镉胁迫对不同甜玉米自交系幼苗生长的影响及其相关简单重复序列分子标记初筛

为探究不同甜玉米自交系幼苗期对镉的响应差异,发掘与甜玉米苗期耐镉性状相关的分子标记位点,选取13份甜玉米自交系进行镉胁迫处理(Cd浓度为0.01 mol·L^-1),综合评价甜玉米幼苗生理指标差异,并寻找与甜玉米苗期耐镉性相关的简单重复序列(SSR)分子标记。结果显示,从耐镉性判断,KY188、M114A为敏感型自交系,T96-4、M3、T35和T8-1为耐受型自交系。与对照处理相比:KY188(敏感型)经过镉胁迫处理后,叶绿素含量随时间推进显著(P<0.05)降低,苗高、总根数、根长、地上部鲜重和干重、地下部鲜重和干重、总鲜重、总干重分别显著(P<0.05)降低了18.87%、24.32%、21.13%、58.86%、2.04%、33.77%、26.11%、47.11%、14.29%;T96-4(耐受型)经过镉胁迫处理后,上述指标无显著变化。通过相关性分析,共检测到9个与甜玉米苗期耐镉性状相关的SSR标记,分别位于第2、3、4、5、6、8、9、10号染色体上。

Influences of cadmium stress on seedling growth of different sweet corn inbred lines and screening of associated molecular markers via simple sequence repeats

In order to explore the responses of different sweet corn inbred lines to cadmium at seedling stage and to screen molecular markers associated with these responses, 13 sweet corn inbred lines were treated with 0.01 mol·L^-1 cadmium, comprehensive evaluation of these sweet corn inbred lines was carried out based on physiological indexes, and the associated molecular makers were identified via genomic simple sequence repeats (SSR) markers. It was shown that KY188 and M114A were sensitive materials, and T96-4, M3, T35 and T8-1 were tolerant materials by Cd tolerance analysis. Compared with the control (without Cd), the chlorophyll content of KY188 (Cd sensitive inbred line) treated with Cd significantly (P<0.05) decreased with time, and its plant height, root number, root length, fresh weight of shoot, dry weight of shoot, fresh weight of root, dry weight of root, total fresh weight of plant, total dry weight of plant were significantly (P<0.05) decreased by 18.87%, 24.32%, 21.13%, 58.86%, 2.04%, 33.77%, 26.11%, 47.11% and 14.29%, respectively. However, the tolerant inbred line T96-4 showed no significant changes in the above indexes after Cd treatment. Through correlation analysis, 9 SSR markers were screened out on the 2nd, 3rd, 4th, 5th, 6th, 8th, 9th and 10th chromosome.