摘要
Abstract
The fast chlorophyll a fluorescence transient and its parameters were measured by a PEA lumi-noscope (plant efficiency analyzer from Hansatech) in two varieties of pumpkin( Cucurbita pepo L. ) , Ming-zhutezao with lower heat - resistant capability and Lubo with higher one. The parameters of chlorophyll fluorescence did not change sharply from 36℃ to 40℃. As the temperature increasing from 441, Fo went up slowly , but Fm, Fv and Fv/Fm came down in wide range, and their variations of Mingzhutezao were larger than those of Lilbo. After treated for 15 minutes at 441 ,the K - phase of Mingzhutezao appeared at about 0. 8 ms on the fluorescence kinetics curve, so the regular 0 - J - I - P transient was transformed to an O-K-J-I-P one. Meanwhile, the K -phase of L&bo appeared when the treatment time was up to 25 minutes at 44X1. When the temperature was 48℃, the K - phase of Mingzhutezao and Lubo appeared after treated for 2 minutes and 6 minutes respectively. As the temperature of heat stress increased from 36℃ to 50℃ , RC/Cso reduced gradually, while Fvi/Fv rose up.关键词
热胁迫/叶绿素荧光参数/K峰/光系统Ⅱ/两葫芦Key words
Heat stress/ Chlorophyll fluorescence parameter/ K-phase/ Photosystem II / Pumpkin分类
农业科技
