花青素合成基因bz1和bz2在莲藕染色体上的定位

Bronze 1(bz1)是编码UDP葡萄糖类黄酮葡糖基转移酶(UFGT)的基因，UFGT是种子糊粉层中的花青素生物合成酶。Bronze 2(bz2)是另一种花青素生物合成基因，与类黄酮的酰化、糖基化、转运、沉积等有关。以生物素标记的重组质粒pUC19中含有玉米bz1和bz2基因作为探针，与莲藕(Nelumbo nucifera L．)的有丝分裂染色体标本进行荧光原位杂交(fluorescence in situ hybridization，FISH)。结果显示，bz1和bz2基因分别位于莲藕的第2和第4号染色体长臂上，与着丝粒的相对距离分别为79％和67％。这是首次提供莲藕染色体上的FISH杂交信息，从而为增加莲藕染色体组中的遗传标记和建立遗传图谱奠定基础。

Chromosomal Localization of Anthocyanin Biosynthetic Genes bz1,bz2 in Lotus

Both bronze 1 (bz1) and bronze 2 (bz2) are anthocyanin biosynthetic genes,and related to development of aleuronic layers of maize seeds.The bz1 gene encodes UDP glucose flavonoid glucosyl-transferase (UFGT),an anthocyanin biosynthetic enzyme in the aleuronic layer of the seed,which modifies purple aleurone and plant color to pale or reddish brown,anthers yellow-fluorescence.Bronze 2 is another anthocyanin biosynthetic gene,its potential function is reflavonoid (acylation),glycosylation transport or deposition.Using maize bz1 and bz2 gene inserted into pUC19 labeled by the biotin as the probes respectively,bz1 and bz2 genes have been assigned to metaphase chromosome of lotus (Nelumbo nucifera L.) by fluorescence in situ hybridization (FISH).The red hybridization signals indicated the bz1 gene and bz2 gene on homologous chromosome 2 and chromosome 4,respectively.The percent distances from the centromere are 79% and 67%,respectively.The current studies would advance the addition of genetic markers and the construction of genetic map in lotus.