褪黑素引发处理提高朝天椒种子萌发及幼苗耐盐性的生理机制  

Physiological mechanism of melatonin soaking on improving seed germination and seedling salt tolerance of pepper

作　　者：魏茜雅 林欣琪 梁腊梅 秦中维 李映志[1] WEI Xi-ya;LIN Xin-qi;LIANG La-mei;QIN Zhong-wei;LI Ying-zhi(College of Coastal Agricultural Sciences,Guangdong Ocean University,Zhanjiang 524088,China)

机构地区：[1]广东海洋大学滨海农学院,广东湛江524088

出　　处：《江苏农业学报》2022年第6期1637-1647,共11页Jiangsu Journal of Agricultural Sciences

基　　金：广东海洋大学创新强校项目(GDOU2013050217、GDOU2016050256)。

摘　　要：为促进盐胁迫下朝天椒种子萌发和幼苗生长,以未引发处理为对照,设置不同浓度(0μmol/L、1μmol/L、5μmol/L、25μmol/L、50μmol/L、75μmol/L、100μmol/L、125μmol/L、150μmol/L、200μmol/L)的褪黑素引发处理,分析褪黑素引发处理对朝天椒种子在盐胁迫下(100 mmol/L NaCl)的萌发和幼苗生长状况以及生理指标的影响。结果表明:100μmol/L褪黑素引发处理能最大程度缓解盐胁迫对朝天椒种子萌发的影响,并促进幼苗生长。与未引发处理种子相比,100μmol/L褪黑素引发处理后,种子发芽率、发芽势、发芽指数和活力指数分别增加了33.84%、120.27%、108.13%和312.71%;植株鲜质量、根鲜质量、地上部鲜质量和植株干质量分别增加了48.61%、102.57%、52.99%和180.00%。100μmol/L褪黑素引发处理后,与未引发处理相比,种子丙二醛和过氧化氢含量分别降低了74.26%、67.16%;可溶性糖、可溶性蛋白和脯氨酸含量分别增加了51.88%、157.54%和28.72%;POD和CAT活性分别提高了185.57%和53.23%;APX活性及AsA、DHA含量和AsA/DHA值分别提高了27.57%、1 377.00%、41.19%和880.37%;盐胁迫下,经100μmol/L褪黑素引发处理后生长的朝天椒幼苗过氧化氢和超氧阴离子含量分别比未引发处理对照降低了58.65%和42.00%;可溶性糖、可溶性蛋白和脯氨酸含量分别增加了38.89%、384.61%和37.46%;SOD和POD活性分别提高了240.24%和398.59%;APX活性及AsA、DHA含量和AsA/DHA值分别提高了106.89%、618.35%、134.26%和206.78%,差异显著。这些结果表明,使用100μmol/L的褪黑素对朝天椒种子进行引发处理,能够抑制氧化物质的生成,提高抗氧化酶活性,进而促进种子在盐胁迫下的萌发和幼苗生长。本研究结果可为朝天椒耐盐栽培和育种提供参考。In order to promote the seed germination and seedling growth of pepper under salt stress, different concentrations(0 μmol/L, 1 μmol/L, 5 μmol/L, 25 μmol/L, 50 μmol/L, 75 μmol/L, 100 μmol/L, 125 μmol/L, 150 μmol/L, 200 μmol/L) of melatonin soaking were set up with non-soaking as control(CK). The effects of melatonin soaking on seed germination and seedling growth of pepper under salt stress(100 mmol/L NaCl) and physiological indices were analyzed. The results showed that 100 μmol/L melatonin soaking could alleviate the effects of salt stress on seed germination and promote seedling growth. Compared with non-soaked seeds, the germination rate, germination potential, germination index and vigor index of seeds soaked with 100 μmol/L melatonin increased by 33.84%, 120.27%, 108.13% and 312.71%, respectively. Seedling fresh weight, root fresh weight, shoot fresh weight and plant dry weight increased by 48.61%, 102.57%, 52.99% and 180.00%, respectively. After soaking with 100 μmol/L melatonin, the contents of malondialdehyde and hydrogen peroxide in seeds decreased by 74.26% and 67.16%, respectively, compared with those without soaking. The contents of soluble sugar, soluble protein and proline increased by 51.88%, 157.54% and 28.72%, respectively. The activities of peroxidase(POD) and catalase(CAT) increased by 185.57% and 53.23%, respectively. Ascorbate peroxidase(APX) activity, ascorbic acid(AsA) content, dehydroascorbic acid(DHA) content, AsA/DHA value increased by 27.57%, 1 377.00%, 41.19% and 880.37%, respectively. Under salt stress, the contents of hydrogen peroxide and superoxide anion in seedlings treated with 100 μmol/L melatonin decreased by 58.65% and 42.00%, respectively, compared with the CK. The contents of soluble sugar, soluble protein and proline increased by 38.89%, 384.61% and 37.46%, respectively. The activities of superoxide dismutase(SOD) and POD increased by 240.24% and 398.59%, respectively. The APX activity, AsA content, DHA content and AsA/DHA value increased by 106.89%, 618.35%,

关 键 词：褪黑素 盐胁迫 朝天椒 种子萌发 幼苗生长 

分 类 号：S641.3[农业科学—蔬菜学]