寒冷区苏打盐碱生境下紫花苜蓿越冬期根颈的生理特性

doi:10.11686/cyxb2024386

摘要/Abstract

摘要：

根颈是紫花苜蓿根系与茎部的过渡结构，对苜蓿返青具有重要影响。为了明确在寒冷区苏打盐碱生境下，紫花苜蓿自然越冬过程中根颈的生理特性，选取了在大庆地区越冬率存在差异性的龙牧801（越冬率96.59%）和骑士T（越冬率83.54%）两个苜蓿品种，定期监测两个苜蓿品种在大田自然越冬状态下苜蓿根颈超氧化物岐化酶（SOD）、过氧化物酶（POD）活性和游离脯氨酸（Pro）、可溶性蛋白（SP）、可溶性总糖（SS）、丙二醛（MDA）含量及根颈组织含水量（TWC），综合分析在苏打盐碱和冬季低温复合胁迫下的苜蓿根颈生理特性变化。结果表明：在苏打盐碱与冬季低温的复合胁迫下，随低温胁迫时间延长苜蓿根颈内TWC逐渐降低，SS、SP、Pro含量逐渐升高，均在次年2月达到峰值，龙牧801根颈SS含量更高，骑士T根颈Pro含量更高；苜蓿根颈内SOD、POD活性和MDA含量呈双峰趋势变化，龙牧801与骑士T相比根颈SOD活性更强，MDA积累量更少，寒潮下POD活性更高。综上所述，在冬季盐碱和低温复合胁迫下龙牧801能在根颈内积累更多的可溶性糖，维持根颈水分稳定，并在强低温胁迫影响时维持更强的抗氧化酶系统活性，以降低细胞膜过氧化程度，从而获得更高的越冬率。

关键词: 越冬期, 苏打盐碱, 苜蓿, 根颈, 生理特性

Abstract:

The root collar or crown of alfalfa （Medicago sativa） is a transitional structure connecting roots and stems， and has an important role in alfalfa greening. This research aimed to clarify the physiological characteristics of the alfalfa root collar during overwintering under soda saline-alkali stress in a cold area. Two alfalfa varieties Longmu No.801 （over-winter survival rate 96.59%） and Stockpile （over-winter survival rate 83.54%）， were tested in Daqing. The activities of superoxide dismutase （SOD） and peroxidase （POD）， and the contents of free proline （Pro）， soluble protein （SP）， total soluble sugar （SS）， malondialdehyde （MDA） and tissue water content （TWC） in root collar of two alfalfa varieties were monitored at six time points during overwintering （late September， October， November， December， February and April） in the field. The physiological characteristics of the alfalfa root collar in test plants under combined stresses of soda saline-alkali and low temperature in winter were analyzed using a multivariate procedure. It was found that under the combined stresses of soda saline-alkali and low temperature in winter， alfalfa root collar TWC gradually decreased with increase in the low temperature stress exposure time， and the contents of SS， SP and Pro gradually increased， reaching a peak in February of the following year. The SS content of Longmu No.801 was higher than Stockpile， while the Pro content of Stockpile was higher than Longmu No.801. SOD and POD activities together with MDA content in alfalfa root collars showed a bimodal winter pattern， with peaks in late November and February， and the February peak in the variety Stockpile significantly higher than Longmu No.801 for all three parameters. Compared with Stockpile， Longmu No.801 had stronger SOD activity and less MDA accumulation， and POD activity was higher under cold exposure. In summary， under the combined stress of soda saline and winter cold， Longmu No.801 accumulated more SS in the root collar， maintained a more stable TWC in the root collar， and maintained stronger activities of antioxidant enzymes， than the variety Stockpile， which had lower over-winter survival. These root collar physiological characteristics are therefore indicated by our research to be linked to the variety differences in overwinter survival in saline-alkali conditions.

Key words: during overwintering stage, soda saline-alkali, alfalfa, root collar, physiological characteristics

陈宁, 包凤轩, 赵辉祥, 王楠, 姜汝玉, 李国良, 刘香萍, 曲善民, 杨伟光. 寒冷区苏打盐碱生境下紫花苜蓿越冬期根颈的生理特性[J]. 草业学报, 2025, 34(9): 78-86.

Ning CHEN, Feng-xuan BAO, Hui-xiang ZHAO, Nan WANG, Ru-yu JIANG, Guo-liang LI, Xiang-ping LIU, Shan-min QU, Wei-guang YANG. Physiological characteristics of the alfalfa root collar during overwintering under soda saline-alkali stress in cold areas[J]. Acta Prataculturae Sinica, 2025, 34(9): 78-86.

图/表 10

表1 供试苜蓿材料及来源

Table 1 Source and materials of tested alfalfa

品种

Variety

来源

Source

抗寒级

Cold resistance

秋眠级

Fall dormancy

越冬率

Wintering rate （%）

龙牧801 Longmu No.801

M. ruthenica Sojak×M. sativa ‘Longmu No.801’

黑龙江省农业科学院Heilongjiang Academy of Agricultural Sciences

1.0

96.59±1.04a

骑士T Stockpile M. sativa ‘Stockpile’

北京佰青源畜牧业科技发展有限公司Beijing Baiqingyuan Animal Husbandry Technology Development Co.， Ltd.

1.4

3.9

83.54±0.99b

表2 样地土壤类型及理化性质

Table 2 Soil types and physical and chemical properties of sample area

土壤类型

Soil type

电导率

Conductivity

（mS·cm^-1）

CO₃^2-含量

CO₃^2- content （g·kg^-1）

HCO₃^-含量HCO₃^-content （g·kg^-1）

Cl^-含量

Cl^- content （g·kg^-1）

SO₄^2-含量

SO₄^2- content （g·kg^-1）

Na^＋含量

Na^＋ content （g·kg^-1）

碱解氮含量

Available nitrogen （mg·kg^-1）

有效磷含量

Available phosphorus （mg·kg^-1）

苏打盐碱土Soda saline-alkali soil

表 3 采样时期及气温

Table 3 Sampling period and temperature

编号 Code	采样日期 Sampling date	最高温度 Maximum temperature （℃）	最低温度 Minimum temperature （℃）
T₁	2023-09-26	22	14
T₂	2023-10-28	13	2
T₃	2023-11-28	-12	-18
T₄	2023-12-30	-13	-17
T₅	2024-02-28	-6	-15
T₆	2024-04-24	18	10

图1 越冬期内不同苜蓿品种根颈组织含水量不同小写字母表示同一品种不同时期差异显著（P<0.05）。*表示品种间差异显著（P<0.05），**表示品种间差异极显著（P<0.01）。横坐标中T1~T6表示不同取样时期，编号详见表3。下同。Different lowercase letters indicate significant difference among sampling date in the same variety （P<0.05）. * indicates significant difference between two varieties （P<0.05）. ** indicates extremely significant level （P<0.01）. T1-T6 in the abscissa represents the code of sampling date. For the code， refer to Table 3. The same below.

Fig.1 The tissue water content in root collar of different alfalfa varieties during overwintering stage

图2 越冬期内不同苜蓿品种根颈可溶性蛋白含量FW：该指标以鲜重为基准This parameter is referenced to fresh weight. 下同The same below.

Fig.2 The soluble protein content in root collar of different alfalfa varieties during overwintering stage

图3 越冬期内不同苜蓿品种根颈可溶性总糖含量DW：该指标以干重为基准This parameter is referenced to dry weight.

Fig.3 The soluble sugar content in root collar of different alfalfa varieties during overwintering stage

图4 越冬期内不同苜蓿品种根颈内游离脯氨酸含量

Fig.4 The content of free proline in root collar of different alfalfa varieties during overwintering stage

图5 越冬期内不同苜蓿品种根颈丙二醛含量

Fig.5 The malondialdehyde content in root collar of different alfalfa varieties during overwintering stage

图6 越冬期内不同苜蓿品种根颈超氧化物歧化酶活性

Fig.6 The superoxide dismutase activity in root collar of different alfalfa varieties during overwintering stage

图7 越冬期内不同苜蓿品种根颈过氧化物酶活性

Fig.7 The peroxidase activity in root collar of different alfalfa varieties during overwintering stage