1College of Horticulture，Hunan Agricultural University，Changsha 410128，Hunan，China；2Engineering Research Centre of the Ministry of Education for Germplasm Innovation and New Variety Selection of Horticultural Crops，Changsha 410128，Hunan，China；3Hunan Provincial Key Laboratory of Vegetable Biology，Changsha 410128，Hunan，China
Abstract：In order to study the effects of exogenous growth regulators on morphological and physiological indexes of seedlings under low-temperature and low-light stress，seven exogenous growth regulators were used to treat chilli seedlings with ‘Xingshu 301’，including 0.1 μmol · L-1 oleandrin lactones（BRs），100 μmol · L-1 melatonin（MT），500 μmol · L-1 salicylic acid（SA），100 μmol · L-1 abscisic acid（ABA），300 mg · L-1 6-benzyl adenine（6-BA），100 μmol · L-1 methyl jasmonate（MeJA），and 20 μmol · L-1 monocrotaline（GR24）. The results showed that，compared with the ambient control，the stoutness index of chilli seedlings under low-temperature low-light stress was significantly reduced，and the contents of soluble sugars，proline and malondialdehyde in the leaves were significantly increased；the chlorophyll
content and catalase activity were significantly decreased. Compared with the low-temperature and low-light control，the seedling index and leaf soluble sugars，proline，chlorophyll content and catalase activity were significantly increased，malondialdehyde content was decreased，chlorophyll fluorescence parameter Fv/Fm and photochemical burst coefficient（qP）were increased，and non-photochemical burst coefficient（NPQ）was decreased by the treatments of the exogenous growth regulators. However，the effects of different exogenous growth regulators to alleviate low-temperature and low-light stress varied，and ABA，MT，and GR24 were more effective. The effect of exogenous growth regulators was obvious in the early stage of low-temperature and low-light stress（5 days），and the difference was not significant after 5 days of growth resumption. It has
shown that low temperature and low light stress would affect the growth of chilli seedlings，and exogenous growth regulator treatments were effective in alleviating the damage of adversity stress on chilli seedlings in the early stage；there were differences in the effects of different exogenous growth regulator treatments，and ABA，MT，and GR24 significantly enhanced the ability of chilli seedlings to tolerate low temperature and low light，of which 100 μmol · L-1 ABA had the best effect.
朱程红，付稳，张正，兰嘉仪，李诗，袁思怡，戴雄泽. 外源生长调节物质对低温弱光胁迫下辣椒幼苗生长的影响[J]. 中国蔬菜, 2024, 1(3): 40-50.
ZHU Chenghong，FU Wen，ZHANG Zheng，LAN Jiayi，LI Shi，YUAN Siyi，DAI Xiongze. Effect of Exogenous Growth Regulating Substances on the Growth of Chilli Seedlings under Low Temperature and Low Light Stress. China Vegetables, 2024, 1(3): 40-50.
