苹果耐重茬砧木优系多倍体诱导及鉴定

Polyploid Induction a nd Identification of Apple Rootstocks with Tolerance to Continuous Cropping

为了探讨适宜的苹果耐重茬砧木多倍体诱导技术体系,本研究以前期筛选出的耐重茬砧木株系12-2的组培苗为主要供试材料,通过秋水仙碱浸渍和混培法、不同配置培养基及不同培养材料,进行多倍体诱导,比较不同方法组合后代的诱变率和存活率,并以流式细胞仪鉴定方法进行鉴定。结果表明:秋水仙碱浸渍法处理茎段过程中发现浓度在30 mg/L处理24 h时的存活率最高,达74.3%,但未获得变异材料,在50 mg/L处理48 h时获得1株变异材料,诱变率达2.9%;利用混培法处理茎段时发现,50 mg/L处理获得2株多倍体材料,1株为纯合四倍体,1株为嵌合体,诱导率为5.8%,70 mg/L处理也获得1株嵌合体材料;30 g/L的蔗糖处理诱导后的不定芽数最多,不定芽再生率最高达68.6%,也明显高于其他碳源山梨醇和葡萄糖的处理结果,并获得2株变异株;MS培养基的不定芽再生率达68.6%,变异株2株,变异率为2.9%,在不同培养基处理中效果最佳;三种生长素IAA、NAA、IBA均获得变异株,其中IAA和NAA处理分别获得1株变异株,IBA处理获得2株;N1在四种培养材料(12-2,31,N1,N2)中诱导结果最为突出,获得2株变异材料。最终共获得17株变异材料,其中1株为纯合四倍体,其余均为嵌合体。本研究结果为苹果耐重茬砧木多倍体诱导技术体系提供了理论支撑。

In order to explore the suitable polyploid induction technology system of apple continuous cropping rootstock,the tissue culture seedlings of 12-2,which was selected as the main test material,were induced by colchicine immersion and mixed culture,different media and different culture materials.The mutation rate and survival rate of different combinations were compared and analyzed by flow cytometry.The method was used for identification.The results showed that:in the process of colchicine soaking treatment of stem segments,the highest survival rate was 74.3%when the concentration of colchicine was 30 mg/L for 24 h,but no mutant material was obtained,one mutant material was obtained when the concentration of colchicine was 50 mg/L for 48 h,and the mutation rate was 2.9%;in the process of colchicine soaking treatment of stem segments,it was found that two polyploid materials were obtained when the concentration of colchicine was 50 mg/L,one was homozygous tetraploid,one was chimeric,and the induction rate was 5.8%.The results showed that the highest number of adventitious buds and the highest regeneration rate of adventitious buds was 68.6%in 30 g/L sucrose treatment,which was also significantly higher than that in other carbon sources such as sorbitol and glucose treatment,and two mutants were obtained;the regeneration rate of adventitious buds in MS medium was 68.6%and two mutants were2.9%,which was the best in different medium treatments;mutant strains were obtained from IAA,NAA and IBA,one mutant strain was obtained from IAA and NAA treatment respectively,and two strains were obtained from I BA treatment;N1 was the most prominent among the four culture materials(12-2,31,N1,N2),and two mutant strains were obtained.Finally,a total of 17 mutant materials were obtained,one of which was homozygous tetraploid,and the others were chimeric.This study provided theoretical support for the polyploid induction technology system of apple rootstocks with continuous cropping tolerance.