高级检索

    寒旱逆境下不同类型转基因小黑杨生长差异与评价

    Growth differences and evaluation of different types of transgenic Populus simonii × P. nigra under cold and drought stress

      摘要
    • 摘要:
      目的 评价转TaLEA、betA及PsnWRKY70基因小黑杨无性系在寒旱逆境下的生长适应性及生理响应机制，筛选兼具速生与高抗逆性的小黑杨优良转基因株系，以期为我国寒旱地区杨树抗逆育种提供优良候选材料。
      方法 在黑龙江省错海林场（寒温带半干旱气候）营建转基因小黑杨环境释放试验林，对5年生TaLEA过表达、betA过表达、PsnWRKY70过表达及抑制表达4类转基因小黑杨与野生型对照进行田间观测。测定树高、胸径、材积和保存率等生长指标，并于典型干旱期采样分析丙二醛（MDA）含量、超氧化物歧化酶（SOD）活性、过氧化氢（H2O2）含量及气孔密度等生理指标。采用方差分析、多重比较和隶属函数法对不同转基因类型株系进行综合评价与筛选。
      结果 参试无性系在树高、胸径、材积和保存率等方面均存在显著差异（P < 0.05）。以综合评价值 ≥ 0.70为筛选阈值，共选出4个优良无性系，包括3个PsnWRKY70抑制表达（b23、b17、b15）和1个TaLEA过表达（XL-7）小黑杨无性系。其中，b23无性系表现最优，树高达6.14 m，保存率为72.5%，其在干旱条件下MDA含量低、SOD活性高、H2O2积累少、叶片气孔密度小，表现出较强的氧化胁迫抗性和水分保持能力；XL-7无性系在生长与抗逆性方面也显著优于对照。
      结论 PsnWRKY70抑制表达可显著增强小黑杨在寒旱地区的田间生长与存活能力，其主要作用机制与抗氧化能力的提升和细胞膜稳定性增强密切相关。本研究筛选出的b23、b17、b15和XL-7等转基因小黑杨优良无性系，兼具速生性与高抗逆性，为寒旱地区杨树抗逆育种提供了具有应用潜力的新种质。

       

      Abstract:
      Objective This study aimed to evaluate the growth adaptability and physiological response mechanisms of transgenic Populus simonii × P. nigra clones (with TaLEA, betA, and PsnWRKY70 genes) under cold and drought stress, to screen genotypes combining fast growth with high stress resistance, thereby providing candidate materials for poplar breeding in cold and arid regions of China.
      Method An environmental release trial was established at Cuohai Forest Farm in Heilongjiang Province (cold-temperate, semi-arid climate). Field observations were conducted on 5-year-old transgenic lines and wild-type (WT) controls. Growth traits including tree height, diameter at breast height (DBH), stem volume, and survival rate were measured. During the typical drought period, physiological indicators including malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, hydrogen peroxide (H2O2) content, and stomatal density were analyzed. Analysis of variance (ANOVA), multiple comparisons, and the membership function method were used for comprehensive evaluation and selection.
      Result There were significant differences (P < 0.05) in tree height, DBH, volume, and survival rate among the tested clones. With a comprehensive evaluation value ≥ 0.70 as the screening threshold, 4 excellent clones were selected, including 3 PsnWRKY70 suppression expression clones (b23, b17, b15) and 1 TaLEA overexpression clone (XL-7). Among them, clone b23 performed the best, with a tree height of 6.14 m and a survival rate of 72.5%. Under drought conditions, clone b23 exhibited low MDA content, high SOD activity, low H2O2 accumulation, and low leaf stomatal density, showing strong resistance to oxidative stress and water retention capacity. Clone XL-7 also showed significantly better growth and stress resistance than the control.
      Conclusion Suppressing PsnWRKY70 expression significantly enhance the field growth and survival ability of Populus simonii × Populus nigra in cold and arid conditions, primarily by boosting antioxidant capacity and cell membrane stability. The selected transgenic clones (b23, b17, b15, and XL-7), combining fast growth with high stress resistance, provide promising new germplasm for stress-resistant poplar breeding in cold, arid regions.

       

      • HTML全文
      • 参考文献(28)
      • 相关文章
      • 施引文献
    • 资源附件(0)

    /

    返回文章
    返回