不同温度条件下高原多年生牧草幼苗的生理和生长对碱胁迫的响应

Responses of Physiology and Growth of Plateau Perennial Grass Seedlings to Alkali Stress Under Different Temperature Conditions

【目的】选取对碱性土壤耐受性较强的牧草改良土壤。【方法】该试验在低温(6~15℃)和室温(20~25℃)2种温度条件下(2种温度相对照),以不同浓度0(CK)、50、100、200、300 mmol·L^-1的Na2CO3溶液处理青牧一号老芒麦、青海草地早熟禾、同德老芒麦、洽草4种牧草的幼苗,观察其生理指标的变化。【结果】(1)4种牧草可溶性糖含量在2种温度处理间都有差异,且低温(6~15℃)处理下不同碱胁迫浓度之间含量差异显著;(2)青海草地早熟禾在2种温度处理下,SOD酶活都随着碱胁迫浓度的升高而出现先增加后降低的趋势,且都在100 mmol·L^-1时达到峰值;(3)在相同浓度处理下,室温(20~25℃)条件处理下的青牧一号老芒麦MDA含量显著高于低温(6~15℃)条件处理下的MDA含量;(4)在碱胁迫浓度较高(100、200、300 mmol·L^-1)时,洽草的MDA含量在室温与低温处理间差异显著,且低温处理显著高于室温处理;(5)同德老芒麦除50 mmol·L^-1外,在低温(6~15℃)处理时的SOD酶活与室温(20~25℃)处理下的SOD酶活存在显著性,且低温处理显著高于室温处理;(6)4种牧草茎长在2种温度处理下,都随着碱浓度的升高而降低。【结论】综上所述,青海草地早熟禾在低温环境下对碱胁迫的抗逆性较强。

【Objective】The present paper aimed to choose grasses that were more tolerant to alkaline soils to improve the soil.【Method】The test was carried out at different temperatures 0(CK), 50, 100, 200, 300 mmol·L^-1 of Na2CO3 solution at low temperature of 6-15 ℃ and room temperature of 20-25 ℃(two temperatures as CK). The seedlings of four kinds of forages, such as Laomengmai, Qinghai meadow bluegrass, Tongde Laomangmai and Qiongcao, were observed for changes of their physiological indexes. 【Result】(i) The soluble sugar content of the four herbages was different between the two treatments, and the difference in the concentration of different alkali stresses was significant at low temperature(6-15 ℃).(ii) Under the two temperature treatments, the activity of SOD in Qinghai grassland increased first and then decreased with the increase of alkali stress concentration and peaked at 100 mmol·L^-1.(iii)In the same concentration treatment, the MDA content of Qingmu No.1 Mangmai under the condition of indoor temperature(20-25 ℃) was significantly higher than that under the low temperature(6-15 ℃).(iv)When the alkali stress concentration was higher(100, 200, 300 mmol·L^-1), the MDA content of the grass was significantly different between indoor temperature and low temperature treatment, and the low temperature treatment was significantly higher than the indoor temperature treatment.(v)In addition to 50 mmol·L^-1, the SOD activity were significant at the low temperature(6-15 ℃) and at indoor temperature(20-25 ℃), and the low temperature treatment was significant higher than the indoor temperature treatment.(vi)The stem lengths of the four herbage species decreased with the increase of alkali concentration under the two temperature treatments. 【Conclusion】In summary, the bluegrass had a strong resistance to alkali stress in low temperature environment.