全 文 :Journal of Forestry Research, 17(3): 247−251 (2006) 247
Anatomical adaptations of three species of Chinese
xerophytes (Zygophyllaceae)
YANG Shu-min1, FURUKAWA Ikuo2
1 Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing, 100091, P. R. China
2 Faculty of Agriculture, Tottori University, Koyama, Tottori 680-8553, Japan
Abstract: Secondary xylem characteristics and horizontal variations were described in three xerophytic species, Zygophyllum xanthoxylon,
Nitraria tangutorum, Tetraena mongolica of Zygophyllaceae native to western China. All the species have obvious growth ring boundaries
except sometimes discontinuous in T. mongolica and Z. xanthoxylum ring to semi-ring-porosity; simple perforation plate; alternate in-
tervessel pitting; non-septate fibres; paratracheal confluent axial parenchyma; helical thickenings and heterocellular rays. However the ves-
sel arrangement and quantitative features of vessels were different. Vessel elements tend to be shorter and narrower and more frequent in T.
mongolica than in other two species that are hardly different could lead to greater conductive safety. The variation of vessel element length
and fibre length along radial direction showed irregular tendency. There was significant difference in both fibre length and vessel element
length among-tree and within-tree. Furthermore, the relationships between anatomical features and adaptability to desert environments were
also discussed.
Keywords: Anatomical adaptations; Horizontal variations; Xerophytes; Zygophyllaceae,
CLC number: S781.1 Document code: A Article ID: 1007-662X(2006)03-0247-05
Introduction
Zygophyllaceae consists of shrubs and herbs, very rare trees
that have its main distribution in the eastern and the western
hemispheres on arid lands, particularly on saline deserts. Most
species of genera Nitraria, Zygophyllum and Tetraena are often
found in northwest China.
Nitraria is typical plant in desert with strong ability to resist
salinity and alkalinity, drought, wind and dust, and it can effi-
ciently to fix moving sands, decrease wind speed. Furthermore, it
is valuable for providing food, medicine and firewood. Zygo-
phyllum is often planted as a fodder, medicine and important
vegetation to control loss of water and erosion of soil. Tetraena
is endangered shrubs due to its difficult natural regeneration and
over-harvest as forage with higher combustibility. Particularly,
they have strong ecological adaptability and amazing ability to
fix moving sands and preserve soil and water in the arid and
semi-arid regions of China.
Previous studies on wood anatomy of other species in Zygo-
phyllaceae have mainly on general description (Schweingruber
1990). There is yet no detailed description of the wood of the
selected species. The purpose of this paper is to provide prelimi-
nary information of the wood anatomy of selected species and
discuss the relationship between anatomical characteristics of
secondary xylem and adaptability to arid climate. The informa-
tion obtained through this study will be useful for selecting and
introducing suitable species to control desert expansion.
Materials and methods
The study materials are Zygophyllum xanthoxylon (Bge.)
Biography: YANG Shu-min (1971), female, Ph. D. Lecture in the Research
Institute of Wood Industry, Chinese Academy of Forestry, Beijing, 100091, P.
R. China. E-mail: shangke620@hotmail.com
Received date: 2006-02-06; Accepted date: 2006-04-05
Responsible editor: Chai Ruihai
Maxim, Nitraria tangutorum Bobr. and Tetraena mongolica
Maxim. in Zygophyllaceae obtained from Wuhai City, China.
Five healthy trees of each species were felled and two discs
(2−3 cm thick) from each sample tree were taken at the height of
20-30cm above the ground. All stem pieces measuring of these
trees were roughly 0.5−2 cm in diameter. Some of the discs were
immediately fixed in formalin-acetic-alcohol (5:5:90 v/v).
Wood samples were softened in ethylene diamine (Carlquist
1982a), subsequently sectioned with a sliding microtome moving
on transverse, radial and tangential surfaces of the disks. Thin
sections were stained with safranine, dehydrated in a graded
alcohol series and mounted in Canada balsam for light micro-
scope examination. Small blocks exposing transverse, radial and
tangential surfaces were respectively prepared according to Ex-
ley et al. (1977) for scanning electron microscope (X-650, Hi-
tachi Ltd Tokyo, Japan) observations. Maceration was prepared
through soaking in Jeffreys solution and mounted in glyc-
erin-jelly. Quantitative data are based on 25 measurements of
vessel element length and 50 of fibre length. Terminology and
methodology follow the IAWA list of microscopic features for
hardwood identification(IAWA Committee 1989).
Results
General description of wood anatomy
Growth ring boundaries are generally distinct, sometimes dis-
continuous in T. mongolica and Z. xanthoxylon, marked by
thick-walled latewood fibres or marginal parenchyma band;
wood is somewhat ring to semi-ring porous; vessels arrange in
tangential bands or slightly dendritic pattern in N. tangutorum;
vessels are 31%−65% solitary, infrequently in tangential multi-
ples of 2−3 or small clusters, but vessels present high grouping
degree in Z. xanthoxylon; vessel frequency is 106−221·mm-2.
Outline of vessels is round, oval or slightly irregular in cross
section, with 31−49µm in tangential diameter; vessel element
length is 93−150µm long (Fig. 1-6).
Rays are uniseriate in T. mongolica, occasionally biseriate,
YANG Shu-min and FURUKAWA Ikuo 248
2−5-seriate in other two species, infrequently uniseriate (Fig.
7−9); ray height varies from 88−981µm and frequency is
4-10/mm; body ray cells are procumbent in T. mongolica and N.
tangutorum, square or upright, slightly procumbent in Z.
xanthoxylon (Fig. 10−12). Pits are shown on the tangential wall
and radial wall of ray cells, round, oval to elongate.
Intervessel pitting is alternate, some vestured; pit apertures are
round to oval, elongated, slit-like or partly coalescent, with
1.9−2.0 µm in diameter (Fig. 13, 14).
Perforation plate is simple in oblique to almost horizontal end
walls (Fig. 15).
Vessel walls are smooth or with distinct helical thickenings
mainly throughout narrow vessels or confined to the tails of wide
vessel elements (Fig. 15).
278−468 µm long nonseptate fibres, mainly thick-walled, pre-
sent with simple to minutely bordered; slit-like pits and bordered
pits showed on fibre tracheid in N. tangutorum (Fig. 16).
Axial parenchyma abundantly present, paratrcheal to scanty
paratracheal or marginal bands, fusiform parenchyma cells pre-
sent with 2−4 cells per parenchyma strand.
Gummy contents present in vessels in N. tangutorum, crystals
present in ray cell in N. tangutorum (Fig. 17); rays, vessel ele-
ment and axial parenchyma are storied and vessel wall surface is
covered with warts in N. tangutorum (Fig. 18).
Fig. 1−6 Light microscope photographs, Transverse section.
Fig 1, 2 Tetraena mongolica. Fig.1 growth ring boundaries are distinct, occasionally continuous; Fig. 2 Vessels are solitary or in tangential multiples.
Fig. 3, 4 Zygophyllum xanthoxylon. Fig. 3. Wood is semi-ring porous with distant growth ring boundaries, occasionally continuous. Fig.4 Growth ring boundaries
were marked by axial parenchyma bands.
Fig. 5, 6 Nitraria tangutorum. Fig. 5 Vessels are arranged in tangential to seemingly dendritic pattern. Fig. 6 axial parenchyma abundantly present, paratracheal or
marginal bands.
Journal of Forestry Research, 17(3): 247−251 (2006) 249
Fig. 7−12 Light microscope photographs,
Fig. 7−9, tangential longitudinal section. Vessel elements, axial parenchyma, rays are storied to irregularly storied. Fig. 7 Tetraena mongolica, rays are uniseriate,
occasionally biseriate. Fig. 8 Zygophyllum xanthoxylon, rays 2-5-seriate, infrequently uniseriate. Fig. 9 Nitraria tangutorum, 2-5-seriate rays.
Fig. 10−12, radial longitudinal section. Fig. 10 Tetraena mongolica, Body rays were composed of procumbent cells. Fig. 11 Zygophyllum xanthoxylon, Heterocel-
lular rays are composed of procumbent, square or upright cells mixed. Fig. 12 Nitraria tangutorum, ray cells composed of procumbent cells with marginal square
cells.
Ecological wood anatomy
From the quantitative features (Table 1) and from the horizon-
tal variations according to their length (Fig. 19), it is clear that
the vessel element length and tangential vessel diameter are very
small in three species, less than 150 and 50µm, respectively, in
agreement with earlier observations in other xerophytes (IAWA
Committee 1989). Among three species, T. mongolica has the
larger vessel frequency, shorter and narrower vessel element than
other two species, which improves safety for hydraulic conduc-
tion.
Vessel element length and fibre length were plotted from pith
to bark on the basis of the measurement of samples taken at each
ring. The results of horizontal variation with ring number were
shown in Fig. 19. Both the vessel element length and fibre length
within one tree are more or less constant, and showed irregularly
increasing or decreasing curves in T. mongolica and Z.
xanthoxylon. While the length of the vessel element and fibre
slightly decreased with the number of the ring from the pith in N.
tangutorum
Statistically, there was significant difference for fibre length
and vessel element length among species and within species
(Table 2). The longest and shortest average fibre lengths were
468 and 278 µm respectively. The longest fibres were observed
in the species of Z. xanthoxylum, whereas the shortest fibres were
found in the species of T. mongolica.
YANG Shu-min and FURUKAWA Ikuo 250
Table 1 Quantitative anatomical features of three species in Zygo-
phyllaceae
Index
Nitraria
tangutorum
Zygophyllum
xanthoxylon
Tetraena
mongolica
Vessel number per mm2 106(60-132) 110(80-172) 221(104-308)
Tangential vessel diameter (µm) 42(21-81) 49(18-86) 31(16-59)
Vessel element length (µm) 150(86-214) 138(61-226) 93(21-156)
Solitary vessels (%) 31(15-40) 65(43-82) 38(25-54)
Fiber length (µm) 404(250-578) 468(105-732) 278(82-417)
Vulnerability index 0.40 0.45 0.14
Mesomorphy index 59.4 61.5 13.0
Intervessel pit diameter (µm) 1.9(1.5-2.3) 2.0(1.4-2.9) 1.9(1.4-2.3)
Ray height (µm) 521(240-920) 981(340-3000) 88(40-210)
Number of rays per mm 8(7-9) 4(3-5) 10(7-14)
Table 2 Analysis of variance of fibre length and vessel element length
of three species
Vessel element length
(F Value)
Fibre length
(F Value)
Among species 197.92** 128.49**
Within species (age)
Nitraria tangutorum 3.25** 34.06**
Zygophyllum xanthoxylon 2.09** 3.95**
Tetraena mongolica 2.74** 11.56**
** Significant at 5% level; ns , not significant
Fig. 19. Variations in vessel element length and fibre length of three
species of Zygophyllaceae
Discussion
The secondary xylem of the three species can be distinguished
by the qualitative and quantitative indices. These species grow in
habitats subject to high water stress and the wood anatomical
features and leaf show adaptations correlated to environmental
extremes. Leaf surface reduction with thick cuticles, photosyn-
0
50
100
150
200
0 5 10 15 20
Distance from pith to bark (mm)
V
es
se
l e
le
m
en
t l
en
gt
h
(µ
m
)
Nitraria tangutorum
Zygophyllum xanthoxylon
Tetraena mongolica
0
100
200
300
400
500
600
0 5 10 15 20
Distance from pith to bark (mm)
Fi
br
e
le
ng
th
(µ
m
)
Nitraria tangutorum
Zygophyllum xanthoxylon
Tetraena mongolica
Fig.13−18, Scanning electronic microscope micrographs
Fig. 13. Tetraena mongolica, alternate intervessel pitting viewed
from outer surface (left) and from lumen side (right);
Fig. 14 Zygophyllum xanthoxylon, intervessel pitting is alternate
with slit-like inner pit apertures.
Fig. 15 Nitraria tangutorum, helical thickenings throughout the
small vessel walls; perforation plate is simple.
Fig.16 Nitraria tangutorum, very thick-walled fibre. Fig. 17 Ni-
traria tangutorum, rhomboidal crystals present in ray cells.
Fig.18 Nitraria tangutorum, warts present in vessel walls.
Journal of Forestry Research, 17(3): 247−251 (2006) 251
thesizing by green stems and cutinization of the outer walls in
leaf epidermis enables plants to have the ability to withstand dry
climatic periods (Villagra et al. 1997; Lindorf 1997). Wood or
secondary xylem provides a complex tissue for water transport,
mechnical strength, and for metabolic processes such as storage
and mobilization of reserve carbohydrates and lipids (Baas 1986;
Carlquist 1988; Zimmermann 1977, 1983). Ecological and evo-
lutionary trends in vessel diameter, perforation plate type, vessel
frequency, vessel member length, total vessel length, and fibre
type have all been discussed in terms of their input to the safety
and efficiency of water transport (Zimmermann et al. 1971 &
Baas 1986). In general, the tendencies are for vessel members to
become shorter and narrower as the aridity increases to prevent
collapse of vessels under high negative pressures and vessels
towards grouping in arid environments (Carlquist 1966, 1985;
Baas et al. 1986; Zhong et al. 1992; Fahn et al. 1986& Lindorf
1994). Vessels mainly solitary or few vessel grouping, narrow
and numerous could lead to greater conductive safety because it
renders the inactivation of any vessel less harmful by enabling
the water transport to be transferred to an adjacent vessel (Car-
lquist 1984). This tendency agreed with general xeric character
that was observed in other families (Bass 1988, Carlquist 1984,
1988). Vessel elements tend to be shorter and narrower and more
frequent in T. mongolica than in other two species (Table 1 and
Fig. 19). It indicates T. mongolica is more xeric.
Vulnerability (mean vessel diameter divided by the mean
number of vessels per sq. mm) and mesomorphy (vulnerability
multiplied by mean vessel element length) are proposed by Car-
lquist (1977, 1992) to express the conductive safety and effi-
ciency within xylem part. Larger indices (V>1, M>800) indicate
more mesomorphic. Table 1 shows that T. mongolica is more
xeromorphic than other two species. Both efficiency or maximal
conductivity and safety are strongly related to vessel diameter
and vessel frequency. Increased vessel diameter increases effi-
ciency of water conduction dramatically, but at the same time it
decreases safety. However, ring-porosity and presence of differ-
ent vessel size classes in general are of importance for the com-
bined efficiency and safety of xylem sap transport at different
times in or throughout the growing seasons (Baas et al. 1987).
The gradually decreased vessel diameter from earlywood to
latewood allows for optimal transport efficiency by wide vessels
and provides great conductive safety through the narrow late-
wood vessels (Zimmermann 1982; Baas et al. 1988 & Woodcock
1994).
Apart from these quantitative characters, the qualitative char-
acters show ecological correlations. The growth ring boundaries
in T. mongolica and Z. xanthoxylum are discontinous maybe due
to the irregular change of seasonal climate. Some narrow vessels
in three species have coarse helical thickenings, which increases
cell wall strength to withstand high pressures or enlarges wall
surface to promote water bonding to the surface (Carlquist 1975,
1982). In this study, all species show helical thickenings, to-
gether with vessel groups and tracheids, which are associated
with greater conductive safety in arid environments.
Carlquist and Hoekman (1985) point out there are many other
alternative strategies for a plant to survive in water deficit condi-
tions except wood features. Wood structure should be considered
as one of the xeromorphic characteristics.
The difference in range of fibre length is attribute to differ-
ences in age of wood and to the diverse environmental conditions
in this study area. The wood fibres are thick-walled and have
narrow lumina with varied shape and size. Some of them are
straight and spindle-shaped while others have undulated walls.
Their length including sharp points shows significant variation.
From this study, vessel element length and fibre length are short
due to its short fusiform initials, in agreement with the results
from Carlquist (1988).
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Chinese Abstracts 3
厅, 沈阳 110014),代力民(中国科学院沈阳应用生态研究所,
沈阳 110016),王庆礼(中国科学院沈阳分院,沈阳 110005)
////Journal of Forestry Research.–2006, 17(3): 216-220.
基于 28 个 20 m×90 m 样地的调查数据,利用
Lotka-Volterra模型,本文分析了长白山北坡阔叶红松 (Pinus
koraiensis) 林和云冷杉林(也叫暗针叶林)群落交错区优势
树种之间的竞争及动态。结果显示:在自然条件下,群落将
向两个方向分化,一是以云杉(Picea jezoensis and P. koraiensis)
和冷杉(Abies nephrolepis)为优势的群落,并在达到平衡时冷
杉占绝对优势(相对优势度的 77.1%);另一种是以红松或云
冷杉和阔叶树占绝对优势的针阔混交林,并在达到平衡时,
阔叶树在阔叶红松林中占相对优势度的 50%,在云冷杉-阔
叶林类型中占 66%。同时,本研究说明:(1)阔叶红松林和
云冷杉林都是长白山气候顶极群落;(2)交错区具有过渡性
质;(3)森林群落的分化结果说明演替的方向受局部生境的
影响。图 1表 3参 24。
关键词:竞争和动态;Lotka-Volterra 模型;森林群落交错区;
长白山
CLC number: S718.542 Document code: A
Article ID: 1007−662X(2006)03−0216–05
06–03–011
森林草原过渡带中沙地云杉幼苗在林窗中的环境梯度变化/
邹春静(上海市城市化生态过程与生态恢复重点实验室;华东
师范大学生命科学学院,上海200062),张超,马永亮(华东师
范大学资源与环境科学学院,上海200062),徐文铎(中国科学
院沈阳应用生态研究所,沈阳110016)//Journal of Forestry
Reseach.–2006, 17(3): 221–225.
在我国内蒙古自治区森林草原过渡带中,从林窗内到周
围环境进行沙地云杉(Picea mongolica)幼苗的调查以阐明
其梯度变化。在沙地森林区,选择了一个形成年龄长达 30年
的大林窗,从林窗中央向周围森林作 2 个 5m 宽的样带,对
沙地云杉幼苗动态进行了监测。幼苗距离林窗中心越远,个
体越高,数量也越多。在林窗内,有很多幼苗,但是大多数
的幼苗在它们长大之前就死亡了。相对于林木高度的动态变
化,幼苗的死亡率在样带中的分布基本上有着相似的规律。
沿着森林的边缘,幼苗的生长可能由于林窗中边缘光线渗透
而得到暂时的提高。文中还讨论了自然森林的更新动态。结
果表明在沙地云杉林里林窗干扰带能产生一个非均质的环境
促进物种的更新,从而决定了该森林是一个多年龄层次的森
林类型。图 6参 37。
关键词:沙地云杉;沙地森林;幼苗生长;林窗;
光合有效辐射;土壤湿度
CLC number: S753.3 Document code: A
Article ID: 1007−662X(2006)03−0221–05
06–03–012
林豆复合生态系统土壤理化性质的研究/范阿南(中国科学院
沈沈阳应用生态研究所,沈阳 110016; 中国科学院研究生院,
北京 100049), 陈祥伟(东北林业大学林学院,哈尔滨 150040),
李志敏(辽宁省喀左县林业局,朝阳 122300)//Journal of For-
estry Reseach.–2006, 17(3): 226–230.
本文对混种大豆的落叶松-大豆、水曲柳-大豆复合生态系
统土壤理化性质进行研究。结果表明,在一个生长季内混种
后的土壤物理性质得到了改善。落叶松-大豆与水曲柳-大豆复
合生态系统的土壤容重为 1.112g/cm3 和 1.058g/cm3均低于相
对应的纯林;混种大豆后土壤总孔隙度增加。两种林-豆复合
生态系统土壤有机质分别比对应纯林高 1.77倍和 1.09倍;落
叶松-大豆复合生态系统全氮和水解氮含量分别高于落叶松
纯林 4.2%和 53.0/%,水曲柳-大豆复合生态系统全氮和水解
氮含量分别高于水曲柳纯林 75.5%和 3.3%;混种大豆后全磷
含量降低,而有效磷含量则增加;落叶松-大豆复合生态系统
全钾和有效钾比落叶松纯林高 0.6%和 17.5%,水曲柳-大豆复
合生态系统全钾和有效钾分别比水曲柳纯林高 56.4%和
21.8%。图 1表 3参 27。
关键词:林豆复合生态系统;土壤养分含量;土壤理化性质;
落叶松-大豆复合生态系统;水曲柳-大豆复合生态系
统
CLC numbers: S714.5 Document Code: A
Article ID: 1007−662X(2006)03−0226–05
06–03–013
大兴安岭北坡火后紫貂冬季生境恢复研究/解伏菊(中国科学
院沈阳应用生态研究所 沈阳110016;中国科学院研究生院
北京 100049), 李秀珍, 肖笃宁(中国科学院沈阳应用生态
研究所 沈阳 110016),贺红仕(中国科学院沈阳应用生态研
究所 沈阳 110016;School of Natural Resources, University of
Missouri-Columbia, Columbia, MO 65211-7270, USA)//Journal
of Forestry Research .-2006, 17(3): 231−237
由自然和人为原因引起的生境丧失与生境破碎化已严重
影响到野生动物的生存。大兴安岭北坡是国家一级保护动物
紫貂(Martes zibellina)的主要分布区,1987年发生在这里的特
大森林火灾造成了森林景观的严重破碎化,紫貂的生存面临
极大的威胁。本文的研究目的是为了确定火灾 13年后,紫貂
冬季生境的恢复程度。首先根据紫貂对冬季生境的喜好选取
对其生存影响较大的生态因子,结合数字化林相图,利用地
理信息系统软件 ArcGIS编制火烧前后的生境适宜性类型图。
然后选取相关的景观格局指标,对火灾烧前后的生境格局进
行对比分析。结果显示:尽管火后采取了一系列的森林恢复
措施,但紫貂冬季适宜生境仍有大幅度减少,特别是中等适
宜生境类型减少最为明显。适宜生境破碎化加剧,隔离度增
加。适宜生境斑块的形状趋于简单,软边界比重有所增加。
以上结果表明,与火前相比,紫貂生境明显恶化,需要较长
的时间恢复。图 4表 5参 41。
关键词:生境适宜性;生境丧失;生境破碎化;边缘效应;
生境恢复
ClC number: Q958 Document code: A
Article ID: 1007-662X(2006)03-0231-07
06–03–014
农杆菌介导高羊茅基因转化体系的建立/钱海丰(浙江工业大
学生物与环境工程学院,杭州 310014),Shaukat Ali(浙江工
业大学生物与环境工程学院,杭州 310014;巴基斯坦农业研
究中心,伊斯兰堡),洪亮,许皓(浙江工业大学生物与环境
工程学院,杭州 310014)//Journal of Forestry Research.–2006,
17(3): 238–242.
以高羊茅 (Festuca arundinacea Schrebb )品系宾哥
(Bingo)为材料,建立了农杆菌介导的基因转化方法。高羊
茅种子在9mg L-1 2,4-D作用下,获得胚性愈伤组织。愈伤组
织经农杆菌侵染,在30和 50 mg L-1的潮霉素浓度梯度下筛
选,得抗性愈伤组织。组织化学染色法证实,uidA基因在抗
性愈伤组织中表达;抗性愈伤组织在分化培养基中分化得到
转基因植株。PCR、Southern杂交法证实外源基因已导入到高
羊茅植株中。图5参37。