西瓜用放射線誘致相互易位之研究Ⅰ：一些多染色體互換原種子合成

Studies on Radiation Induced Reciprocal Translocations in Watermelons. Ⅰ. Synthesis of Some Multiple Interchange Stocks

本試驗係利用40 Kr量之放射性gamma線照射處理西瓜乾燥種子，以誘致其相互易位。在放射線處理的當代植株中曾獲得許多具有不同程度之部分不穩性花粉粒之個體，其中多數均為單染色體互換之異型接合體，其單一的染色體群中含有四個染色體，更進一步採用具有高度不穩性之兩個體雜交，以合成含有──6染色體環形或──8染色體環形之多染色體互換原種，並測定其染色體互換頻率與不同程度不穩性間之關係，再加以自交以選出染色體互換之同型品系。

An attempt was made to induce reciprocal translocations in watermelons by irradiation of r-rays at the dosage of 40 Kr on dry seeds. A number of individuals with varying degree of partial sterility of pollen grains were obtained in the X1 plants. Most of them were recognized to be single interchange heterozygotes involved four chromosomes in a single complex. Further, multiple interchange stocks involved a ring of six or a ring of eight chromosomes were synthesized from the crosses between the two high sterile Individuals and the relation between the frequency of interchange and the degree of sterility was examined. They were self-pollinated for the selection of interchange homozygous lines.