摘要
小麦种子在科学探测和技术实验卫星上进行空间飞行，返回地面后浸种萌发，经不同时间培养后取根尖固定并观察根尖细胞染色体畸变情况。空间飞行可引起根尖细胞染色体畸变率的增加，其损伤随取样时间的延后呈下降趋势，说明空间飞行所诱导的染色体损伤可被部分修复；种子经辐射保护剂芥子碱和半胱氨酸预处理能显著降低空间飞行诱发的根尖细胞染色体畸变率，而经辐射敏化剂咖啡因预处理的情况则相反。
Dry seeds of wheat Tricham aestivum L. cv. Yang-mai No. 5 had beenaboarded on a satellite in space for 8days. After space flight the seeds weregerminated and cultured under 25℃,then the root tips were fixed in differentculture times to observe chromosomeaberrations. The chromosome aberration frequency of root tip cells increasedafter space flight and decreased with adelay of fixation time (Fig. 1). It hasbeen shown that the chromosome damage induced by space flight could bepertly repaired. The pre-flight treatedwith radiation protector sinapine andcysteine can reduce the chromosomeaberrations. However, radiation sensitizer caffeine has the opposite effectS(Fig. 2a-c). Wheat seeds hit by cosmic HZE-particles show similar results(Table 1). It showed that cosmic raysare the main factor for inducing thechromosome aberrations by spaceflight.
基金
863航天领域资助
关键词
小麦
根尖细胞
空间飞行
染色体畸变
space flight, chromosome aberrations,damage repair, cosmic rays
