河南农业科学 ›› 2023, Vol. 52 ›› Issue (8): 69-77.DOI: 10.15933/j.cnki.1004-3268.2023.08.008

• 作物栽培·遗传育种 • 上一篇    下一篇

干旱胁迫对桔梗光合作用和生理特性的影响

信龙飞,娄闯,冀保毅,刘红云,张艳玲   

  1. (信阳农林学院,河南 信阳 464000)
  • 收稿日期:2022-12-07 出版日期:2023-08-15 发布日期:2023-08-29
  • 通讯作者: 张艳玲(1973-),女,河南信阳人,副教授,硕士,主要从事中药材栽培与中药资源开发利用研究。E-mail:xynzzl@126.com
  • 作者简介:信龙飞(1989-),男,河南郸城人,讲师,博士,主要从事药用植物生理生态研究。E-mail:cnxinlongfei@126.com
  • 基金资助:
    河南省科技攻关项目(222102110338,212102110285,212102110287);信阳农林学院青年基金项目(2019LG013);信阳农林学院青年骨干教师培养计划项目(2021)

Effects of Drought Stress on Photosynthesis and Physiological Characteristics of Platycodon grandiflorum

XIN Longfei,LOU Chuang,JI Baoyi,LIU Hongyun,ZHANG Yanling   

  1. (Xinyang Agriculture and Forestry University,Xinyang 464000,China)
  • Received:2022-12-07 Published:2023-08-15 Online:2023-08-29

摘要: 为了探究干旱胁迫对桔梗光合作用和生理特性的影响,以2年生桔梗为试验材料,设置4个土壤水分处理,分别为土壤相对含水量的80%(对照)、60%(轻度干旱)、40%(中度干旱)、20%(重度干旱),研究不同程度干旱胁迫下桔梗的光合和生理特性。结果表明,随着干旱程度的增加,桔梗叶片净光合速率、气孔导度、胞间CO2浓度、光饱和点、表观量子效率和暗呼吸速率均呈逐渐下降趋势,而光补偿点逐渐升高。当土壤相对含水量为20%时,光补偿点最高,为74.45 μmol/(m2·s),比对照上升了67.76%。叶片光合色素含量先升高后下降,土壤相对含水量60%处理下叶绿素a、叶绿素b和类胡萝卜素含量最高,分别较对照增加了18.71%、28.48%、12.25%。桔梗丙二醛、脯氨酸、可溶性糖、可溶性蛋白含量均随干旱程度的增加而增加。过氧化氢酶活性先升后降,土壤相对含水量为40%时活性最强,较对照提高了21.01%。综上,桔梗对轻度和中度干旱表现出一定的适应性,渗透调节物质积累和抗氧化酶活性增加是桔梗耐旱性的关键生理响应过程,但重度干旱胁迫下桔梗膜脂过氧化程度加剧,光合生产力显著下降,最终导致桔梗生长受到严重抑制。桔梗种植管理时,土壤相对含水量不宜长时间低于40%。

关键词: 桔梗, 干旱胁迫, 抗氧化酶, 渗透调节物质, 光合特性

Abstract: Two‑year‑old Platycodon grandiflorum was used to explore the effects of drought stress on its photosynthesis and physiological characteristics.The response of P.grandiflorum to different degree of drought stress was analyzed by measuring the photosynthetic and physiological characteristics under different soil moisture conditions.The soil relative water content was 80%(control),60%(mild drought),40%(moderate drought)and 20%(severe drought),respectively.The findings suggested that the net photosynthetic rate,stomatal conductance,intercellular CO2 concentration,light saturation point,apparent quantum yield and dark respiration rate of P.grandiflorum leaves decreased gradually with the increasing degree of drought stress.The light compensation point increased gradually.When the soil relative water content was 20%,the highest light compensation point achieved 74.45 μmol/(m2·s),which increased by 67.76% compared with the control.However,the content of photosynthetic pigments in leaves increased first and then decreased with the increasing degree of drought stress.The contents of chlorophyll a,chlorophyll b and carotenoids were the highest under soil relative water content of 60%,which increased by 18.71%,28.48%,and 12.25% respectively compared with the control.Moreover,the contents of malondialdehyde,proline,soluble sugar and soluble protein in P.grandiflorum increased with the increasing degree of drought stress.The catalase activity in P.grandiflorum leaves enhanced first and then weakened.The activity was the highest when the soil relative water content was 40%,which was 21.01% higher than that of the control.In summary,P.grandiflorum showed adaptability to mild and moderate drought.The accumulation of osmotic adjustment substances and the increase of antioxidant enzyme activity were the key physiological response processes of drought tolerance of P.grandiflorum.However,the lipid peroxidation of P.grandiflorum was aggravated under severe drought stress,and the photosynthetic productivity decreased significantly,which eventually led to serious inhibition of the growth of P.grandiflorum.To maintain the normal growth of P.grandiflorum,soil relative water content should not be lower than 40% for a long time.

Key words: Platycodon grandiflorum, Drought stress, Antioxidant enzyme, Osmotic adjustment substance, Photosynthetic characteristics

中图分类号: