Abstract
Effect of high temperature on meiotic homologous chromosome pairing of common wheat was examined. According to the experimental results, constant high temperature of 30°C significantly reduced homologous pairing compared with 15, 20 and 25°C, and such effect was recognized only when the PMCs of some limited stage immediately before premeiotic S phase were exposed to the temperature. Besides, the high temperature did not affect the pairing of both arms of an isochromosome (1A-long-arm) at all.
It was strongly suggested from these results that (1) high temperature of 30°C disturbs the process of pairing at a step which controls premeiotic inter-homologues attraction, creating such a situation as homologues are spatially kept away each other, and (2) this step may closely be connected with a peculiar stage sensitive to the high temperature. A similarity of acting mechanism among high temperature, colchicine and Ph allele was also discussed.
