CHARACTERIZATION AND APPLOCATION OF SELF-INCOMPATIBILITY GENES IN JAPANESE PEARS

采用等电聚焦聚丙烯酰胺凝胶电泳（IEF-PAGE）技术，研究了日本梨自交不亲和基因型与花柱蛋白的关系。酒吧culta）。一系列对应于自交不亲和基因型的花柱特异性蛋白（S蛋白），S1-S5，仅在含有pH3.5 -9.5两性蛋白的凝胶的阴极端被鉴定。因此，这些蛋白质的pI似乎高于9.5，并且每个蛋白质条带从阴极端排列如下：S1、S4、S5、S2和S3。在蔷薇科植物的花柱中也发现了相似的碱性蛋白质，表明蔷薇科植物的自交不亲和机制相似。这些蛋白条带显示了核糖核酸酶活性，但酶活性与自交不亲和机制的关系尚不清楚。同时，通过对S基因型未鉴定品种的带型分析，推测'朝珠'、'赤穗'、'丰水'和'桂水'的基因型分别为S1 S5、S3 S4、S3 S3和S4 S5。双向电泳显示S_1、S_5和S_3条带分别为3、4和4个斑点，表明该蛋白质可能含有多个亚基，也可能是由多条pI值相近的蛋白质条带组成的复合体。

Relationships between self-incompatibility genotypes and stylar proteins were investigated by isoelectricfocusing polyacrylamide gel electrophoresis (IEF-PAGE) in Japanese pear (Pyrs serotina Rehad. bar. culta). A series of style-specific proteins corresponding to self-incompatibility genotypes(S-protein), S1-S5, were identified just at the cathodic end of the gel containing ph 3.5-9.5 ampholines. Thus, the pIs of these proteins seemed to be higher than 9.5, and each protein band was arranged from a cathodic end as follows ; S1, S4, S5, S2 and S3. Similar basic proteins were also present in the styles of P.communis, P.ussuriensis and Prunus, and thus similar mechamisms of self-incompatibility were suggested in order species of Rosaceae. These protein bands showed RNase activity, but the relation of the enzyme activity to self-incompatibility mechanisms was not clarified. Meanwhile, by inspecting banding patterns in S-genotype unidentified cultivars, we could assume the genotypes of 'Choju', 'Chikusui', 'Hohsui' and 'Kisui' to be S1S5, S3S4, S3S3 and S4S5, respectively. The S1-, S5- and S3-bands separated by IEF-PAGE, however, consisted of 3, 4 and 4 spots respectively when subjected to two-dimensional electrophoresis, suggesting that the protein either possesses several subunits or is a complex of several protein bands with exactly close pIs.