamid gel eletrophoresis detecting,the result as following: (1) Primer 4,7,10,11,15 and 18 did not show any bands in the material 1-9. (2) Primer 1,12,14,16,17 and 19 showed target bands in the material 1-9,the bands have no difference. (3) Primer 3,6,20 and 21 showed many bands in the material 1-9, it contained target bands and other unspecific bands. (4) Primer 2 showed many bands in the material 1-9,but it is not contained target bands. (5) Primer 8,9,13 and 22 showed target bands in some material and the bands have no rule. (6) Primer 5 showed target bands in material 1,2,4,5,7,8 and have no bands in material 3,6,9. The primer 5 showed strong specialty ,using primer 5 to detect 21 hybrid lines(material 11-30).Primer 5 showed target bands in the hybrid of common inbred lines and ae material(material 11,12,13,14,15,16,17,18,19 20,21,22,23,24,25,26)have no bands in common hybrid (material 27,28,29,30) It is concluded that this pair of primer can distinguish hybrid lines AeAe from hybrid of high amylose maize Aeae. It is an effective technology to improve inbred lines in common use to inbred lines of high amylose maize.