董晶晶等

摘要：设置3个土壤水分梯度，分别为对照组（CK）、轻度干旱处理组（HW）、重度干旱处理组（LW），测定牛膝菊（Galinsoga parviflora）的生长及光合特性。结果表明，①就株高、茎干重、根干重、叶生物量比和根生物量比而言，3个处理差异不显著（P>0.05）；叶根比、比叶面积、叶面积比皆为HW最高。②随着光照度的增加，CK的牛膝菊净光合速率日变化呈现升高—降低—升高的趋势，HW和LW的牛膝菊净光合速率日变化呈现先升高后降低的趋势；光补偿点CK最高，为9.07 μmol/（m2·s）；光饱和点为HW最高，其数值为1 492.59 μmol/（m2·s），LW最低，其数值为79.25 μmol/（m2·s）；LW的表观量子率最低；在最大光合有效辐射下，CK组的最大净光合速率最高，为13.96 μmol/（m2·s）。③随着土壤水分的递减，牛膝菊净光合速率、气孔导度、蒸腾速率皆呈下降趋势，胞间CO2浓度变化为HW>CK>LW。

关键词：牛膝菊（Galinsoga parviflora）；土壤水分；植株生长；光合特性

中图分类号：S451.1；Q948.112+3 文献标识码：A 文章编号：0439-8114（2015）12-2910-04

DOI：10.14088/j.cnki.issn0439-8114.2015.12.025

Effects of Different Soil Moisture Content on the Growth and Photosynthetic

Characteristics of Galinsoga parviflora

DONG Jing-jing1，QI Shu-yan1，2，YAO Jing1，LI Xiao-chun1，GUO Ting-ting1

（1.College of Biology Science and Engineering， Shenyang University， Shenyang 110044，China；

2.Liaoning Key Laboratory of Urban Integrated Pest Management and Eco-Security， Shenyang 110044，China）

Abstract： The growth and photosynthetic characteristics of Galinsoga parviflora were measured by setting the three soil water gradients， including contrast（CK）、mild drought group（HW） and severe drought group（LW）.The results showed that 1 On the plant height， stem weight，root weight， leaf mass ratio and root mass ratio，there was no significant difference among treatment groups（P>0.05）；HW group was the largest with the leaf root ratio， specific leaf area and leaf area ratio. 2 With the increase of light intensity，the daily variation trend of G. parviflora of net photosynthetic rate for CK was rise-decline-rise，while for HW and LW first increased and then decreased. The light compensation point of CK was 9.07 μmol/cm2·s，which was the highest of all. The light saturation point of HW with the highest was 1 492.59 μmol/（cm2·s），while LW was the lowest was 79.25 μmol/（cm2·s）. The apparent quantum rate of the LW was the lowest. The maximum net photosynthetic rate of CK with the highest of all was 13.96 μmol/（cm2·s） under the maximum photosynthetic active radiation. 3 With soil moisture content decreasing， the net photosynthetic rate，stomatal conductance and transpiration rate for G. parviflora showed a trend of decline. The change of intercellular CO2 concentration was HW>CK>LW.

Key words： Galinsoga parviflora； soil moisture content； plant growth； photosynthetic characteristics

牛膝菊（Galinsoga parviflora）又名辣子草，为菊科牛膝菊属一年生草本植物。原产于南美洲，在我国归化，生于杂草地、荒坡、路旁、海港[1]。牛膝菊是一种入侵性很强的物种，国内外对牛膝菊都展开了深入的研究。目前主要的研究方面有化感作用[2-4]、种群分布特点[5，6]、种子萌发[7]、抗氧化酶系统[8]、危害及其防治[4]等。但土壤水分对牛膝菊生长和光合影响方面的研究还未见报道。土壤水分是植物生长不可或缺的生态因子，本研究旨在探讨不同土壤水分梯度下牛膝菊生长和光合的变化，为预测其潜在的分布范围和有效治理该入侵物种提供理论依据。

1 材料与方法

1.1 供试材料

牛膝菊种子采自沈阳大学校园（23°7′N，113°15′E），播种于装有混合土（V草皮土∶V营养土=1∶1）的塑料花盆内（直径19 cm，高16 cm），每盆8株。牛膝菊幼苗在……