柑橘品种茎段离体培养条件的优化及微芽嫁接试验

【目的】优化柑橘品种茎段离体培养条件并开展微芽嫁接(试管内茎尖嫁接)试验,为培育无毒柑橘组培种苗提供参考依据。【方法】对温州蜜柑和纽荷尔脐橙成年态枝条进行不同浓度HgCl_2和NaClO消毒,筛选适宜组培利用的柑橘外植体消毒方式、采集季节及激素配比;开展嫁接砧木种子消毒和微芽嫁接试验,分析两个柑橘品种微芽嫁接的萌发状况。【结果】温州蜜柑外植体的最适消毒方法为70%酒精+1.0‰HgCl_2消毒6 min处理两次;纽荷尔脐橙外植体的最佳消毒方法为70%酒精+15.0%NaClO处理两次;采集成年态柑橘茎段进行离体培养的最佳时期为夏季;在MS固体培养基中添加1.0 mg/L 6-苄氨基嘌呤(6-BA)和0.1 mg/L萘乙酸(NAA)均有利于两个柑橘品种外植体腋芽萌发。砧木种子最适消毒方法为剥去内外种皮+70%酒精+1.5%NaClO溶液处理;两个柑橘品种微芽嫁接的萌发率较低,分别为10.00%和6.67%,但嫁接成功后柑橘苗长势良好。【结论】于夏季剪取温州蜜柑和纽荷尔脐橙成年态枝条带芽茎段,分别经70%酒精+1.0‰HgCl_2消毒6 min处理两次、70%酒精+15.0%NaClO处理两次,在添加1.0 mg/L6-BA+0.1 mg/L NAA的MS固体培养基中接种,可获得最佳的培养效果。利用微芽嫁接技术嫁接的柑橘苗长势良好,可在提高其嫁接萌发率基础上推广应用。

Optimization of citrus stem culture conditions in vitro and experiment of shoot-tip grafting

Objective]Citrus stem culture conditions in vitro was explored and the shoot-tip grafting(stem tip grafting in tube)was carried out which could provide reference for cultivating virus-free citrus culture seedling.Method]The mature stems of Satsuma mandarin and Newhall navel orange were disinfected with different concentrations of HgCl2 and NaClO. The disinfection methods of citrus explants suitable for tissue culture,collecting season and hormone ratio were screened. The rootstock seed disinfection and the shoot-tip grafting were carried out to analyze germination status of grafted shoot-tips for the two varieties.Result]The optimum disinfection method for S. mandarin explants was treated with 70% alcohol+1.0‰ HgCl2 for 6 min for 2 times. The optimum disinfection method for Newhall navel orange explants was 70% alcohol+15.0% NaClO solution for 2 times. The optimum citrus stem collecting period for culture in vitro was summer. Added 1.0 mg/L 6-benayl aminopuring(6-BA)and 0.1 mg/L naphthylacetic acid(NAA)in MS solid medium were beneficial to the germination of axillary buds for the two citrus varieties. The optimum disinfection method for rootstock seed was removing the inner and outer seed coat+70% alcohol+1.5% NaClO solution. The germination rate of the two varieties were low,which were 10.00% and 6.67% respectively,but citrus seedlings grew well after successful grafting.Conclusion]The mature stems with buds are harvested in summer and S. mandarin stems were disinfected with 70% alcohol+1.0‰ HgCl2 for 6 min for 2 times;and Newhall navel orange were treated with 70% alcohol+15.0% NaClO solution for 2 times. Then they are cultured in MS solid medium supplemented with 1.0 mg/L 6-BA+0.1 mg/L NAA. This method can achieve good culture effects. The citrus seedlings grafted with shoot-tip grow well. Therefore,this method can be used after improving the graft germination rate on this basis.