Analyzing leaf anatomical structure of dominant species Stipa purpurea adapting to alpine and drought environment at Qingzang Plateau

doi:10.17521/cjpe.2020.0322

Abstract

Abstract:

Aims The anatomical structure of plant leaves could be a direct reflection of the plant’s mechanism of response and adaptation to climate change. The distribution of alpine steppe has increased due to climatic warming over the Qingzang Plateau.Stipa purpurea is the dominant species of alpine steppe. However, few studies have been conducted on the adaptation mechanisms of alpine steppe plants. In this study, we analyzed the characteristics of leaf anatomical structure among different populations of S. purpurea and the relationship between these characteristics and climatic factors over the Qingzang Plateau. The ultimate aim was to identify the mechanism by which S. purpurea acclimatizes to alpine environments.
Methods Leaves of S. purpurea were collected from eight sites on the Qingzang Plateau and fixed using FAA fixative solution. Then, the leaves were paraffin wax sectioned and double-stained. Samples were then observed with a microscope and photographed with a digital camera. The area and thickness of leaf anatomical structure were measured with the soft (Image-pro plus 6.0).
Important findings Leaves of S. purpurea generally had thick cuticles, which were able to reduce water loss and radiation exposure. From the results of one-way analysis of variance, there were significant differences among the eight populations in collenchymatous cell thickness, vessel diameter, bundle catheter cavity area/bundle of the main vascular area, and vascular area/leaf cross-sectional area, which were beneficial characteristics for S. purpurea in adapting to the local environment. The characteristics of leaf anatomical structure were significantly correlated with environmental factors via Pearson’s analysis and cluster analysis. The results from principal component analysis and redundancy analysis showed that the anatomical structures in arid regions were mainly affected by annual evaporation, and those in semi-humid regions were mainly affected by the average precipitation humidity index and annual precipitation/annual evaporation during the growing season. In conclusion, to adapt to the alpine and arid environment,S. purpurea has reduced water loss by simultaneously increasing its collenchymatous cell thickness and water-conducting tissue area (vessel diameter, bundle catheter cavity area/bundle of main vascular area, and vascular bundle area/leaf cross-sectional area).

Key words: alpine steppe, Stipa purpurea, leaf anatomical structure, climate factor, adapted mechanism

WU Jian-Bo, WANG Xiao-Dan. Analyzing leaf anatomical structure of dominant species Stipa purpurea adapting to alpine and drought environment at Qingzang Plateau[J]. Chin J Plant Ecol, 2021, 45(3): 265-273.

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URL: https://www.plant-ecology.com/EN/10.17521/cjpe.2020.0322

https://www.plant-ecology.com/EN/Y2021/V45/I3/265

Figures/Tables 9

References 29

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样点 Site	地理位置 Geographic position	海拔 Altitude (m)	草原类型 Grass type	优势种 Dominant species	≥0 ℃积温 ≥0 °C accumulated temperature (℃·d)	年降水量 Mean annual precipitation (MAP, mm)	年平均气温 Mean annual air temperature (MAT, ℃)	年蒸发量 Mean annual evaporation (mm)
安多 Amdo	32.24° N 91.61° E	4 746	高寒草甸 Alpine meadow	高山嵩草 Kobresia pygmaea	869	439	-2.8	1 725
当雄 Damxung	32.25° N 90.66° E	4 228	高寒草原化草甸 Alpine steppe meadow	高山嵩草 K. pygmaea 紫花针茅 Stipa purpurea	1 536	456	1.3	1 710
五道梁 Wudaoliang	32.26° N 90.19° E	4 576	高寒草原 Alpine steppe	紫花针茅 S. purpurea	683	259	-5.1	1 421
班戈 Baingoin	31.36° N 90.45° E	4 682	高寒草原 Alpine steppe	紫花针茅 S. purpurea	1 048	321	-0.8	1 994
尼玛 Nyima	31.78° N 87.28° E	4 554	高寒草原 Alpine steppe	紫花针茅 S. purpurea	1 453	200	-0.4	2 200
改则 Gêrzê	31.20° N 84.53° E	4 477	高寒草原 Alpine steppe	紫花针茅 S. purpurea	1 453	170	0.1	2 255
革吉 Gê’gyai	31.20° N 81.56° E	4 502	高寒草原 Alpine steppe	紫花针茅 S. purpurea	1 566	120	0.4	2 420
噶尔 Gar	32.46° N 80.10° E	4 300	高寒荒漠 Alpine dessert	紫花针茅 S. purpurea	1 573	72	0.7	2 696

样点 Site	地理位置 Geographic position	海拔 Altitude (m)	草原类型 Grass type	优势种 Dominant species	≥0 ℃积温 ≥0 °C accumulated temperature (℃·d)	年降水量 Mean annual precipitation (MAP, mm)	年平均气温 Mean annual air temperature (MAT, ℃)	年蒸发量 Mean annual evaporation (mm)
安多 Amdo	32.24° N 91.61° E	4 746	高寒草甸 Alpine meadow	高山嵩草 Kobresia pygmaea	869	439	-2.8	1 725
当雄 Damxung	32.25° N 90.66° E	4 228	高寒草原化草甸 Alpine steppe meadow	高山嵩草 K. pygmaea 紫花针茅 Stipa purpurea	1 536	456	1.3	1 710
五道梁 Wudaoliang	32.26° N 90.19° E	4 576	高寒草原 Alpine steppe	紫花针茅 S. purpurea	683	259	-5.1	1 421
班戈 Baingoin	31.36° N 90.45° E	4 682	高寒草原 Alpine steppe	紫花针茅 S. purpurea	1 048	321	-0.8	1 994
尼玛 Nyima	31.78° N 87.28° E	4 554	高寒草原 Alpine steppe	紫花针茅 S. purpurea	1 453	200	-0.4	2 200
改则 Gêrzê	31.20° N 84.53° E	4 477	高寒草原 Alpine steppe	紫花针茅 S. purpurea	1 453	170	0.1	2 255
革吉 Gê’gyai	31.20° N 81.56° E	4 502	高寒草原 Alpine steppe	紫花针茅 S. purpurea	1 566	120	0.4	2 420
噶尔 Gar	32.46° N 80.10° E	4 300	高寒荒漠 Alpine dessert	紫花针茅 S. purpurea	1 573	72	0.7	2 696

	高寒草甸 Alpine meadow		高寒草原 Alpine steppe
	安多 Amdo	当雄 Damxung	五道梁 Wudaoliang	班戈 Baingoin	尼玛 Nyima	改则 Gêrzê	革吉 Gê’gyai	噶尔 Gar
角质层厚度 Cuticle thickness (μm)	4.75 ± 0.95	5.22 ± 0.46	5.85 ± 0.38	5.51 ± 0.74	4.36 ± 0.15	5.18 ± 0.40	4.99 ± 0.81	5.25 ± 0.62
外表皮厚度 Outer epidermal thickness (μm)	12.16 ± 2.31 ^a	8.93 ± 0.40 ^b	9.51 ± 0.34 ^b	7.63 ± 0.51 ^b	9.76 ± 1.53 ^b	7.36 ± 0.80 ^b	8.89 ± 0.59 ^b	8.08 ± 0.71 ^b
内表皮厚度 Inner epidermal thickness (μm)	18.82 ± 3.07 ^a	7.80 ± 0.45 ^b	6.95 ± 0.33 ^b	5.46 ± 0.33 ^b	6.35 ± 0.45 ^b	6.13 ± 0.58 ^b	7.83 ± 0.77 ^b	8.49 ± 1.00 ^b
厚角细胞厚度 Collenchymatous cell thickness (μm)	0	5.16 ± 0.82 ^b	4.92 ± 0.22 ^b	9.18 ± 2.12 ^a	13.32 ± 1.35 ^a	11.67 ± 1.72 ^a	10.66 ± 0.76 ^a	13.97 ± 0.78 ^a
气孔宽度 Stoma width (μm)	28.33 ± 8.82 ^a	12.42 ± 1.73 ^bc	10.06 ± 0.60 ^c	9.97 ± 1.22 ^c	12.35 ± 0.50 ^bc	13.55 ± 1.14 ^bc	15.37 ± 1.45 ^b	15.62 ± 1.05 ^b
叶片厚度 Leaf thickness (μm)	269.89 ± 19.67 ^a	179.12 ± 16.49 ^c	170.74 ± 2.60 ^c	173.46 ± 2.69 ^c	196.55 ± 11.10^bc	190.09 ± 19.18 ^bc	246.28 ± 31.81 ^b	212.33 ± 2.64 ^b
导管直径 Vessel diameter (μm)	16.04 ± 2.09 ^a	12.13 ± 1.13 ^b	9.73 ± 0.42 ^c	12.83 ± 1.36 ^b	11.82 ± 1.13 ^b	12.73 ± 1.34 ^b	21.15 ± 2.84 ^a	18.36 ± 2.23 ^a
主脉导管腔面积/主脉维管束面积 Catheter cavity area/area of main vascular bundle	0.11 ± 0.00 ^b	0.11 ± 0.01 ^b	0.07 ± 0.00 ^c	0.11 ± 0.02 ^b	0.11 ± 0.00 ^b	0.15 ± 0.02 ^a	0.16 ± 0.03 ^a	0.16 ± 0.02 ^a
维管束面积/叶横切面积Vascular area/leaf cross sectional area	0.04 ± 0.01 ^b	0.05 ± 0.01 ^b	0.07 ± 0.01 ^a	0.08 ± 0.01 ^a	0.07 ± 0.01 ^a	0.08 ± 0.01 ^a	0.08 ± 0.01 ^a	0.08 ± 0.01 ^a

	高寒草甸 Alpine meadow		高寒草原 Alpine steppe
	安多 Amdo	当雄 Damxung	五道梁 Wudaoliang	班戈 Baingoin	尼玛 Nyima	改则 Gêrzê	革吉 Gê’gyai	噶尔 Gar
角质层厚度 Cuticle thickness (μm)	4.75 ± 0.95	5.22 ± 0.46	5.85 ± 0.38	5.51 ± 0.74	4.36 ± 0.15	5.18 ± 0.40	4.99 ± 0.81	5.25 ± 0.62
外表皮厚度 Outer epidermal thickness (μm)	12.16 ± 2.31 ^a	8.93 ± 0.40 ^b	9.51 ± 0.34 ^b	7.63 ± 0.51 ^b	9.76 ± 1.53 ^b	7.36 ± 0.80 ^b	8.89 ± 0.59 ^b	8.08 ± 0.71 ^b
内表皮厚度 Inner epidermal thickness (μm)	18.82 ± 3.07 ^a	7.80 ± 0.45 ^b	6.95 ± 0.33 ^b	5.46 ± 0.33 ^b	6.35 ± 0.45 ^b	6.13 ± 0.58 ^b	7.83 ± 0.77 ^b	8.49 ± 1.00 ^b
厚角细胞厚度 Collenchymatous cell thickness (μm)	0	5.16 ± 0.82 ^b	4.92 ± 0.22 ^b	9.18 ± 2.12 ^a	13.32 ± 1.35 ^a	11.67 ± 1.72 ^a	10.66 ± 0.76 ^a	13.97 ± 0.78 ^a
气孔宽度 Stoma width (μm)	28.33 ± 8.82 ^a	12.42 ± 1.73 ^bc	10.06 ± 0.60 ^c	9.97 ± 1.22 ^c	12.35 ± 0.50 ^bc	13.55 ± 1.14 ^bc	15.37 ± 1.45 ^b	15.62 ± 1.05 ^b
叶片厚度 Leaf thickness (μm)	269.89 ± 19.67 ^a	179.12 ± 16.49 ^c	170.74 ± 2.60 ^c	173.46 ± 2.69 ^c	196.55 ± 11.10^bc	190.09 ± 19.18 ^bc	246.28 ± 31.81 ^b	212.33 ± 2.64 ^b
导管直径 Vessel diameter (μm)	16.04 ± 2.09 ^a	12.13 ± 1.13 ^b	9.73 ± 0.42 ^c	12.83 ± 1.36 ^b	11.82 ± 1.13 ^b	12.73 ± 1.34 ^b	21.15 ± 2.84 ^a	18.36 ± 2.23 ^a
主脉导管腔面积/主脉维管束面积 Catheter cavity area/area of main vascular bundle	0.11 ± 0.00 ^b	0.11 ± 0.01 ^b	0.07 ± 0.00 ^c	0.11 ± 0.02 ^b	0.11 ± 0.00 ^b	0.15 ± 0.02 ^a	0.16 ± 0.03 ^a	0.16 ± 0.02 ^a
维管束面积/叶横切面积Vascular area/leaf cross sectional area	0.04 ± 0.01 ^b	0.05 ± 0.01 ^b	0.07 ± 0.01 ^a	0.08 ± 0.01 ^a	0.07 ± 0.01 ^a	0.08 ± 0.01 ^a	0.08 ± 0.01 ^a	0.08 ± 0.01 ^a

	外表皮厚度 Outer epidermal thickness	内表皮厚度 Inner epidermal thickness	角质层厚度 Cuticle thickness	气孔宽度 Stoma width	叶片厚度 Leaf thickness	导管直径 Cavities diameter	厚角细胞厚度 Collenchymatous cell thickness	主脉导管腔面积/ 主脉维管束面积 Catheter cavity area/area of main vascular bundle	维管束面积/ 叶横切面积 Vascular area/leaf cross sectional area
年降水量 Mean annual precipitation (mm)	0.58	0.42	0.30	0.21	0.01	-0.55	-0.78^*	-0.87^**	-0.61
年平均气温 Mean annual air temperature (℃)	-0.34	-0.39	0.24	-0.31	-0.12	0.15	0.50	0.21	0.77^*
≥0 ℃积温 ≥0 °C accumulated temperature	0.11	0.29	-0.56	0.50	0.56	0.64	0.34	0.67	0.33
年蒸发量 Mean annual evaporation (mm)	-0.43	-0.26	-0.21	-0.05	0.16	0.61	0.76^*	0.79^*	0.76^*
年降水量/年蒸发量 Mean annual precipitation/mean annual evaporation	0.59	0.44	0.32	0.21	0.00	-0.55	-0.83^*	-0.87^**	-0.71^*
湿润指数 Humidity index	0.29	0.07	0.56	-0.18	-0.31	-0.69	-0.65	-0.91^**	-0.50
生长季平均气温 Mean air temperature during growing season	-0.50	-0.39	0.19	-0.24	-0.01	0.51	0.57	0.64	0.81^*
生长季降水量 Mean precipitation during growing season	0.52	0.28	0.05	0.10	-0.16	-0.75^*	-0.51	-0.90^**	-0.53
7月平均气温 Average air temperature at July	-0.42	-0.27	0.07	-0.10	0.12	0.59	0.55	0.70	0.79^*
7月降水量 Mean precipitation at July	0.50	0.28	0.05	0.11	-0.15	-0.73^*	-0.48	-0.87^**	-0.47