不同品种糜子幼苗根系对干旱胁迫的生物学响应

Biological Response of Seedling Roots in Different Broomcorn Millet Genotypes to Drought Stress

采用盆栽的方法,以6个糜子品种(农-021;农-034;农-092;品-011;品-029;品-076)作为试验材料,研究了干旱胁迫下不同品种糜子根系的形态学与生理学特征。结果表明:干旱胁迫下糜子的株高、叶面积、地上重、根重、总根长、根活力及根系SOD活性均明显降低,不同品种间的变化趋势相似,但变化幅度明显不同。中度干旱胁迫下,上述指标最小的下降幅度分别为13.39%、18.33%、8.11%、9.99%、20.92%、10.18%、32.83%;而最大的下降幅度分别为22.67%、38.22%、24.15%、28.87%、41.07%、28.89%、44.97%。同一含水量条件下不同供试品种间根系的形态与生理学特征及同一糜子品种在不同供水条件下的根系形态与生理学特征均存在着明显的差异,表明这两种性状的差异是由基因型和环境因素共同决定的。根重、总根长、根活力、Pro含量及根系SOD活性变化在材料间存在显著差异,在一定程度上反映了糜子品种的抗旱性强弱,可作为糜子苗期鉴定抗逆性强弱筛选的生理指标。在供试的6个品种中,农-021对干旱环境的适应性最强。

The differences in morphological and physiological characters of six broomcorn millet varieties （ NONG- 021, NONG-034, NONG-092, PING-011, PING-029, PING-076） to drought stress were studied on the Experimental Farm of Shanxi Normal University with pot culture. The results showed that （ 1 ） Comparing with the control group, the broomcorn millet seedling under drought stress has small height and short root length. The plant height, leaf area, the dry weight of shoot and root, total root length, root activity and The change tendency of different genotypes was similar, but the range of c root SOD activity decreased drastically hanges was different remarkably. Under moderate drought stress, the plant height, leaf area, the dry weight of shoot and root, total root length, root activity and root SOD activity of the best broomeorn millet variety descended 13. 39%, 18. 33% ,8. 11% ,9. 99% 20.92% ,10.18% ,32.83% respectively. Meanwhile, the Indices of the worst broomcorn millet variety descended 22.67% ,38.22% ,24.15% ,28.87% ,38.64% ,28.89% ,44.97% respectively. （2） The morphological and phys- iological characters of root were significantly different under different levels of drought stress and among different broomcorn millet genotypes under same drought stress. This implied that the two traits were controlled by genotype and external factors. （ 3 ） The results indicated that the changes of root dry weight, total root length, root activity, the root proline content and SOD activity had a significant positive correlation with the strength tolerance of broomcorn millet and reflected the stress resistance among materials in broomcorn millet , So they could be reference to screen water efficient uptake of broomcorn millet. （4） The result also showed that NONG-021 was most tolerant to drought stress in the genotypes.