| 摘要: |
| 【目的】确定快菜萌发期耐热评价指标，筛选萌发期耐热种质，为快菜大规模鉴定和耐热机理研究提供方法及优质资源。【方法】以耐热性不同的6份快菜品系（编号分别为B18、B33、B11、B15、B2、B36）为材料，在25（对照）,35,37和42 ℃下进行萌发试验，分析不同快菜品系对高温胁迫的响应，确定模拟萌发期高温胁迫的最适温度。在模拟高温胁迫下，以38份快菜品系（编号为B1-B38）为材料，测定12个与萌发期耐热性相关的指标，以各指标的耐热系数（γ）作为基础，利用相关性分析、主成分分析、隶属函数分析、逐步回归分析和聚类分析方法，对不同快菜品系萌发期耐热指标进行筛选，对耐热性进行评价。并对38份快菜品系苗期和成株期的田间热害指数及耐热性进行综合评价。【结果】随着胁迫温度升高，6份快菜品系的发芽率、发芽势、发芽指数、活力指数与对照相比均下降，37 ℃是模拟萌发期高温胁迫的最适温度。在37 ℃模拟高温胁迫下，12个快菜萌发指标均受到不同程度的影响，相关性分析发现，各指标间存在一定的相关性，主成分分析中5个综合指标可代表不同快菜品系萌发期耐热性原始信息量的92.64%。根据隶属函数中不同品系萌发期耐热性综合评价值（D值）可知，B3品系耐热性最强，B17品系耐热性最差。与快菜耐热性密切相关的指标是活力指数、芽长和根长。38份快菜材料按萌发期耐高温能力可分为3大类，其中20个品系对高温不敏感，8个品系对高温敏感，10个品系对高温有较强的耐受性。苗期和成株期耐热性田间鉴定结果与萌发期室内鉴定结果基本一致。【结论】快菜萌发期模拟高温胁迫最适温度为37 ℃，活力指数、芽长和根长可作为快菜萌发期耐热性鉴定的首选指标，获取了38份快菜材料萌发期耐热性数据。 |
| 关键词: 快菜 萌发期 高温胁迫 耐热指标 耐热性评价 |
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| 基金项目:海南省重大科技计划项目（ZDKJ2017001）；海南省重点研发计划项目（ZDYF2019066）；国家现代农业产业技术体系建设专项资金项目（CARS-23-G52） |
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| Indexes screening and identification of heat tolerance at germination stage in different lines of seedling-edible Chinese cabbage |
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PANG Qiangqiang,SUN Xiaodong,CAI Xinglai,et al
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| Abstract: |
| 【Objective】To provide identification method and excellent resources for large-scale identification and study on heat resistance mechanism of seedling-edible Chinese cabbage,the heat resistance evaluation indexes and germplasm resources were screened at germination stage.【Method】Germination experiments were conducted at 25 (control),35,37 and 42 ℃ for 6 lines (B18,B33,B11,B15,B2 and B36) with different heat resistances.The responses of different seedling-edible Chinese cabbage lines to high temperature stress were analyzed to determine the optimum temperature for simulating high temperature stress during germination.Under simulated high temperature stress,38 seedling-edible Chinese cabbage lines (B1-B38) were tested and 12 indexes relating to heat tolerance of different seedling-edible Chinese cabbage lines were determined.Taking heat resistance coefficient (γ) of each indicator as basis,and the heat tolerance of different seedling-edible Chinese cabbage lines was evaluated by correlation analysis,principal component analysis,membership function analysis,regression analysis and cluster analysis.And the heat injury index and heat resistance of 38 seedling-edible Chinese cabbage at field seedling stage and adult stage were comprehensively evaluated simultaneously.【Result】Compared with the control,germination rate,germination potential,germination index and vigor index of the 6 seedling edible Chinese cabbage lines decreased with the increase of temperature.The comprehensive analysis showed that 37 ℃ was the optimum temperature to simulate high temperature stress during germination.Under 37 ℃ high temperature stress,12 germination indexes were affected to different degrees.Correlation analysis found that there was correlation among indexes,and principal component analysis of the 5 comprehensive indexes could represent 92.64% of original information.According to comprehensive evaluation (D value) of different lines at germination period in membership function analysis,B3 line had the strongest heat resistance,while B17 line had the worst. Stepwise regression analysis showed that indexes closely related to heat resistance of seedling edible Chinese cabbage were vigor index,bud length and root length.The 38 seedling edible Chinese cabbage lines were classified into 3 types according to high temperature tolerance at germination stage.Among them,20 lines were insensitive to high temperature,8 lines were sensitive to high temperature,and 10 lines were strong tolerance to high temperature.The results of field identification at seedling and adult stage were consistent with those at germination stage.【Conclusion】The optimal temperature of simulated high temperature stress in germination period of seedling-edible Chinese cabbage was 37 ℃.Vigor index,bud length and root length could be used as preferred indicators for identification of heat resistance in germination period,and the heat resistances of 38 seedling-edible Chinese cabbage lines at germination stage were attached. |
| Key words: seedling edible Chinese cabbage germination period heat stress heat tolerance index heat-resistant identification |
