油茶种子性状及浸种后内源激素含量分析

An analysis of seed traits and endogenous hormone levels after seed soakings in Camellia oleifera

【目的】研究油茶种子性状,分析油茶种子浸种期间吸水率及吸水速率,探讨种子浸水机制下内源激素动态变化规律,为标准化砧木培育提供技术支撑。【方法】以‘长林3号’(3号)、‘长林4号’(4号)、‘长林40号’(40号)、‘长林18号’(18号)、‘长林53号’(53号)种子为试验材料,测定种子形状参数、体积,并在人工气候控制条件下计算不同浸种时间的吸水率和吸水速率;利用液质联用(LC-MS)方法对‘长林18号’(18号)种子浸种不同时间和温度条件下赤霉素(GA3)、脱落酸(ABA)、水杨酸(SA)和茉莉酸(JA)、生长素(IAA)和玉米素核苷(ZR)含量进行检验,采用单因素方差分析比较不同条件下各激素含量差异。【结果】品种间种子体积由大到小依次为长林53号、40号、18号、3号、4号,且53号与其他品种存在显著差异;种子三维系数显示长林3号、4号和40号多呈扁平状,18号和53号多近球形,且种子三维系数与种子横径长度显著相关;3号和4号种子体积与纵径存在显著或极显著正相关,40号和53号横径与侧径存在显著负相关,18号种子体积与形状参数无相关性。各品种浸种48 h后吸水率和吸水速率逐渐稳定;种子浸种0~21 h,53号吸水率最高,40号最低;浸种21~48 h吸水率由大到小依次为4号、3号、53号、40号和18号。各品种吸水速率在浸种10 h内,由大到小依次为40号、4号、3号、53号、18号,浸种10 h后53号最高。种子浸种后的发芽率无显著差异,由大到小依次为4号、40号、53号、3号和18号。18号浸种后GA3含量逐渐上升,在浸种2 d时达到最高,为039 mg/kg;SA和JA含量在浸种4 d时达到最高,分别为0058 mg/kg和177 mg/kg;ABA含量在浸种2 d和5 d时达到最高,约为0050 mg/kg,4 d时最低为0014 mg/kg。m(GA3)/m(ABA)在浸种1 d和4 d时维持较高水平。m(GA3)/m(JA)在浸种1 d时达高值,4 d时最低;m(GA3+SA)/m(ABA+JA)随着浸种时间增加逐渐下降。18号浸种温度为25~30℃时对提高种子内源激素含量有着显著作用。【结论】横径显著影响种子形状,18号种子均匀度高且吸水率和吸水速率较为稳定;种子浸种后48 h吸水率和吸水速率达到稳定状态,促进萌发类激素含量升高。因此,浸种温度应在30℃下有利于种子萌发。研究结果可为油茶砧木标准化培育提供理论依据。

【Objective】This study investigated the seed characters ofCamellia oleiferaand analyzed the changes in water absorption and the absorption rate to explore changes in endogenous hormones during seed soaking and to provide a technical support for standardized rootstock cultivation. 【Method】Seeds ofC.oleiferacultivars: ‘Changlin 3’, ‘Changlin4’, ‘Changlin 18’, ‘Changlin 40’ and ‘Changlin 53’ were used in experiments to determine seed shape parameters and volume.In an artificial climate chamber with the fixed temperature and humidity, the water absorption and absorption rate at different times during seed soaking were determined for all the cultivars.In a separate experiment, Changlin18 was subjected to seed soaking at different times and temperatures and the concentrations of gibberellin(GA3), abscisic acid(ABA), salicylic acid(SA), and jasmonic acid(JA) were determined using LC-MS and compared by oneway ANOVA. 【Result】The seed volume was in the order as follows: Changlin 53, 40, 18, 3 and 4.Changlin 53 showed a significant variance in relation to the other cultivars.The three-dimensional coefficients of the seeds indicated that they were mostly flat for Changlin 3, 4 and 40 and nearly spherical for Changlin 18 and 53, which were significantly correlated with the transverse diameter length of the seeds.The seed volume of Changlin 3 and 4 was significantly or very significantly positively correlated with longitudinal and transverse diameters and there was a significant negative correlation with the cross diameter and seed volume between Changlin 40 and 53.There was significantly correlated with the seed volume between Changlin 40 and 53.The water absorption and absorption rate of each cultivar gradually stabilized after 48 h of seed soaking.Water absorption by Changlin 53 seeds was the highest than by Changlin 40 seeds, the lowest during 0-21 h of seed soaking.From 21-48 h of seed soaking, water absorption was in the order: Changlin 4, 3, 53,40 and 18.The water absorption rate of Changlin 40, 4, 3, 53 and 18was highest values within 10 h.There was no significant difference between cultivars in the germination rate(P<0.01 andP<0.05) after seed soaking, and the order was: Changlin 4, 40, 53, 3 and 18.The concentration of GA3 increased gradually after seed soaking in Changlin 18 and reached its highest value(0.39 mg tively, reached in 4 d.There were the highest values with 0.050 mg with 0.014 mg/kg in 4 d.During seed soaking, a continuously highm(GA3)/m(ABA) level was noted in 1 d and 4 d.The highest value form(GA3)/m(JA) were reached in 1 d and the lowest values in 4 d.The value form(GA3+ SA)/m(ABA+JA) decreased with an increase in seed soaking time.The soaking temperature for Changlin 18 was optimal from 25-30℃, and had a significant effect on improving the concentration of endogenous hormones. 【Conclusion】The shape of seeds ofC.oleiferacultivars was significantly affected by the transverse diameter.There was high uniformity in seeds of Changlin 18 which were stable in the water absorption and absorption rate.The water absorption and absorption rate reached stability after 48 h during seed soaking, which promoted high hormone concentrations for the germination of seeds.The seed soaking temperature was optimal for seed germination under 30℃. The results provide a theoretical basis for the standardized cultivation ofC.oleiferarootstock.