叠氮化钠处理纽荷尔脐橙腋芽的诱变效应研究

Study on the Mutagen Effect of NaN_3 in Axillary Bud of Newhall Navel Orange(Citrus sinensis Osbeck)

芽变选种在柑橘品种选育中占有重要地位,但是在自然条件下柑橘的自发变异率较低;本研究利用叠氮化钠(Na N3)处理纽荷尔脐橙枝条腋芽,通过分析处理条件下枝条的存活率与观察枝条腋芽处新生长出的枝叶形态有无变异,探索Na N3处理柑橘腋芽的诱变效应和方法,以期为研发柑橘芽变创制技术提供实验证据。实验结果显示:当Na N3浓度≤5 mmol/L,纽荷尔脐橙枝条的存活率为86.7%~100%;Na N3浓度为10 mmol/L,处理时间为3 h时纽荷尔脐橙枝条的存活率为64%、处理时间为24 h时纽荷尔脐橙枝条的存活率为51.7%;观察Na N3处理后枝条腋芽处生发出的新梢枝叶形态发现,一些叶片形态发生了变化,并且变异叶片在枝条上生长的位置毗邻;利用SRAP分子标记检测出一些新梢变异叶片的基因组DNA发生了变化。本研究结果表明,化学诱变剂Na N3处理纽荷尔脐橙枝条能够对腋芽产生诱变效应,5~10 mmol/L的Na N3浓度、处理时间24 h的诱变方法可适用于纽荷尔脐橙枝条腋芽诱变工作。

Though the spontaneous mutation rates are low under natural conditions, bud mutations have been an important way to select new varieties in Citrus. In this study, we treated Citrus axillary bud by Na N3. Though analyzing and treating Citrus bud mutation probability and investigating the changes of the newborn foliage morphology, we tested the mutation effect and method of Na N3 on Citrus axillary bud in order to provide the experimental evidence for studying the new technology. Experimental results show that, when Na N3 was supplied at concentrations lower than 5 mmol/L, 86.7%~100% plants survived. When the concentration of Na N3 was raised up to 10 mmol/L, the plant survival rate was 64% with a 3 h treatment, and survival rate decreased to 51.7% when treating time lasted to 24 h. On survival plants, we observed some irregular shape leaves adjacent to each other,and found some changes in DNA structure of mutant leaves using SRAP molecular markers. This study suggests that Na N3 has mutation effect on Citrus bud, and 5~10 mmol/L Na N3 with 24 h treatment time should be suitable for creating mutation in Newhall Navel Orange.