EFFECTS OF ROOT PRUNING AT THE REGREENING STAGE ON DROUGHT TOLERANCE AND WATER USE EFFICIENCY OF WINTER WHEAT IN LATE GROWING STAGE

doi:10.3773/j.issn.1005-264x.2008.05.024

Abstract

Abstract:

Aims Water use efficiency (WUE) and drought tolerance of crops are important in arid and semiarid areas. Our objective was to investigate the effects of root pruning at the regreening stage on drought tolerance and WUE of winter wheat (Triticum aestivum) in late growing stage.

Methods We manipulated root size by root pruning regreening plants grown in pots. In a light root pruning treatment, we partially cut off the secondary lateral roots along one side of the plant. In a heavy root pruning treatment, we partially cut off the secondary lateral roots along four sides of the plant. Control plants (CK) were left intact.

Important findings Both the root pruning treatments reduced the root system significantly, but their root/shoot ratio remained similar. The values of chlorophyll fluorescence parameters, i.e., the maximum photochemical efficiency of PSⅡ (F_v/F_m), PSⅡ potential activity (F_v/F_o), effective PSⅡ quantum yield (Φ_PSⅡ), apparent rate of photosynthetic electron transport (ETR), coefficient of photochemical quenching (q_P) and coefficient of non-photochemical quenching (NPQ), were significantly higher in both treatments than the control 8 days after withholding water at anthesis. This means that root pruning improved drought tolerance of wheat, resulting in improved photosynthetic capability. Light root pruning had no significant effects on grain yield under wet condition, but improved yield under moderate drought stress. Therefore, light root pruning wheat produced a higher index of drought resistance compared with the control. Light root pruning improved WUEof wheat under two water conditions. Heavy root pruning did not improve WUE or the index of drought resistance due to a reduced shoot density and grain yield. The study showed that reducing root size moderately through breeding or agricultural measures would be beneficial to improving drought tolerance and WUEin winter wheat.

Key words: winter wheat, root pruning, drought tolerance, water use efficiency

MA Shou-Chen, LI Feng-Min, XU Bing-Cheng, HUANG Zhan-Bin. EFFECTS OF ROOT PRUNING AT THE REGREENING STAGE ON DROUGHT TOLERANCE AND WATER USE EFFICIENCY OF WINTER WHEAT IN LATE GROWING STAGE[J]. Chin J Plant Ecol, 2008, 32(5): 1194-1200.

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URL: https://www.plant-ecology.com/EN/10.3773/j.issn.1005-264x.2008.05.024

https://www.plant-ecology.com/EN/Y2008/V32/I5/1194

Figures/Tables 4

References 16

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处理 Treatments		地下部分生物量 RDW (g·pot^-1)	地上部分生物量 SDW (g·pot^-1)	根冠比 Root/shoot ratio
高水处理 High-watered soil (85% FWC)	CK	8.65±0.6^a	71.97±2.3^a	0.12^a
	A	7.65±0.4^b	65.72±3.2^b	0.11^a
	B	6.37±0.3^c	59.16±2.8^c	0.11^a
中度干旱处理 Moderate drought stress (55% FWC)	CK	7.91±0.5^a	49.18±2.1^a	0.16^a
	A	7.32±0.6^b	52.96±2.5^a	0.15^a
	B	6.83±0.3^c	42.03±1.7^b	0.15^a

处理 Treatments		地下部分生物量 RDW (g·pot^-1)	地上部分生物量 SDW (g·pot^-1)	根冠比 Root/shoot ratio
高水处理 High-watered soil (85% FWC)	CK	8.65±0.6^a	71.97±2.3^a	0.12^a
	A	7.65±0.4^b	65.72±3.2^b	0.11^a
	B	6.37±0.3^c	59.16±2.8^c	0.11^a
中度干旱处理 Moderate drought stress (55% FWC)	CK	7.91±0.5^a	49.18±2.1^a	0.16^a
	A	7.32±0.6^b	52.96±2.5^a	0.15^a
	B	6.83±0.3^c	42.03±1.7^b	0.15^a

处理 Treatments	中度干旱Moderate drought stress (55% FWC)						抗旱系数 DI
处理 Treatments	穗数 Spike number	穗粒重Spike grain weight (g)	产量 Yield (g·pot^-1)	穗数 Spike number	穗粒重Spike grain weight (g)	产量 Yield (g·pot^-1)	抗旱系数 DI
CK	16±1.2^a	1.43±0.02^b	22.3±0.8^b	26±1.2^a	1.17±0.1^bc	30.01±1.2^a	0.74±0.04^b
A	17±1.6^a	1.47±0.02^a	25.18±1.6^a	23±0.6^b	1.32±0.08^a	29.94±1.0^a	0.84±0.06^a
B	13±0.9^b	1.41±0.04^b	18.34±1.2^c	20±1.4^c	1.25±0.11^ab	25.79±1.4^b	0.71±0.07^b

处理 Treatments	中度干旱Moderate drought stress (55% FWC)						抗旱系数 DI
处理 Treatments	穗数 Spike number	穗粒重Spike grain weight (g)	产量 Yield (g·pot^-1)	穗数 Spike number	穗粒重Spike grain weight (g)	产量 Yield (g·pot^-1)	抗旱系数 DI
CK	16±1.2^a	1.43±0.02^b	22.3±0.8^b	26±1.2^a	1.17±0.1^bc	30.01±1.2^a	0.74±0.04^b
A	17±1.6^a	1.47±0.02^a	25.18±1.6^a	23±0.6^b	1.32±0.08^a	29.94±1.0^a	0.84±0.06^a
B	13±0.9^b	1.41±0.04^b	18.34±1.2^c	20±1.4^c	1.25±0.11^ab	25.79±1.4^b	0.71±0.07^b

处理 Treatments	高水处理 High-watered soil (85% FWC)		中度干旱 Moderate drought stress (55% FWC)
处理 Treatments	耗水量 Water consumption (kg)	水分利用效率 WUE (g·kg^-1)	耗水量 Water consumption (kg)	水分利用效率 WUE (g·kg^-1)
CK	21.15±0.6^a	1.46±0.09^b	14.88±0.45^a	1.55±0.03^b
A	19.04±0.4^b	1.57±0.2^a	13.52±0.3^b	1.85±0.1^a
B	17.82±0.6^c	1.45±0.1^b	12.58±0.4^c	1.51±0.2^b