壳寡糖浸种对低温下花生种子萌发及生理代谢的影响

为提高播种期花生抗寒性，明确壳寡糖（COS）浸种对低温条件下花生种子发芽及生理代谢的影响，测定COS浸种后种子发芽及相关生理指标。结果表明，与低温对照（CK）相比，COS（250 mg/L）浸种显著提高了低温下花生种子的发芽能力，发芽率和相对发芽率均增加了44.45个百分点、发芽指数和种子活力指数分别增加了5.59和24.83；COS浸种也显著提高了发芽过程中花生种子的赤霉素（GA）含量，降低了脱落酸（ABA）含量，发芽0、12、24、36、48 h的GA含量分别显著提高了7.94%、3.84%、8.52%、12.40%、19.20%，ABA含量分别显著降低了38.41%、36.99%、38.03%、41.20%、40.12%；同时，COS浸种提高了脂肪酶（LIP）、蛋白酶（PR）、α-淀粉酶（α-AMS）和超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）的活性，增加了三磷酸腺苷（ATP）和可溶性糖（SS）、可溶性蛋白（SP）、脯氨酸（Pro）的含量，降低了丙二醛（MDA）和过氧化氢（H₂O₂）的含量。研究表明，COS通过调节低温下花生种子发芽初期的激素水平、提高水解酶活性，促进贮藏物质分解，并提高抗氧化物酶活性、增加渗透调节物质含量，减缓脂膜过氧化，促进种子萌发。

Effects of chitooligosaccharide soaking on germination and physiological metabolism of peanut seeds

To investigate the effects of chitooligosaccharide （COS） soaking on germination and physiological metabolism of peanut seeds under low temperature, seed germination and related physiological indexes of peanut were observed following immersion in chitooligosaccharide solution. Results showed that 250 mg/L COS significantly increased peanut germination at low temperature. Compared with no soaking control, both germination rate and relative germination rate increased by 44.45 percentage points, germination index and seed vigor index increased by 5.59 and 24.83, respectively. COS soaking also significantly increased gibberellin content and decreased abscisic acid content of peanut seeds during germination. The content of gibberellin in germinating seeds at 0, 12, 24, 36 and 48 h were significantly increased by 7.94%, 3.84%, 8.52%, 12.40% and 19.20%, and abscisic acid content was significantly decreased by 38.41%, 36.99%, 38.03%, 41.20%, 40.12%. Meanwhile, COS soaking increased the activities of lipase, protease, α-amylase, superoxide dismutase, peroxidase and catalase, and accumulated the quantities of adenosine triphosphate, soluble sugar, soluble protein and proline, while decreased the contents of malondialdehyde and hydrogen peroxide. Studies revealed that COS could regulate hormone level of peanut seeds and improve the activities of hydrolase at the early germination stage under low temperature environment, promote the decomposition of storage substances, and also enhance the activity of antioxidant enzymes, increase the content of osmotic regulatory substances, slow down lipid membrane peroxidation, which promote seed germination.