辐射诱发柑桔无籽突变机理的研究

RESEARCH ON MUTATION MECHANISM FOR SEEDLESS FRUIT OF IRRADIATED SWEET ORANGE

经辐射处理的甜橙花粉母细胞减数分裂中出现染色体易位、倒位、不联会的单价体等异常现象。由此而引成的花粉形态出现各种变异,育性降低,因而产生无籽少籽的果实。经统计分析,染色体畸变的细胞频率与果实的种子数为显著的负相关,花粉发芽率与果实的种子数为显著的正相关。在各种染色体异常中,不联会的单价体是引起花粉败育产生无籽果实的主要原因。

The chromosomes of pollem mother cells of the sweet orange (Citrus Sinensis L. ) exhibited translocation,inversion and a synapsis during meiosis after irradiation treatment. These chromosomeal mutations and abortion in the pollen mother cells resulted in decreased fertility and the production of seedless or commercially seedless fruits. Statistical analysis of the data indicated that there was marked inverse relation between the frequency of ceiis with chromosomal mutation and number of seeds in fruit;and marked positive correlation between germinative rate of pollen and number of seeds in fruit. Of all the chromosomal aberrations, the appearance of asynapitc univalent and resultant pollen abortion was the major cause of seedless fruits.