黄波罗不同根序的解剖结构及其功能异质性

doi:10.3773/j.issn.1005-264x.2008.06.004

摘要/Abstract

摘要：

细根是树木吸收水分养分的主要器官, 其生长与周转对森林生产力及生态系统物质循环具有重要的影响。为了更好地认识细根的结构特征与功能及其在根序中的分布, 采用石蜡切片方法对黄波罗(Phellodendron amurense) 1~5级根解剖结构(直径、皮层组织、通道细胞数目、维管束发育和菌根侵染等)进行了观察统计。研究表明: 细根直径、维管束直径以及维管束在根中所占的比例随根序增加而增加。1~3级根皮层层数、皮层薄壁细胞直径相近, 但总体呈减少趋势, 部分4级根有少量残留的皮层, 而成熟的5级根已经没有表皮及皮层组织。1~3级根具有通道细胞, 菌丝侵染率均较高; 4、5级根无通道细胞, 也无菌丝侵染。1、2级根是初生根, 无木栓层; 4、5级根是次生根, 具有完整的木栓层; 3级根中既有初生根, 也有次生根, 并逐渐形成木栓层。说明随根序升高, 细根吸收能力减弱, 输导能力增加, 抵御环境胁迫的能力增加, 有利于延长寿命。根据解剖结构、直径和根序的关系, 将黄波罗前3级根中直径小于0.8 mm、未形成连续木栓形成层、具有通道细胞的根定义为细根。

关键词: 黄波罗, 细根, 根序, 解剖结构, 异质性

Abstract:

Aims Fine roots are the primary organs for nutrient and water uptake in trees. The growth and turnover of fine roots significantly influence productivity and matter cycles in forest ecosystems. Our objective was to elucidate the basic structure, function and allocation of fine roots in Phellodendron amurense.

Methods We made paraffin slices stained by safranin and fast green to observe anatomical structures (such as diameter, cortex, number of passage cells, development of vascular bundle, mycorrhizae of roots, etc.) of the first five orders of roots of P. amurense. Bright-light and fluorescence microscopes were used to observe and take photos.

Important findings Root diameter (R), vascular bundle diameter (V) and V/R increased as root order increased. The thickness and layers of cortex were similar in the first three orders. Few cortical cells were in fourth-order roots and almost none in fifth-order roots. There were higher mycorrhizae infections in the first three order roots than the last two orders, and the later had almost no fungi. Primary growth occurred in all first- and second-order roots, and secondary growth occurred in all fourth and fifth order roots. Some third-order roots had only primary growth, but some had secondary growth with inconsecutive phellogen. All results suggested that the ability of roots to absorb nutrients and water decreased but transport ability and longevity increased as root orders increased. According to the relationships among anatomical characteristics, diameters and root orders, the fine roots of P. amurense should be involved in the first three orders at most; these have passage cells but lack successive phellogen and have diameters less than 0.8 mm.

Key words: Phellodendron amurense, fine root, root order, anatomical structure, heterogeneity

卫星, 刘颖, 陈海波. 黄波罗不同根序的解剖结构及其功能异质性. 植物生态学报, 2008, 32(6): 1238-1247. DOI: 10.3773/j.issn.1005-264x.2008.06.004

WEI Xing, LIU Ying, CHEN Hai-Bo. ANATOMICAL AND FUNCTIONAL HETEROGENEITY AMONG DIFFERENT ROOT ORDERS OF PHELLODENDRON AMURENSE. Chinese Journal of Plant Ecology, 2008, 32(6): 1238-1247. DOI: 10.3773/j.issn.1005-264x.2008.06.004

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链接本文: https://www.plant-ecology.com/CN/10.3773/j.issn.1005-264x.2008.06.004

https://www.plant-ecology.com/CN/Y2008/V32/I6/1238

图/表 6

图1 黄波罗1~5级根维管束直径V、细根直径R及维/根比V/R

Fig. 1 The vascular bundle diameter (V), the root diameter (R) and V/R among the first five order roots of Phellodendron amurense

表1 黄波罗1~5级根直径及维管束直径最大值、最小值和变异系数

Table 1 The minimal and maximal diameters, the coefficients of variations of root and vascular bundle diameter among the first five orders roots of Phellodendron amurense

		根序 Root order
		1级 First order	2级 Second order	3级 Third order	4级 Fourth order	5级 Fifth order
平均细根直径 Mean root diameter	最小值到最大值 From Min. to Max. (mm)	0.38 ~ 0.73	0.47 ~ 0.62	0.47 ~ 0.78	0.79 ~ 1.59	1.95 ~ 2.43
平均细根直径 Mean root diameter	变异系数 CV (%)	16.12	9.62	14.53	20.11	6.91
维管束直径 Vascular bundle diameter	最小值到最大值 From Min. to Max. (mm)	0.08 ~ 0.19	0.11 ~ 0.22	0.12 ~ 0.38	0.63 ~ 1.37	1.69 ~ 2.07
维管束直径 Vascular bundle diameter	变异系数 CV (%)	21.86	18.71	33.65	23.83	6.72

图2 黄波罗1~5级根横切片(I -V) I: 1级根 The first order root II: 2级 The second order root III: 3级 The third order root IV: 4级 The fourth order root V: 5级 The fifth order root (1) 自然光下 Under bright light (2) 荧光下 Under fluorescence c: 皮层细胞 Cortical cell ep: 表皮 Epidermis ex: 外皮层 Exodermis pe: 周皮 Periderm pl: 木栓层 Phellem v: 维管束 Vascular bundle xl: 木质部 Xylem Bar=100 μm

Fig. 2 Transverse sections of the first to fifth order roots of Phellodendron amurense

图3~11 黄波罗细根皮层及中柱结构特征。 3. 黄波罗1级根表皮、外皮层及皮层薄壁细胞。4. 黄波罗1级根外皮层上通道细胞。5. 黄波罗1级根皮层薄壁细胞内侵染大量的菌丝。 6. 黄波罗1级根内形成的气腔。7. 黄波罗2级根内形成的气腔。 8. 黄波罗细根内皮层凯氏带(自然光)。9. 黄波罗细根内皮层凯氏带(荧光)。 10. 黄波罗2级根产生的新根。 11. 黄波罗3级根不连续木栓层 ac: 气腔 Air cavity c: 皮层细胞 Cortical cell cb: 凯氏带 Casparian band cp: 皮层薄壁细胞 Cotical parenchyma en: 内皮层 Endodermis ep: 表皮 Epidermis ex: 外皮层 Exodermis pc: 通道细胞 Passage cell m: 菌丝 Mycorrhizae pl: 木栓层 Phellem xl: 木质部 Xylem

Figs. 3-11 The cortex and stele characteristics of Phellodendron amurense fine roots. 3. The epidermis, exodermis and cortical parenchyma of the first order root of P. amurense. 4. Transverse section of the first order root of P. amurense, showing the passage cell in exodermis. 5. Transverse section of the first order root of P. amurense, showing lots of maccorizal in the cortical parenchyma. 6. The air cavity occurred in the first order roots of P. amurense. 7. The air cavity occurred in the second order roots of P. amurense. 8. The casparian band in endodermis of P. amurense under bright light. 9. The casparian band in endodermis of P. amurense under fluorescence. 10. The new root emerged from the second order root of P. amurense. 11. The inconsecutive phellem in the third order root of P. amurense

表2 黄波罗1~5级根部分解剖特征(平均值±标准误差)

Table 2 Anatomical characteristics of the first five order roots of Phellodendron amurense (mean±SE)

	根级 Root order
	1级 First order	2级 Second order	3级 Third order	4级 Fourth order	5级 Fifth order
皮层薄壁组织 Cortical parenchyma	+	+	+	有少部分Partially	-
皮层薄壁细胞直径 Diameter of cortical cells (μm)	177.74 ± 6.95	175.59 ± 5.83	176.04 ± 4.50	0	0
皮层层数 Cortex layers	9.94 ± 0.23	9.43 ± 0.17	9.13 ± 0.23	0	0
通道细胞数目 No. of passage cell	19.23 ± 1.67	20.54 ± 1.31	22.69 ± 1.92	0	0
菌丝侵染 Mycorrhizae infection	+	+	+	-	-
菌丝侵染度 The degree of mycorrhizae	2.34 ± 0.11	2.28 ± 0.07	1.88 ± 0.16	0	0
维管形成层 Vascular cambium	-	-	+	+	+
次生生长 Secondary growth	0	0	47%	100%	100%
木栓形成层 Phellogen	0	0	47%	100%	100%

表3 黄波罗1~5级根直径、菌根侵染度与解剖结构的相关性分析

Table 3 The correlation among root diameter, degree of micorrhizae and anatomical structures of the first five order roots of Phellodendron amurense

	细根 Fine roots
	1级 First order			2级 Second order			3级 Third order			4级 Fourth order			5级 Fifth order
	n	r	p	n	r	p	n	r	p	n	r	p	n	r	p
根直径×维管束直径 Root diameter × Vascular bundle diameter	20	0.874*	0.001	20	0.482*	0.043	20	0.882**	0.001	10	0.969**	0.001	10	0.991**	0.008
根直径×维/根 Root diameter × The ratio of vascular bundle to root diameter	20	0.229	0.334	20	0.03	0.906	20	0.782**	0.001	10	0.388	0.267	10	0.354	0.316
根直径×皮层薄壁细胞直径 Root diameter × Diameter of cotical parenchyma	20	0.955**	0.001	18	0.884**	0.011	19	0.627**	0.004	10	0	0	10	0	0
根直径×皮层层数 Root diameter × Cortex layers	15	0.616*	0.014	14	0.620*	0.018	14	0.433	0.122	10	0	0	10	0	0
根直径×通道细胞数目 Root diameter × Numbers of passage cell	20	0.733**	0.001	18	0.268	0.282	19	0.123	0.017	10	0	0	10	0	0
根直径×菌根侵染度 Root diameter × The degree of mycorrhizae	19	0.339	0.155	20	-0.016	0.951	19	-0.011	0.966	10	0	0	10	0	0
菌根侵染度×维管束直径 Degree of micorrhizae × Vascular bundle diameter	19	0.231	0.340	18	-0.309	0.213	19	-0.4	0.09
菌根侵染度×维/根 Degree of micorrhizae × The ratio of vascular bundle to root diameter	19	-0.074	0.762	18	-0.351	0.153	19	-0.547*	0.015
菌根侵染度×通道细胞数目 Degree of micorrhizae × Numbers of passage cell	19	-0.06	0.809	20	-0.179	0.449	19	-0.054	0.826
菌根侵染度×皮层薄壁细胞直径 Degree of micorrhizae × Diameter of cotical parenchyma	19	0.378	0.110	20	0.423	0.063	19	0.26	0.282
菌根侵染度×皮层层数 Degree of micorrhizae × Cortex layers	14	0.711**	0.004	14	-0.048	0.871	14	0.441	0.115

表3 黄波罗1~5级根直径、菌根侵染度与解剖结构的相关性分析

Table 3 The correlation among root diameter, degree of micorrhizae and anatomical structures of the first five order roots of Phellodendron amurense

	细根 Fine roots
	1级 First order			2级 Second order			3级 Third order			4级 Fourth order			5级 Fifth order
	n	r	p	n	r	p	n	r	p	n	r	p	n	r	p
根直径×维管束直径 Root diameter × Vascular bundle diameter	20	0.874*	0.001	20	0.482*	0.043	20	0.882**	0.001	10	0.969**	0.001	10	0.991**	0.008
根直径×维/根 Root diameter × The ratio of vascular bundle to root diameter	20	0.229	0.334	20	0.03	0.906	20	0.782**	0.001	10	0.388	0.267	10	0.354	0.316
根直径×皮层薄壁细胞直径 Root diameter × Diameter of cotical parenchyma	20	0.955**	0.001	18	0.884**	0.011	19	0.627**	0.004	10	0	0	10	0	0
根直径×皮层层数 Root diameter × Cortex layers	15	0.616*	0.014	14	0.620*	0.018	14	0.433	0.122	10	0	0	10	0	0
根直径×通道细胞数目 Root diameter × Numbers of passage cell	20	0.733**	0.001	18	0.268	0.282	19	0.123	0.017	10	0	0	10	0	0
根直径×菌根侵染度 Root diameter × The degree of mycorrhizae	19	0.339	0.155	20	-0.016	0.951	19	-0.011	0.966	10	0	0	10	0	0
菌根侵染度×维管束直径 Degree of micorrhizae × Vascular bundle diameter	19	0.231	0.340	18	-0.309	0.213	19	-0.4	0.09
菌根侵染度×维/根 Degree of micorrhizae × The ratio of vascular bundle to root diameter	19	-0.074	0.762	18	-0.351	0.153	19	-0.547*	0.015
菌根侵染度×通道细胞数目 Degree of micorrhizae × Numbers of passage cell	19	-0.06	0.809	20	-0.179	0.449	19	-0.054	0.826
菌根侵染度×皮层薄壁细胞直径 Degree of micorrhizae × Diameter of cotical parenchyma	19	0.378	0.110	20	0.423	0.063	19	0.26	0.282
菌根侵染度×皮层层数 Degree of micorrhizae × Cortex layers	14	0.711**	0.004	14	-0.048	0.871	14	0.441	0.115

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