辣椒不同品种种子萌芽期耐低温性及评价方法研究

以108个辣椒品种为试材, 测定了低温(18 ℃)下种子的相对发芽势、相对发芽率、相对胚根长、相对发芽指数和相对活力指数, 并采用极点排序法对辣椒不同品种的耐低温性进行综合评价。结果表明: 辣椒 不同品种种子萌芽期的耐低温性不同, 相对发芽率、相对发芽指数、相对胚根长和相对活力指数4项指标在不同品种间差异达显著水平(P<0.05)。选用上述4个指标, 采用极点排序法计算得到各品种的综合评价得分, 根据综合评价得分将108个辣椒品种分为10个耐低温品种, 9个低温敏感品种, 其余为中度耐低温品种。辣椒种子相对发芽势、相对胚根长与综合评价得分的相关性达到显著水平; 相对发芽率、相对发芽指数、相对活力指数与综合评价得分的相关性达极显著水平, 且相对活力指数与综合评价得分的相关性最高(r=0.899 9)。通过测定低温下辣椒品种萌芽期相关性状指标, 采用极点排序法可对辣椒种子萌芽期耐低温性进行快速、准确的评价。

Low-temperature tolerance of pepper at germination stage and its evaluation method

108 pepper cultivars were used to evaluate low-temperature tolerance at germination stage based on relative germination potential, relative germination percentage, relative germination index, relative radicle length and relative vigor index at 18 °C. The results indicate that the degree of tolerance varies among pepper cultivars, with significant differences (P<0.05) in relative germination percent, relative germination index, relative radicle length and relative vigor index. Based on the 4 indices, the evaluation score for each pepper cultivar is calculated by pole-sorting method. Using the evaluation scores, 108 pepper cultivars are classified into three categories. Whereas 10 cultivars are low-temperature tolerant, 9 cultivars are low-temperature sensitive and the rest cultivars are moderately low-temperature sensitive. The relative germination potential and relative radicle length of different pepper cultivars exhibit significantly correlation with the evaluation scores. The correlation among relative germination percent, relative germination index, relative vigor index and the evaluation scores is extremely significant. The relative vigor index and the evaluation scores exhibit the highest correlation (r=0.899 9). The results indicate that pole-sorting analysis is an effective method for preliminary evaluation of low-temperature tolerance of pepper in terms of relevant characteristics at germination stage.