Effect of Drought Stress on Root Morphology and Leaf Photosynthetic Characteristics of Good Taste japonica Rice from Late Stage of Panicle Differentiation to Early Stage of Grain Filling

doi:10.16819/j.1001-7216.2024.230804

Abstract

Abstract:

【Objective】 The study aims to investigate the impact of soil drought from the late stage of panicle differentiation to the early stage of grain filling, on root morphology, physiology, and leaf photosynthetic characteristics of high-quality japonica rice. This research provides a theoretical foundation for drought-resistant cultivation. 【Method】 Nanjing 9108 and Fengjing 1606 were chosen as test materials. Two soil drought treatments were implemented: light drought (LD, soil water potential at −20±5 kPa) and severe drought (SD, soil water potential at −40±5 kPa). These treatments were applied for 20 days, spanning from the late stage of panicle differentiation to the early stage of grain filling (BAH, 10 days before & 10 days after heading), 10 days during the late stage of panicle differentiation (BH, 10 days before heading), and 10 days during the early stage of grain filling (AH, 10 days after heading). A well-watered treatment was used as the control (CK). 【Result】 1) Root length, root surface area, root volume, root tip number, root dry weight, and root activity for treatments within BAH, BH, AH followed a trend of SD<LD<CK at the end of drought stresses, 10 days after the end of drought stresses, 30 days after heading, and maturity. However, the root-shoot ratio exhibited the opposite trend. At the end of drought stresses, root indicators for SD and LD treatments within BAH significantly differed from CK, while root indicators for SD within BH and AH significantly differed from CK, except for the root-shoot ratio. Root indicators for LD treatments within BH and AH were not significantly different from CK. At the three stages after the end of drought stresses, root indicators for SD within BAH significantly differed from CK, and LD treatments were not significantly different except for root tip number. Root surface area, root volume, root tip number, and root dry weight for SD treatments within BH significantly differed from CK, while no significant differences were observed among the three water treatments within AH. 2) Net photosynthetic rate (P_n), transpiration rate (T_r), stomatal conductance (G_s), intercellular CO₂ concentration (C_i), maximum photochemical efficiency (F_v/F_m), and photochemical quenching coefficient (q_p) for the treatments within BAH, BH, AH showed SD<LD<CK at the end of drought stresses, 10 days after the end of drought stresses, 30 days after heading, and maturity. Conversely, non-photochemical quenching coefficient (NPQ) exhibited the opposite trend. At the end of drought stresses, indicators of photosynthetic parameters for SD and LD treatments within BAH significantly differed from CK, and there were significant differences between LD and SD, except for C_i. Indicators for SD treatments within BH and AH significantly differed from CK, while LD treatments were not significantly different from CK. At the three stages after the end of drought stresses, indicators for SD treatments within BAH significantly differed from CK, while LD treatments did not. Only P_n, T_r, and F_v/F_m for SD treatments within BH significantly differed from CK, with no significant differences observed among the three water treatments within AH. 3) Yield for drought treatments within all three periods showed SD<LD<CK. Significant differences were observed among the three drought treatments within BAH and BH, with no significant difference between LD and CK within AH, both of which significantly differed from SD. 【Conclusion】 SD and LD within BAH inhibited root growth and leaf photosynthesis, resulting in a significant reduction in yield, with a smaller impact under LD. Plants under SD within BH found it challenging to return to control levels after treatment, leading to yield reduction. In contrast, plants under SD and LD within AH could recover quickly after treatment. In conclusion, rice root and leaf growth are more sensitive to drought treatments during the BH period in the late stage of panicle differentiation and early stage of grain filling.

Key words: late stage of panicle differentiation and early stage of grain filling, high-quality japonica rice, drought stress, root morphology and physiology, photosynthetic characteristics, chlorophyll fluorescence

摘要：

【目的】研究穗分化末期至灌浆初期土壤干旱对优质食味粳稻根系形态生理与叶片光合特性的影响，为水稻抗旱栽培提供理论参考。【方法】以南粳9108和丰粳1606为供试材料，分别在穗分化末期至籽粒灌浆初期20 d(BAH)、穗分化末期10 d(BH)与灌浆初期10 d(AH)设置轻度干旱(LD, ψ_soil = −20±5 kPa)、重度干旱(SD, ψ_soil = −40±5 kPa)及常规水分(CK)处理。【结果】1）在处理结束当天、处理结束后10 d、穗后30 d与成熟期，根长、根表面积、根体积、根尖数、根干质量与根系活力均表现为SD<LD<CK，根冠比呈相反趋势。在处理结束时，BAH时段SD、LD均与CK差异显著，除根冠比外，BH、AH时段SD与CK差异显著，LD与CK无显著差异。处理结束后10 d、穗后30 d与成熟期，BAH时期SD与CK差异显著，除根尖数外LD与CK差异不显著，BH时期SD根系部分指标与CK差异显著，AH时期水分处理间无显著差异。2）在处理结束时、处理结束后10 d、穗后30 d与成熟期，剑叶净光合速率(P_n)、蒸腾速率(T_r)、气孔导度(G_s)、胞间CO₂浓度(C_i)、最大光化学效率(F_v/F_m)、光化学猝灭系数(q_p)均表现为SD<LD<CK，非光化学猝灭系数(NPQ)呈相反趋势。在处理结束时，BAH时段SD、LD各指标均与CK差异显著，除C_i外SD、LD间差异也显著，BH、AH时段SD各指标均与CK差异显著，LD与CK差异不显著。在处理结束后10 d、穗后30 d与成熟期，BAH时段SD与CK差异显著，LD与CK差异多不显著，BH时段SD的P_n、T_r、F_v/F_m较CK差异显著，而AH时段各指标在水分处理间差异多数不显著。3）三处理时段下各胁迫处理间产量均表现为SD<LD<CK，BAH、BH时段不同水分处理间差异显著，AH时段LD、CK间无显著差异，但二者均与SD差异显著。【结论】BAH时期轻度干旱、重度干旱均会抑制根系生长与叶片光合能力，显著降低产量，其中轻度干旱影响较小。BH时期土壤重度干旱时，根、叶形态生理指标在处理结束后难以恢复至对照水平，AH时期轻度干旱、重度干旱处理各指标在处理结束后能较快恢复。可见，在穗分化末期至灌浆初期，水稻根系和叶片生长对穗分化末期干旱胁迫更为敏感。

关键词: 穗分化末期至灌浆初期, 优质食味粳稻, 干旱胁迫, 根系形态生理, 光合特性, 叶绿素荧光

JING Xiu, ZHOU Miao, WANG Jing, WANG Yan, WANG Wang, WANG Kai, GUO Baowei, HU Yajie, XING Zhipeng, XU Ke, ZHANG Hongcheng. Effect of Drought Stress on Root Morphology and Leaf Photosynthetic Characteristics of Good Taste japonica Rice from Late Stage of Panicle Differentiation to Early Stage of Grain Filling[J]. Chinese Journal OF Rice Science, 2024, 38(1): 33-47.

景秀, 周苗, 王晶, 王岩, 王旺, 王开, 郭保卫, 胡雅杰, 邢志鹏, 许轲, 张洪程. 穗分化末期－灌浆初期干旱胁迫对优质食味粳稻根系形态和叶片光合特性的影响[J]. 中国水稻科学, 2024, 38(1): 33-47.

Figures/Tables 11

References 40

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处理时段	干旱处理	土壤水势
Processing period	Drought treatment	Soil water potential/kPa
抽穗前1－10 d与抽穗后1~10 d 10 d before heading and 10 d after heading, BAH	轻度干旱 Light drought, LD	−20±5
	重度干旱 Severe drought, SD	−40±5
	常规水分处理 CK	0
抽穗前1－10 d 1~10 d before heading, BH	轻度干旱 Light drought, LD	−20±5
	重度干旱 Severe drought, SD	−40±5
	常规水分处理 CK	0
抽穗后1－10 d 1~10 d after heading, AH	轻度干旱 Light drought, LD	−20±5
	重度干旱 Severe drought, SD	−40±5
	常规水分处理 CK	0

处理时段	干旱处理	土壤水势
Processing period	Drought treatment	Soil water potential/kPa
抽穗前1－10 d与抽穗后1~10 d 10 d before heading and 10 d after heading, BAH	轻度干旱 Light drought, LD	−20±5
	重度干旱 Severe drought, SD	−40±5
	常规水分处理 CK	0
抽穗前1－10 d 1~10 d before heading, BH	轻度干旱 Light drought, LD	−20±5
	重度干旱 Severe drought, SD	−40±5
	常规水分处理 CK	0
抽穗后1－10 d 1~10 d after heading, AH	轻度干旱 Light drought, LD	−20±5
	重度干旱 Severe drought, SD	−40±5
	常规水分处理 CK	0

品种 Variety	处理时段 Processing period	土壤水分处理 Soil water treatment	胁迫结束时At the end of drought stress				胁迫结束后10 d 10 d after drought stress
品种 Variety	处理时段 Processing period	土壤水分处理 Soil water treatment	总根长 Root length / (×10³cm·hill^-1)	根表面积 Root surface area/ (×10³cm²·hill^-1)	根体积 Root volume/ (cm³·hill^-1)	根尖数 Root tip number/ (×10⁴·hill^-1)	总根长 Root length / (×10³cm·hill^-1)	根表面积 Root surface area/ (×10³cm²·hill^-1)	根体积 Root volume/ (cm³·hill^-1)	根尖数 Root tip number/ (×10⁴·hill^-1)
南粳 9108 Nanjing 9108	BAH	CK	79.52±2.94 a	10.44±0.77 a	97.14±4.15 a	49.09±1.98 a	72.71±0.67 a	10.44±0.77 a	85.88±2.18 a	43.58±2.11 a
		LD	72.70±1.80 b	9.17±0.58 b	85.76±1.82 b	40.59±1.42 b	70.61±0.71 a	9.17±0.58 b	83.43±2.01 a	37.06±2.16 b
		SD	66.11±2.83 c	8.06±0.75 c	82.09±3.13 b	34.87±1.30 c	63.59±1.97 b	8.06±0.75 c	75.31±4.49 b	34.48±2.96 b
	BH	CK	82.52±1.23 a	11.23±1.04 a	101.31±3.18 a	53.98±2.50 a	79.52±2.94 a	11.23±1.04 a	97.14±1.23 a	49.09±1.98 a
		LD	81.61±1.30 a	10.81±1.14 a	99.70±1.21 a	50.33±3.50 ab	78.71±0.53 a	10.81±1.14 a	96.63±1.61 a	46.28±2.52 ab
		SD	78.94±1.08 b	9.79±0.49 b	93.52±3.47 b	46.92±3.36 b	78.08±2.03 a	9.79±0.49 b	92.79±0.86 b	42.17±3.03 b
	AH	CK	79.52±1.97 a	10.44±0.77 a	97.14±4.15 a	49.09±1.98 a	72.71±0.67 a	10.44±0.77 a	85.88±2.18 a	43.58±2.11 a
		LD	78.53±1.06 a	10.23±0.75 a	96.32±1.62 a	48.41±1.04 ab	73.04±1.05 a	10.23±0.75 a	85.31±1.46 a	42.67±1.91 a
		SD	76.30±0.35 b	9.27±0.92 b	95.15±1.51 b	47.18±1.11 b	71.92±1.55 a	9.27±0.92 b	84.72±1.15 a	41.25±1.50 a
丰粳 1606 Fengjing1606	BAH	CK	70.84±1.84 a	8.04±0.82 a	89.11±3.02 a	36.20±1.90 a	65.62±0.97 a	8.04±0.82 a	80.25±3.87 a	33.84±1.33 a
		LD	64.17±1.03 b	6.75±0.30 b	80.68±0.86 b	27.56±1.39 b	63.78±0.85 a	6.75±0.30 b	77.87±2.72 ab	27.11±2.32 b
		SD	57.83±1.50 c	6.34±0.90 b	75.20±1.84 c	25.29±2.45 b	57.69±2.73 b	6.34±0.90 b	73.32±4.79 b	25.07±1.04 b
	BH	CK	71.24±0.31 a	8.41±1.04 a	93.50±2.24 a	38.46±1.91 a	70.84±1.84 a	8.41±1.04 a	89.11±3.02 a	36.20±1.90 a
		LD	71.13±0.66 a	8.23±0.71 a	91.54±2.15 a	36.59±0.66 ab	69.43±1.73 a	8.23±0.71 a	87.95±3.11 a	33.21±1.03 ab
		SD	69.03±1.29 b	7.29±0.63 b	84.50±0.68 b	33.68±1.07 b	67.87±0.36 a	7.29±0.63 b	84.10±2.17 b	30.88±2.12 b
	AH	CK	70.84±1.84 a	8.04±0.82 a	89.11±3.02 a	36.20±1.90 a	65.62±0.97 a	8.04±0.82 a	80.25±3.87 a	33.84±1.33 a
		LD	70.69±1.07 a	7.73±0.20 ab	87.60±2.08 ab	36.12±0.67 a	66.04±1.39 a	7.73±0.20 ab	80.06±3.30 a	32.90±1.69 a
		SD	68.17±0.65 b	7.42±0.60 b	84.90±1.39 b	33.72±1.21 b	65.39±1.11 a	7.42±0.60 b	79.81±1.54 a	32.65±0.64 a
品种 Variety	处理时段 Processing period	土壤水分处理 Soil water treatment	穗后30 d 30 d after heading				成熟期 Maturity
品种 Variety	处理时段 Processing period	土壤水分处理 Soil water treatment	总根长 Root length / (×10³cm·hill^-1)	根表面积 Root surface area/ (×10³cm²·hill^-1)	根体积 Root volume/ (cm³·hill^-1)	根尖数 Root tip number/ (×10⁴·hill^-1)	总根长 Root length / (×10³cm·hill^-1)	根表面积 Root surface area/ (×10³cm²·hill^-1)	根体积 Root volume/ (cm³·hill^-1)	根尖数 Root tip number/ (×10⁴·hill^-1)
南粳 9108 NJ9108	BAH	CK	58.23±2.59 a	8.44±0.87 a	72.84±1.97 a	32.35±3.73 a	36.71±1.67 a	5.33±0.74 a	63.64±1.05 a	23.81±1.56 a
		LD	56.48±1.50 a	7.87±0.54 ab	68.76±2.68 ab	26.96±1.22 b	35.08±0.65 ab	5.04±0.22 ab	61.52±1.83 ab	21.07±1.77 b
		SD	51.09±1.73 b	7.09±0.71 b	63.65±2.53 b	25.86±1.06 b	33.95±0.52 b	4.72±0.69 b	57.58±3.51 b	20.09±1.19 b
	BH	CK	58.23±2.59 a	8.44±0.87 a	72.84±1.97 a	32.35±3.73 a	36.71±1.67 a	5.33±0.74 a	63.64±1.05 a	23.81±1.56 a
		LD	57.81±0.82 a	8.38±0.56 a	71.99±2.85 a	29.63±0.61 ab	35.61±2.31 a	5.21±0.66 a	62.30±1.07 ab	22.42±0.92 ab
		SD	57.38±1.15 a	7.65±0.71 b	65.97±1.92 b	25.86±1.13 b	35.15±1.57 a	4.92±0.51 b	59.45±2.17 b	20.78±1.05 b
	AH	CK	58.23±2.59 a	8.44±0.87 a	72.84±1.97 a	32.35±3.73 a	36.71±1.67 a	5.33±0.74 a	63.64±1.05 a	23.81±1.56 a
		LD	59.62±1.15 a	8.26±0.42 a	71.64±0.78 a	31.52±0.99 a	36.26±3.19 a	5.26±0.61 a	62.84±1.66 a	23.22±0.86 a
		SD	57.42±1.36 a	8.16±0.89 a	71.08±3.75 a	31.13±1.91 a	35.84±1.29 a	5.20±0.35 a	62.54±1.11 a	23.04±1.09 a
丰粳 1606 FJ1606	BAH	CK	54.98±1.63 a	6.64 ±1.04 a	64.11±3.65 a	27.90±1.82 a	32.13±1.74 a	4.54±0.55 a	47.50±1.22 a	17.90±2.52 a
		LD	52.50±2.79 a	6.28±0.56 ab	62.29±1.62 ab	23.61±2.09 b	31.33±0.91 ab	4.34±0.69 ab	45.99±2.68 ab	15.93±0.81 b
		SD	47.69±2.12 b	5.68±0.50 b	59.62±3.20 b	22.70±0.90 b	29.36±0.77 b	4.18±0.71 b	41.84±3.18 b	14.93±1.90 b
	BH	CK	54.98±1.63 a	6.64±1.04 a	64.11±3.65 a	27.90±1.82 a	32.13±1.74 a	4.54±0.55 a	47.50±1.22 a	17.90±2.52 a
		LD	54.06±0.58 a	6.48±0.54 ab	62.54±1.62 a	25.68±1.05 ab	31.24±2.89 a	4.43±0.57 ab	47.01±1.43 a	17.28±0.98 ab
		SD	53.78±0.90 a	6.04±0.71 b	56.66±1.66 b	22.39±0.57 b	30.97±0.99 a	4.31±0.70 b	44.08±1.04 b	16.02±1.09 b
	AH	CK	54.98±1.63 a	6.64±1.04 a	64.11±3.65 a	27.90±1.82 a	32.13±1.74 a	4.54±0.55 a	47.50±1.22 a	17.90±2.52 a
		LD	54.82±1.00 a	6.53±1.09 a	63.94±1.64 a	27.63±1.03 a	33.10±0.98 a	4.49±0.24 a	47.05±1.15 a	17.50±1.22 a
		SD	54.51±0.93 a	6.47±1.08 a	63.73±2.29 a	27.33±0.95 a	32.02±1.03 a	4.44±0.84 a	47.17±1.84 a	17.38±0.91 a

品种 Variety	处理时段 Processing period	土壤水分处理 Soil water treatment	胁迫结束时At the end of drought stress				胁迫结束后10 d 10 d after drought stress
品种 Variety	处理时段 Processing period	土壤水分处理 Soil water treatment	总根长 Root length / (×10³cm·hill^-1)	根表面积 Root surface area/ (×10³cm²·hill^-1)	根体积 Root volume/ (cm³·hill^-1)	根尖数 Root tip number/ (×10⁴·hill^-1)	总根长 Root length / (×10³cm·hill^-1)	根表面积 Root surface area/ (×10³cm²·hill^-1)	根体积 Root volume/ (cm³·hill^-1)	根尖数 Root tip number/ (×10⁴·hill^-1)
南粳 9108 Nanjing 9108	BAH	CK	79.52±2.94 a	10.44±0.77 a	97.14±4.15 a	49.09±1.98 a	72.71±0.67 a	10.44±0.77 a	85.88±2.18 a	43.58±2.11 a
		LD	72.70±1.80 b	9.17±0.58 b	85.76±1.82 b	40.59±1.42 b	70.61±0.71 a	9.17±0.58 b	83.43±2.01 a	37.06±2.16 b
		SD	66.11±2.83 c	8.06±0.75 c	82.09±3.13 b	34.87±1.30 c	63.59±1.97 b	8.06±0.75 c	75.31±4.49 b	34.48±2.96 b
	BH	CK	82.52±1.23 a	11.23±1.04 a	101.31±3.18 a	53.98±2.50 a	79.52±2.94 a	11.23±1.04 a	97.14±1.23 a	49.09±1.98 a
		LD	81.61±1.30 a	10.81±1.14 a	99.70±1.21 a	50.33±3.50 ab	78.71±0.53 a	10.81±1.14 a	96.63±1.61 a	46.28±2.52 ab
		SD	78.94±1.08 b	9.79±0.49 b	93.52±3.47 b	46.92±3.36 b	78.08±2.03 a	9.79±0.49 b	92.79±0.86 b	42.17±3.03 b
	AH	CK	79.52±1.97 a	10.44±0.77 a	97.14±4.15 a	49.09±1.98 a	72.71±0.67 a	10.44±0.77 a	85.88±2.18 a	43.58±2.11 a
		LD	78.53±1.06 a	10.23±0.75 a	96.32±1.62 a	48.41±1.04 ab	73.04±1.05 a	10.23±0.75 a	85.31±1.46 a	42.67±1.91 a
		SD	76.30±0.35 b	9.27±0.92 b	95.15±1.51 b	47.18±1.11 b	71.92±1.55 a	9.27±0.92 b	84.72±1.15 a	41.25±1.50 a
丰粳 1606 Fengjing1606	BAH	CK	70.84±1.84 a	8.04±0.82 a	89.11±3.02 a	36.20±1.90 a	65.62±0.97 a	8.04±0.82 a	80.25±3.87 a	33.84±1.33 a
		LD	64.17±1.03 b	6.75±0.30 b	80.68±0.86 b	27.56±1.39 b	63.78±0.85 a	6.75±0.30 b	77.87±2.72 ab	27.11±2.32 b
		SD	57.83±1.50 c	6.34±0.90 b	75.20±1.84 c	25.29±2.45 b	57.69±2.73 b	6.34±0.90 b	73.32±4.79 b	25.07±1.04 b
	BH	CK	71.24±0.31 a	8.41±1.04 a	93.50±2.24 a	38.46±1.91 a	70.84±1.84 a	8.41±1.04 a	89.11±3.02 a	36.20±1.90 a
		LD	71.13±0.66 a	8.23±0.71 a	91.54±2.15 a	36.59±0.66 ab	69.43±1.73 a	8.23±0.71 a	87.95±3.11 a	33.21±1.03 ab
		SD	69.03±1.29 b	7.29±0.63 b	84.50±0.68 b	33.68±1.07 b	67.87±0.36 a	7.29±0.63 b	84.10±2.17 b	30.88±2.12 b
	AH	CK	70.84±1.84 a	8.04±0.82 a	89.11±3.02 a	36.20±1.90 a	65.62±0.97 a	8.04±0.82 a	80.25±3.87 a	33.84±1.33 a
		LD	70.69±1.07 a	7.73±0.20 ab	87.60±2.08 ab	36.12±0.67 a	66.04±1.39 a	7.73±0.20 ab	80.06±3.30 a	32.90±1.69 a
		SD	68.17±0.65 b	7.42±0.60 b	84.90±1.39 b	33.72±1.21 b	65.39±1.11 a	7.42±0.60 b	79.81±1.54 a	32.65±0.64 a
品种 Variety	处理时段 Processing period	土壤水分处理 Soil water treatment	穗后30 d 30 d after heading				成熟期 Maturity
品种 Variety	处理时段 Processing period	土壤水分处理 Soil water treatment	总根长 Root length / (×10³cm·hill^-1)	根表面积 Root surface area/ (×10³cm²·hill^-1)	根体积 Root volume/ (cm³·hill^-1)	根尖数 Root tip number/ (×10⁴·hill^-1)	总根长 Root length / (×10³cm·hill^-1)	根表面积 Root surface area/ (×10³cm²·hill^-1)	根体积 Root volume/ (cm³·hill^-1)	根尖数 Root tip number/ (×10⁴·hill^-1)
南粳 9108 NJ9108	BAH	CK	58.23±2.59 a	8.44±0.87 a	72.84±1.97 a	32.35±3.73 a	36.71±1.67 a	5.33±0.74 a	63.64±1.05 a	23.81±1.56 a
		LD	56.48±1.50 a	7.87±0.54 ab	68.76±2.68 ab	26.96±1.22 b	35.08±0.65 ab	5.04±0.22 ab	61.52±1.83 ab	21.07±1.77 b
		SD	51.09±1.73 b	7.09±0.71 b	63.65±2.53 b	25.86±1.06 b	33.95±0.52 b	4.72±0.69 b	57.58±3.51 b	20.09±1.19 b
	BH	CK	58.23±2.59 a	8.44±0.87 a	72.84±1.97 a	32.35±3.73 a	36.71±1.67 a	5.33±0.74 a	63.64±1.05 a	23.81±1.56 a
		LD	57.81±0.82 a	8.38±0.56 a	71.99±2.85 a	29.63±0.61 ab	35.61±2.31 a	5.21±0.66 a	62.30±1.07 ab	22.42±0.92 ab
		SD	57.38±1.15 a	7.65±0.71 b	65.97±1.92 b	25.86±1.13 b	35.15±1.57 a	4.92±0.51 b	59.45±2.17 b	20.78±1.05 b
	AH	CK	58.23±2.59 a	8.44±0.87 a	72.84±1.97 a	32.35±3.73 a	36.71±1.67 a	5.33±0.74 a	63.64±1.05 a	23.81±1.56 a
		LD	59.62±1.15 a	8.26±0.42 a	71.64±0.78 a	31.52±0.99 a	36.26±3.19 a	5.26±0.61 a	62.84±1.66 a	23.22±0.86 a
		SD	57.42±1.36 a	8.16±0.89 a	71.08±3.75 a	31.13±1.91 a	35.84±1.29 a	5.20±0.35 a	62.54±1.11 a	23.04±1.09 a
丰粳 1606 FJ1606	BAH	CK	54.98±1.63 a	6.64 ±1.04 a	64.11±3.65 a	27.90±1.82 a	32.13±1.74 a	4.54±0.55 a	47.50±1.22 a	17.90±2.52 a
		LD	52.50±2.79 a	6.28±0.56 ab	62.29±1.62 ab	23.61±2.09 b	31.33±0.91 ab	4.34±0.69 ab	45.99±2.68 ab	15.93±0.81 b
		SD	47.69±2.12 b	5.68±0.50 b	59.62±3.20 b	22.70±0.90 b	29.36±0.77 b	4.18±0.71 b	41.84±3.18 b	14.93±1.90 b
	BH	CK	54.98±1.63 a	6.64±1.04 a	64.11±3.65 a	27.90±1.82 a	32.13±1.74 a	4.54±0.55 a	47.50±1.22 a	17.90±2.52 a
		LD	54.06±0.58 a	6.48±0.54 ab	62.54±1.62 a	25.68±1.05 ab	31.24±2.89 a	4.43±0.57 ab	47.01±1.43 a	17.28±0.98 ab
		SD	53.78±0.90 a	6.04±0.71 b	56.66±1.66 b	22.39±0.57 b	30.97±0.99 a	4.31±0.70 b	44.08±1.04 b	16.02±1.09 b
	AH	CK	54.98±1.63 a	6.64±1.04 a	64.11±3.65 a	27.90±1.82 a	32.13±1.74 a	4.54±0.55 a	47.50±1.22 a	17.90±2.52 a
		LD	54.82±1.00 a	6.53±1.09 a	63.94±1.64 a	27.63±1.03 a	33.10±0.98 a	4.49±0.24 a	47.05±1.15 a	17.50±1.22 a
		SD	54.51±0.93 a	6.47±1.08 a	63.73±2.29 a	27.33±0.95 a	32.02±1.03 a	4.44±0.84 a	47.17±1.84 a	17.38±0.91 a

变异来源 Source of variation	总根长 Root length	根表面积 Root surface area	根体积 Root volume	根尖数 Root tip number	根干质量 Root dry weight	根冠比 Root-shoot rate	根系活力 Root activity	净光合速率 Net photosynthetic rate	产量 Yield
品种Variety(V)	46.19**	117.89**	107.88**	67.94**	42.26**	63.32**	56.91**	154.41**	17.86**
处理时段 Treatment period(P)	4.00*	11.20**	8.44**	10.17**	14.22**	4.06*	5.46**	10.43**	35.75**
土壤水分 Soil water content(SW)	8.39**	17.82**	19.54**	25.51**	34.50**	21.38**	20.81**	17.45**	108.78**
V×P	0.04	0.45	1.80	0.10	2.40	15.11**	0.10	0.12	0.16
V×SW	0.44	0.29	0.50	0.21	2.18	0.40	0.68	0.07	0.74
P×SW	2.31	5.39*	3.08*	3.48*	3.97**	4.10**	3.09*	3.43*	9.03**
V×P×SW	1.02	0.12	0.47	0.09	0.73	0.06	0.11	0.19	0.16