Study on growing and photosynthetic characteristics of new varieties of Bupleurum chinense DC. | 新类型北柴胡的生长与光合特性研究

chinois. 比较研究北柴胡新类型与传统类型在生长与光合特性上的差异，为选育北柴胡良种提供依据。利用TPS-1光合作用系统，测定苗期和花果期宽叶型（KY）北柴胡与原始类群中占绝对优势的中间型（ZY）北柴胡叶片的光合指标及相关环境因子，同时取样测量其地上形态指标和各部分的生物量，比较2种类型北柴胡各指标的差异。苗期和花果期，KY北柴胡的株高、茎径、叶长（花果期除外）、叶宽和总叶面积均显著（P＜0.05）高于ZY北柴胡，叶长宽比则以ZY北柴胡显著（P＜0.05）高于KY北柴胡。苗期2种类型北柴胡的净光合速率（Pn）、蒸腾速率（Tr）、气孔导度（Gs）日变化曲线均呈单峰型，ZY北柴胡的Pn显著（P＜0.05）高于KY北柴胡；花果期二者Pn、Tr、Gs日变化曲线均呈双峰型，且KY北柴胡的Pn显著（P＜0.05）高于ZY北柴胡。根据Pn、胞间CO2浓度（Ci）、气孔限制值（Ls）的变化方向，推测花果期KY北柴胡光合“午休”主要受气孔因素限制，而ZY北柴胡主要受非气孔因素限制。苗期影响北柴胡Pn的环境因子主要为气温，花果期主要为空气相对湿度和大气CO2浓度。苗期和花果期，KY北柴胡根、茎、叶、花果及总生物量均显著（P＜0.05）高于ZY北柴胡；ZY北柴胡根、茎、叶生物量分配比例基本高于KY北柴胡，但花果生物量比例则显著（P＜0.05）低于KY北柴胡。KY北柴胡在决定产量的生殖生长阶段具有较高的Gs和较低的Ci，Pn较强，生物量积累高，源库关系较为合理，源充足，库大，具有高产潜力。

anglais. To provide basis for breeding fine variety of B. chinense, researches into growing and photosynthetic characteristics of new and traditional types of B. chinense are conducted. It is tested to find out leaf photosynthesis index and relative environmental factors of broad leaf type (KY) and medium leaf type (ZY) B. chinense dominated in primitive groups during their seeding and flowering and fruiting stages by TPS-1 photosynthesis system. Meanwhile, sampling measurements are conducted in their ground morphological index and biomass to work out index differences of the two types of B. chinense. The height, stem diameter, leaf length(except the flowering and fruiting stages), leaf width and total leaf area of KY are all significantly higher than those of ZY（P＜0.05）, and leaf length/leaf width of ZY is evidently higher than KY(P＜0.05) during their seeding and flowering and fruiting stages. Diurnal variations of net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs) in two varieties of B. chinense in seeding stage showed unimodal curve and Pn of ZY is evidently higher than KY（P＜0.05）while they all showed bimodal curve in flowering and fruiting stage and Pn of KY is evidently higher than ZY（P＜0.05）. It is inferred that KY’s photosynthetic “midday depression” phenomenon of flowering and fruiting stage is mainly confined by stoma according to the alteration direction of Pn, Ci, Ls while ZY is mainly confined by factors of non-stoma. Environmental factor that influences Pn of B. chinense is Ta chiefly in seeding stage, RH and Ca chiefly in flowering and fruiting stage. The root, stem, leaf, flower and fruit and total biomass of KY are significantly higher than those of ZY(P＜0.05) . And the distribution ratio of root, stem, and leaf biomass of ZY is basically higher than those of KY while flower and fruit biomass of ZY is evidently lower than that of KY(P＜0.05) during their seeding and flowering and fruiting stages. KY holds higher Gs and lower Ci in reproduction growth stage which determines yield. Also, it has stronger Pn, higher biomass accumulation, more reasonable source-sink relationship, sufficient source, great sink and great potentiality of high production.