不同水分胁迫下的春小麦叶片气体交换参数和水分利用效率研究

doi:10.13866/j.azr.2021.03.24

摘要/Abstract

摘要：

叶片气体交换参数是作物产量形成的生理基础,其中光合速率和蒸腾速率决定了叶片水分利用效率,对作物抗旱节水研究具有重要意义。在定西和武威两个试验站进行春小麦盆栽水分模拟试验,设置对照（CK）、持续干旱（WS）、中旱（40%FC）和重旱（30%FC）4组处理,分析不同水分条件下春小麦叶片气体交换参数和水分利用效率（WUE_inst）的变化特点及其相关特征。结果表明：（1）持续干旱胁迫下,春小麦的土壤日耗水量、光合速率、蒸腾速率和气孔导度均呈先快后慢的下降趋势,达到中旱和重旱水平时相比CK分别减小了71%和76%、39%和60%、57%和66%、60%和77%,受影响程度为：气孔导度>蒸腾速率>光合速率,胞间CO₂浓度在轻旱-中旱时下降,中旱后期降幅达33%,之后呈上升趋势,WUE_inst在轻旱-中旱阶段上升,中旱后期时增加41%,之后下降,相比于CK,轻-重度胁迫会提高WUE_inst,极度干旱则使之降低;（2）当水分胁迫维持在中旱或重旱水平时,以上各指标均会维持在持续干旱达到相同干旱等级时对应的值附近,且中旱时值均高于重旱时的数值（P<0.05）;（3）在持续干旱胁迫的轻旱-中旱阶段,净光合速率和蒸腾速率互为主导影响因子,而在持续干旱胁迫之后的阶段,以及胁迫维持在中旱或重旱情形下,两者的主导因子均为气孔导度,WUE_inst在水分充足—持续干旱胁迫时均以蒸腾速率为主导因子,而当胁迫维持在中旱或重旱时其受叶片气体交换参数的调控作用不明显。本研究结果可为作物在不同干旱阶段和情形下采取适当措施进行抗旱节水提供参考依据。

关键词: 春小麦, 水分胁迫, 光合参数, 气孔导度, 水分利用效率

Abstract:

Leaf gas exchange parameters are the physiological basis of crop yield. Among these parameters, the photosynthetic and transpiration rates play a decisive role in leaf water use efficiency. Therefore, they are essential to research on crop drought resistance and water conservation. Potted water simulation experiments were conducted in spring wheat at Dingxi and Wuwei stations. Four group of treatments, including the control (CK), continuous drought stress (WS), moderate drought stress (40%FC), and severe drought stress (30%FC) treatments, were established to analyze the response characteristics and related characteristics of the gas exchange parameters and water use efficiency (WUE_inst) of spring wheat leaves under different levels of water stress. Under continuous drought stress, the daily soil water consumption, photosynthetic rate, transpiration rate, and stomatal conductance of spring wheat all showed an initially rapid and then slow downward trend. When the stress reached moderate and severe drought, these parameters were decreased by 71% and 76%, 39% and 60%, 57% and 66%, and 60% and 77%, respectively. The extent of reduction was stomatal conductance>transpiration rate>photosynthetic rate. The intercellular CO₂ concentration decreased during mild to moderate drought, and it was decreased by 33% under late moderate drought stress. Subsequently, an increasing trend was observed. WUE_inst showed an upward trend during the stage from mild to moderate drought. It was increased by 41% at the late moderate drought stage, and then it decreased rapidly. Compared with CK, WUE_inst increased during mild to severe drought, and it reduced after extreme drought. However, when water stress was maintained at the level of moderate or severe drought, the above indicators were similar at the same drought level under continuous drought. Additionally, the values of moderate drought were all higher than those of severe drought (P<0.05). The photosynthesis and transpiration rates were the dominant factors for each other under the mild to moderate stage of continuous drought stress, and stomatal conductance was their common dominant factor under this stress after the late moderate drought and when water stress was maintained at moderate or severe drought. WUE_inst was dominantly influenced by the transpiration rate under well-watered and continuous drought stress, and it was not significantly regulated by leaf gas exchange parameters when water stress was maintained at moderate or severe drought. The research results provide a reference for informing the use of appropriate measures in different drought stages and situations.

Key words: spring wheat, water stress, photosynthetic parameters, stomatal conductance, water use efficiency

陈斐,闫霜,王鹤龄,张凯,赵福年,黄小燕. 不同水分胁迫下的春小麦叶片气体交换参数和水分利用效率研究[J]. 干旱区研究, 2021, 38(3): 821-832.

CHEN Fei,YAN Shuang,WANG Heling,ZHANG Kai,ZHAO Funian,HUANG Xiaoyan. Study on gas exchange parameters and water use efficiency of spring wheat leaves under different levels of water stress[J]. Arid Zone Research, 2021, 38(3): 821-832.

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参考文献 43

[1]	Dang T, Cai G, Guo S, et al. Effect of nitrogen management on yield and water use efficiency of rainfed wheat and maize in Northwest China[J]. Pedosphere, 2006,16(4):495-504. doi: 10.1016/S1002-0160(06)60080-5
[2]	郭天文, 谢永春, 张平良, 等. 不同种植和施肥方式对旱地春玉米土壤水分含量及其水分利用效率的影响[J]. 水土保持学报, 2015,29(5):231-238.
	[ Guo Tianwen, Xie Yongchun, Zhang Pingliang, et al. Effects of different patterns of planting and fertilization on soil moisture and water use efficiency of spring maize on dryland[J]. Jouenal of Soil and Water Conservation, 2015,29(5):231-238. ]
[3]	任丽雯, 王兴涛, 刘明春, 等. 干旱胁迫对土壤水分动态及玉米水分利用效率影响研究[J]. 中国农学通报, 2015,31(32):142-147.
	[ Ren Liwen, Wang Xingtao, Liu Mingchun, et al. Effects of drought stress on soil moisture dynamics and water use efficiency in corn[J]. Chinese Agricultural Science Bulletin, 2015,31(32):142-147. ]
[4]	刘军, 齐广平, 康燕霞, 等. 土壤水分胁迫对紫花苜蓿光合特性及其生物量的影响[J]. 干旱区研究, 2019,36(4):893-900.
	[ Liu Jun, Qi Guangping, Kang Yanxia, et al. Effects of soil water stress on photosynthetic characteristics and biomass of Medicago sativa[J]. Arid Zone Research, 2019,36(4):893-900. ]
[5]	Deng X, Shan L, Zhang H, et al. Improving agricultural water use efficiency in arid and semiarid areas of China[J]. Agricultural Water Management, 2006,80(1-3):23-40. doi: 10.1016/j.agwat.2005.07.021
[6]	魏孝荣, 郝明德, 张春霞, 等. 土壤干旱条件下外源锌、锰对夏玉米光合特性的影响[J]. 作物学报, 2005,31(8):1101-1104.
	[ Wei Xiaorong, Hao Mingde, Zhang Chunxia, et al. Effects of zinc and manganese fertilizers on maize photosynthetic performance under soil drought condition[J]. Acta Agronomica Sinica, 2005,31(8):1101-1104. ]
[7]	Ogutu B, Dash J, Dawson T. Developing a diagnostic model for estimating terrestrial vegetation gross primary productivity using the photosynthetic quantum yield and Earth Observation data[J]. Global Change Biology, 2013,19(9):2878-2892. doi: 10.1111/gcb.2013.19.issue-9
[8]	叶子飘, 张海利, 黄宗安, 等. 叶片光能利用效率和水分利用效率对光响应的模型构建[J]. 植物生理学报, 2017,53(6):1116-1122.
	[ Ye Zipiao, Zhang Haili, Huang Zongan, et al. Model construction of light use efficiency and water use efficiency based on a photosynthetic mechanistic model of light response[J]. Plant Physiology Journal, 2017,53(6):1116-1122. ]
[9]	Maureen T, Alfred O, Hussein S, et al. Leaf gas exchange and water-use efficiency of dry-land wheat genotypes under water stressed and non-stressed conditions[J]. Acta Agriculturae Scandinavica, Section B-Soil & Plant Science, 2018,68(8):738-748.
[10]	贾建英, 赵俊芳, 万信, 等. 黄土高原不同降水区休闲期土壤贮水效率及其对冬小麦水分利用的影响[J]. 生态学报, 2017,37(17):5704-5712.
	[ Jia Jianying, Zhao Junfang, Wan Xin, et al. Effect of soil water storage efficiency on winter wheat water use efficiency in different precipitation areas during the fallow period in the Loess Plateau, western China[J]. Acta Ecologica Sinica, 2017,37(17):5704-5712. ]
[11]	雷俊, 赵福年, 张红兵, 等. 半干旱区不同颜色覆膜对春小麦生长和产量的影响[J]. 干旱气象, 2018,36(4):561-567.
	[ Lei Jun, Zhao Funian, Zhang Hongbing, et al. Effect of different color plastic film mulching on the growth and yield of spring wheat in a semi-arid region[J]. Jouenal of Arid Meterology, 2018,36(4):561-567. ]
[12]	靖华, 亢秀丽, 马爱平, 等. 不同海拔麦田土壤水分变化特征及其对水分利用效率的影响[J]. 干旱气象, 2019,37(4):656-662.
	[ Jing Hua, Kang Xiuli, Ma Aiping, et al. Effect of different altitudes on characteristics of soil water and use efficiency in wheat fields[J]. Jouenal of Arid Meterology, 2019,37(4):656-662. ]
[13]	王建林, 于贵瑞, 房全孝, 等. 不同植物叶片水分利用效率对光和CO2的响应与模拟[J]. 生态学报, 2008,28(2):525-533.
	[ Wang Jianlin, Yu Guirui, Fang Quanxiao, et al. Responses of water use efficiency of nine plant species to light and CO₂ and it’s modeling[J]. Acta Ecologica Sinica, 2008,28(2):525-533. ]
[14]	武兰芳, 欧阳竹. 不同种植密度下两种穗型小麦叶片光合特性的变化[J]. 麦类作物学报, 2008,28(4):618-625.
	[ Wu Lanfang, Ouyang Zhu. Photosynjournal of two spike-type cultivars of winter wheat(Triticum aestivum L.)under different sowing rates[J]. Journal of Triticeae Crops, 2008,28(4):618-625. ]
[15]	路文涛, 贾志宽, 张鹏, 等. 宁南旱区有机培肥对冬小麦光合特性和水分利用效率的影响[J]. 植物营养与肥料学报, 2011,17(5):1066-1074.
	[ Lu Wentao, Jia Zhikuan, Zhang Peng, et al. Effects of organic fertilization on winter wheat photosynthetic characteristics and water use efficiency in semi-arid areas of southern Ningxia[J]. Plant Nutrition and Fertilizer Science, 2011,17(5):1066-1074. ]
[16]	毕润霞, 杨洪强, 杨萍萍, 等. 地下穴灌对苹果冠下土壤水分分布及叶片水分利用效率的影响[J]. 中国农业科学, 2013,46(17):3651-3658.
	[ Bi Runxia, Yang Hongqiang, Yang Pingping, et al. Effect of cavity irrigation underground on the distribution of soil water under the canopy and leaf water use efficiency of apple[J]. Scientia Agricultura Sinica, 2013,46(17):3651-3658. ]
[17]	吴英姿, 胡继超, 张雪松, 等. 环境因子对水稻叶片水分利用效率的影响[J]. 江苏农业科学, 2014,42(5):79-82.
	[ Wu Yingzi, Hu Jichao, Zhang Xuesong, et al. Effects of environmental factors on leaf water use efficiency of rice[J]. Jiangsu Agricultural Sciences, 2014,42(5):79-82. ]
[18]	郑云普, 李菲, 侯毅凯, 等. 大气CO₂浓度增加对作物光合性能及叶片水分利用效率的影响[J]. 农业工程学报, 2019,35(10):91-98.
	[ Zheng Yunpu, Li Fei, Hou Yikai, et al. Effect of increasing CO₂ concentration on photosynjournal and leaf water use efficiency of crops[J]. Transactions of the Chinese Society of Agricultural Engineering, 2019,35(10):91-98. ]
[19]	Shangguan Z, Shao M, Dyckmans J. Nitrogen nutrition and water stress effects on leaf photosynthetic gas exchange and water use efficiency in winter wheat[J]. Environmental and Experimental Botany, 2000,44(2):141-149. pmid: 10996367
[20]	陈晓远, 高志红, 罗远培, 等. 不同土壤水分冬小麦根、冠关系及其对叶片水分利用效率的影响[J]. 中国生态农业学报, 2005,13(2):134-137.
	[ Chen Xiaoyuan, Gao Zhihong, Luo Yuanpei, et al. Relationships between root and shoot of winter wheat under different soil water conditions and their effects on the water use efficiency[J]. Chinese Journal of Eco-Agriculture, 2005,13(2):134-137. ]
[21]	翟丙年, 李生秀. 不同水分状况下施氮对夏玉米水分利用效率的影响[J]. 植物营养与肥料学报, 2005,11(4):473-480.
	[ Zhai Bingnian, Li Shengxiu. Effects of nitrogen nutrition on summer maize water use efficiency under different status of soil moisture[J]. Plant Nutrition and Fertilizer Science, 2005,11(4):473-480. ]
[22]	Dong B, Liu M, Shao H, et al. Investigation on the relation between leaf water use efficiency and physio-biochemical traits of winter wheat under rained condition[J]. Colloids and Surfaces B: Biointerfaces, 2008,62(2):280-287. doi: 10.1016/j.colsurfb.2007.10.023
[23]	于文颖, 纪瑞鹏, 冯锐, 等. 不同生育期玉米叶片光合特性及水分利用效率对水分胁迫的响应[J]. 生态学报, 2015,35(9):2902-2909.
	[ Yu Wenying, Ji Ruipeng, Feng Rui, et al. Response of water stress on photosynthetic characteristics and water use efficiency of maize leaves in different growth stage[J]. Acta Ecologica Sinica, 2015,35(9):2902-2909. ]
[24]	张继波, 薛晓萍, 李楠, 等. 水分胁迫对扬花期冬小麦光合特性和干物质生产及产量的影响[J]. 干旱气象, 2019,37(3):447-453.
	[ Zhang Jibo, Xue Xiaoping, Li Nan, et al. Effects of water stress on photosynthetic characteristics, dry matter production and yield of winter wheat at flowering stage[J]. Jouenal of Arid Meterology, 2019,37(3):447-453. ]
[25]	代立芹, 李春强, 魏瑞江, 等. 河北省冬小麦生长和产量对气候变化的响应[J]. 干旱区研究, 2011,28(2):294-300.
	[ Dai Liqin, Li Chunqiang, Wei Ruijiang, et al. Response of growth and yield of winter wheat to climate change in Hebei province[J]. Arid zone research, 2011,28(2):294-300. ]
[26]	何立谦, 张维宏, 杜雄, 等. 土下覆膜与适宜灌水提高冬小麦水分利用率[J]. 农业工程学报, 2016,32(增1):94-104.
	[ He Liqian, Zhang Weihong, Du Xiong, et al. Soil-coated ultrathin plastic-film mulching and suitable irrigation improve water use efficiency of winter wheat[J]. Transactions of the Chinese Society of Agricultural Engineering, 2016,32(Suppl. 1):94-104. ]
[27]	Yan H, Wu L, Filardo F, et al. Chemical and hydraulic signals regulate stomatal behavior and photosynthetic activity in maize during progressive drought[J]. Acta Physiologiae Plantarum, 2017,39(6):125. doi: 10.1007/s11738-017-2418-5
[28]	Boutraa T, Akhkha A, Al-Shoaibi A, et al. Effect of water stress on growth and water use efficiency(WUE)of some wheat cultivars (Triticum durum)grown in Saudi Arabia[J]. Journal of Taibah University for Science, 2010,3:39-48. doi: 10.1016/S1658-3655(12)60019-3
[29]	贾建英, 韩兰英, 万信, 等. 甘肃省冬小麦干旱灾害风险评估及其区划[J]. 干旱区研究, 2019,36(6):1478-1486.
	[ Jia Jianying, Han Lanying, Wan Xin, et al. Risk and regionalization of drought for winter wheat in Gansu Province[J]. Arid Zone Research, 2019,36(6):1478-1486. ]
[30]	庞桂斌, 徐征和, 杨士红, 等. 控制灌溉水稻叶片水分利用效率影响因素分析[J]. 农业机械学报, 2017,48(4):233-241.
	[ Pang Guibin, Xu Zhenghe, Yang Shihong, et al. Influence factors analysis of rice leaf water use efficiency under controlled irrigation[J]. Transactions of the Chinese Society for Agricultural Machinery, 2017,48(4):233-241. ]
[31]	Pou A, Flexas J, Alsina M, et al. Adjustments of water use efficiency by stomatal regulation during drought and recovery in the drought-adapted Vitis hybrid Richter-110(V. berlandieri×V. rupestris)[J]. Physiologia Plantarum, 2010,134(2):313-323. doi: 10.1111/ppl.2008.134.issue-2
[32]	Hu L, Wang Z, Huang B. Diffusion limitations and metabolic factors associated with inhibition and recovery of photosynjournal from drought stress in a C3 perennial grass species[J]. Physiologia Plantarum, 2010,139(1):93-106. doi: 10.1111/ppl.2010.139.issue-1
[33]	Lawson T, Blatt M. Stomatal size, speed, and responsiveness impact on photosynjournal and water use efficiency[J]. Plant Physiology, 2014,164(4):1556-1570. doi: 10.1104/pp.114.237107 pmid: 24578506
[34]	曹生奎, 冯起, 司建华, 等. 植物叶片水分利用效率研究综述[J]. 生态学报, 2009,29(7):3882-3892.
	[ Cao Shengkui, Feng Qi, Si Jianhua, et al. Summary on the plant water use efficiency at leaf level[J]. Acta Ecologica Sinica, 2009,29(7):3882-3892. ]
[35]	Singh S, Reddy K. Regulation of photosynjournal, fluorescence, stomatal conductance and water-use efficiency of cowpea(Vigna unguiculata L. Walp.)under drought[J]. Journal of Photochemistry and Photobiology B: Biology, 2011,105(1):40-50. doi: 10.1016/j.jphotobiol.2011.07.001
[36]	Blum A. Drought resistance, water-use efficiency, and yield potential-are they compatible, dissonant, or mutually exclusive?[J]. Australian Journal of Agricultural Research, 2005,56(11):1159-1168. doi: 10.1071/AR05069
[37]	Dingkuhn M, Cruz R, O'Toole J, et al. Net photosynjournal, water use efficiency, leaf water potential and leaf rolling as affected by water deficit in tropical upland rice[J]. Australian Journal of Agricultural Research, 1989,40(6):1171-1181. doi: 10.1071/AR9891171
[38]	周怀林, 周广胜. 玉米叶片水分利用效率的保守性[J]. 生态学报, 2019,39(6):2156-2167.
	[ Zhou Huailin, Zhou Guangsheng. Water conservation in terms of leaf water use efficiency of maize(Zea mays L.)[J]. Acta Ecologica Sinica, 2019,39(6):2156-2167. ]
[39]	姚素梅, 刘明久, 茹振钢, 等. ALA对冬小麦叶片气体交换和水分利用效率的影响[J]. 植物营养与肥料学报, 2010,16(1):242-246.
	[ Yao Sumei, Liu Mingjiu, Ru Zhengang, et al. Effects of 5-aminolevulinic acid on leaf gas exchange and water use efficiency in winter wheat[J]. Plant Nutrition and Fertilizer Science, 2010,16(1):242-246. ]
[40]	段爱旺, 肖俊夫, 张寄阳, 等. 控制交替沟灌中灌水控制下限对玉米叶片水分利用效率的影响[J]. 作物学报, 1999,25(6):766-771.
	[ Duan Aiwang, Xiao Junfu, Zhang Jiyang, et al. Effects of irrigation low limits on leaf water use efficiency in maize under controlled alternative furrow irrigation[J]. Acta Agronomica Sinica, 1999,25(6):766-771. ]
[41]	Zhang H, Oweis T, Garabet S, et al. Water-use efﬁciency and transpiration efﬁciency of wheat under rain-fed conditions and supplemental irrigation in a Mediterranean-type environment[J]. Plant and Soil, 1998,201(2):295-305. doi: 10.1023/A:1004328004860
[42]	Masle J, Gilmore S, Farquhar G. The ERECTA gene regulates plant transpiration efficiency in Arabidopsis[J]. Nature, 2005,436:866-870. doi: 10.1038/nature03835
[43]	Deng X, Shan L, Kang S, et al. Improvement of wheat water use efficiency in semiarid area of china[J]. Agricultural Sciences in China, 2003,2(1):35-44.

处理	参数	显著性	LSD
处理	参数	显著性	2015DX	2017DX	2017WW
CK	SW	0.000	a	b	c
	P_n	0.284	a	a	a
	T_r	0.246	a	a	a
	g_s	0.016	a	b	b
	C_i	0.001	a	b	c
	WUE_inst	0.306	a	a	a
WS	SW	0.117	a	ab	b
	P_n	0.885	a	a	a
	T_r	0.812	a	a	a
	g_s	0.611	a	a	a
	C_i	0.922	a	a	a
	WUE_inst	0.808	a	a	a

处理	SW	P_n	T_r	g_s	C_i	WUE_inst
40%FC	6.34±0.97a	17.31±1.92a	4.03±0.72a	0.22±0.08a	221.60±28.55a	4.50±0.33a
30%FC	3.94±1.15b	8.42±2.55b	2.19±0.86b	0.08±0.09b	182.53±23.75b	3.80±0.49b

处理	参数	因子	相关系数	直接通径系数	间接通径系数
处理	参数	因子	相关系数	直接通径系数	P_n/(μmol·m^-2·s^-1)	g_s/(mol·m^-2·s^-1)	C_i/(μmol·mol^-1)	T_r/(mmol·m^-2·s^-1)	合计
CK	P_n	g_s	0.445^*	1.511	-	-	-1.034	-0.031	-1.065
		C_i	0.073	-1.220	-	1.281	-	0.012	1.293
		T_r	0.088	-0.208	-	0.225	0.071	-	0.296
	T_r	P_n	0.088	-0.377	-	0.543	-0.078	-	0.465
		g_s	0.149	1.22	-0.168	-	-0.903	-	-1.071
		C_i	-0.058	-1.065	-0.028	1.034	-	-	1.006
	WUE_inst	P_n	0.347	0.478	-	-0.069	0.015	-0.077	-0.131
		g_s	0.102	-0.155	0.213	-	0.175	-0.131	0.257
		C_i	0.161	0.207	0.035	-0.131	-	0.051	-0.045
		T_r	-0.872^**	-0.879	0.042	-0.023	-0.012	-	0.007

处理	参数	因子	相关系数	直接通径系数	间接通径系数
处理	参数	因子	相关系数	直接通径系数	P_n/(μmol·m^-2·s^-1)	g_s/(mol·m^-2·s^-1)	C_i/(μmol·mol^-1)	T_r/(mmol·m^-2·s^-1)	合计
WS	P_n	g_s	0.919^**	0.07	-	-	-0.006	0.855	0.849
		C_i	-0.268	-0.166	-	0.003	-	-0.105	-0.102
		T_r	0.981^**	0.895	-	0.067	0.019	-	0.086
	T_r	P_n	0.981^**	0.88	-	0.131	-0.03	-	0.101
		g_s	0.956^**	0.143	0.809	-	0.004	-	0.813
		C_i	-0.117	0.113	-0.236	0.005	-	-	-0.231
	WUE_inst	P_n	0.516^**	0.662	-	0.54	0.23	-0.916	-0.146
		g_s	0.271	0.587	0.609	-	-0.033	-0.892	-0.316
		C_i	-0.903^**	-0.857	-0.177	0.022	-	0.109	-0.046
		T_r	0.378^*	-0.933	0.65	0.561	0.1	-	1.311
WSF	P_n	g_s	0.936^**	0.0133	-	-	0.089	0.834	0.923
		C_i	0.936^**	0.0942	-	0.013	-	0.829	0.842
		T_r	0.99^**	0.8898	-	0.012	0.088	-	0.100
	T_r	P_n	0.99^**	0.9137	-	0.081	-0.004	-	0.077
		g_s	0.937^**	0.0862	0.855	-	-0.004	-	0.851
		C_i	0.932^**	-0.0047	0.855	0.081	-	-	0.936
	WUE_inst	P_n	-0.877^**	1.2495	-	1.094	-1.034	-2.187	-2.127
		g_s	-0.775^**	1.1691	1.17	-	-1.044	-2.07	-1.944
		C_i	-0.889^**	-1.1044	1.17	1.105	-	-2.059	0.216
		T_r	-0.906^**	-2.2092	1.237	1.095	-1.029	-	1.303
WSL	P_n	g_s	0.956^**	0.6272	-	-	0.147	0.182	0.329
		C_i	-0.73^*	-0.2675	-	-0.344	-	-0.118	-0.462
		T_r	0.973^**	0.1849	-	0.617	0.171	-	0.788
	T_r	P_n	0.973^**	0.1273	-	0.77	0.076	-	0.846
		g_s	0.984^**	0.8052	0.122	-	0.057	-	0.179
		C_i	-0.639^*	-0.104	-0.093	-0.442	-	-	-0.535
	WUE_inst	P_n	0.831^**	-0.2119	-	-0.24	0.501	0.782	1.043
		g_s	0.714^*	-0.2513	-0.203	-	0.376	0.791	0.964
		C_i	-0.907^**	-0.6857	0.155	0.138	-	-0.514	-0.221
		T_r	0.789^**	0.8042	-0.206	-0.247	0.438	-	-0.015

处理	参数	因子	相关系数	直接通径系数	间接通径系数
处理	参数	因子	相关系数	直接通径系数	P_n /(μmol·m^-2·s^-1)	g_s /(mol·m^-2·s^-1)	C_i /(μmol·mol^-1)	T_r /(mmol·m^-2·s^-1)	合计
40%FC	P_n	g_s	0.986^**	1.1517	-	-	-0.18	0.014	-0.166
		C_i	0.806^*	-0.2067	-	1.003	-	0.01	1.013
		T_r	0.825^*	0.018	-	0.917	-0.11	-	0.807
	T_r	P_n	0.825^*	0.285	-	1.032	-0.492	-	0.540
		g_s	0.796^*	1.0464	0.281	-	-0.531	-	-0.250
		C_i	0.531	-0.6102	0.23	0.911	-	-	1.141
	WUE_inst	P_n	-0.248	1.7255	-	-3.29	1.573	-0.256	-1.973
		g_s	-0.183	-3.3372	1.701	-	1.7	-0.247	3.154
		C_i	0.271	1.9519	1.391	-2.907	-	-0.165	-1.681
		T_r	-0.507	-0.3105	1.424	-2.656	1.036	-	-0.196
30% FC	P_n	g_s	0.982^**	1.1631	-	-	-0.214	0.033	-0.181
		C_i	0.608	-0.2865	-	0.87	-	0.024	0.894
		T_r	0.95^**	0.0345	-	1.119	-0.203	-	0.916
	T_r	P_n	0.95^**	-3.8146	-	5.444	-0.679	-	4.765
		g_s	0.962^**	5.5438	-3.746	-	-0.836	-	-4.582
		C_i	0.71	-1.1175	-2.319	4.147	-	-	1.828
	WUE_inst	P_n	-0.263	-0.3759	-	3.472	-0.436	-2.923	0.113
		g_s	-0.33	3.5362	-0.369	-	-0.537	-2.96	-3.866
		C_i	-0.486	-0.7178	-0.229	2.645	-	-2.185	0.231
		T_r	-0.542	-3.0771	-0.357	3.402	-0.51	-	2.535