玉米种子老化过程中EST同工酶变化与染色体畸变的研究

Esterase Changes and Chromosome Aberration in Maize Aging Seeds

对玉米自交系Mo17种子分别进行 5 8℃热水和 4 5℃恒温老化处理并对种子老化过程中种子发芽率、EST同工酶酶谱变化与染色体畸变规律进行了研究。结果显示 :Mo17玉米种子萌发一天的种子胚EST酶谱共表现为 14条清晰条带 ,5 8℃热水处理 30min后 ,有四条酶带 (Rf值为 0 4 4、0 4 7、0 77、0 80 )消失 ,酶带号为 1、2、6、7、9的五条酶带着色变浅 ,由一、二级酶带变为二、三级酶带。 4 5℃恒温老化处理 6 0d后 ,Mo17种子EST酶谱中编号为 2和 5的两条酶带 (Rf值为 0 33、0 39)消失。处理 70d后 ,种子发芽率降至 39% ,酶带号为 11、12、13、14的四条酶带消失。随着老化时间延长 ,老化程度不断加重 ,发芽率低的玉米种子其根尖染色体畸变率相对较高 ,单桥、双桥、断片、落后及其它染色体畸变类型均被观察到。 5 8℃热水老化其发芽率降至 5 %时 ,染色体畸变率上升为 12 2 2 %。

The viability, esterase changes and chromosome aberration of the maize seeds Mo17 artificially aged by hot water(58℃±1℃)and high temperature(45℃)were investigated. The results showed that 14 distinguishable bands appeared in the profiles of untreated Mo17 seed. Four esterase bands with Rf value of 0 44, 0 47, 0 77 and 0 80 in Mo17, however, disappeared after aged by hot water for 30 minutes and five bands' (band 1, 2, 6, 7, 9) intensity changed from strong one to light one. The seeds of Mo17 aged in 45℃ chamber for 60 and 70 days had 2 bands (Rf: 0 33、0 39) and 4 bands (band 11, 12, 13, 14) missed, respectively. Higher chromosome aberration happened in the seeds with lower viability, and chromosome bridges, chromosome breakage and chromosome fragments were detected in aged seeds. When the germination percentage of Mo17 was reduced to 5%, the chromosome aberration rate raised to 12 22%.