不同品种美国山核桃叶绿素荧光特性的比较

Comparative studies on the chlorophyll fluorescent characteristics in leaves of different pecan cultivars

研究了不同品种美国山核桃的叶绿素荧光特性和光合效率,旨在为其优良品种选择和高效栽培提供科学依据。以8个美国山核桃品种为试材,田间测定了其叶绿素荧光参数及叶片基本性状。结果表明,不同品种间的PSⅡ原初光能转化效率(primarily photochemical efficiency ofphotosystem Ⅱ,Fv/Fm)、PSII潜在活性(potential activity of photo-systemII,Fv/F0)、非光化学猝灭系数(non-photochemical quenchingcoefficient,qN)均存在显著或极显著差异,其中金华1号、UM9-82个品种的Fv/Fm值分别为0.809、0.796,Fv/F0值分别为4.266、3.910,均显著高于其它品种,表现出良好的光合性能;光合量子产额(effective quantum yield of photosystem Ⅱ,Yield)和光化学猝灭系数(photochemical quenching coefficient,qP)未达显著差异。不同品种叶片比叶重和叶绿素含量及各组分均存在显著差异。相关分析表明,叶绿素及各组分含量与Yield均呈显著或极显著负相关。据此,湖南地区要引种外地具有优良光合性能的美国山核桃作为栽培品种时,在供试8个品种中,金华1号、UM9-82个品种可为首选品种。

The chlorophyll fluorescent characteristics and photosynthetic efficiencies of different pecan cultivars were investigated for providing scientific basis for choosing excellent cultivars and high efficiency cultivation. The chlorophyll fluorescent parameters and the leaf basic characters of 8 pecan cultivars were measured.The primarily photochemical efficiency of photosystem II （Fv/Fm）, potential activity of photosystem Ⅱ （Fv/Fo）, non-photochemical quenching coefficient （q^N） showed significant or highly significant difference among cultivars. The Fv/Fm values of cultivar Jinhua No.1 and UM9-8 were 0.809 and 0.796, and the Fv/Fo values were 4.266 and 3.910, respectively. They were all significantly higher than those of other cultivats studied.The results illustrated that the photosynthetic properties of the two cultivars were by far the best among the 8 tested cultivars. The effective quantum yield of photosystem Ⅱ （Yield） and the photochemical quenching coefficient （q^P） did not show significant difference. Specific leaf weight and chlorophyll contents showed significant or highly significant difference among cultivars. The results of correlation analysis showed that the Yield had a significant or highly significant negative correlation with chlorophyll content. Therefore,it is suggested that if pecan cultivars from other parts of the country are to be introduced into Hunan area as field-grown cultivars, the Jinhua No. 1 and UM9-8 may be the top-priority cultivars among the 8 cultivars studied.