单倍体甜瓜染色体加倍技术研究

高宁宁 李晓慧 康利允 梁慎 常高正 李海伦 王慧颖 王琰 徐小利 赵卫星

摘    要：探究秋水仙素对甜瓜单倍体加倍的影响，以便为甜瓜遗传育种研究提供新材料。以甜瓜大孢子离体培养获得的单倍体为试材，利用不同浓度秋水仙素直接加入培养基和浸芽后接种到芽伸长培养基两种方法进行甜瓜单倍体的加倍试验。70 mg·L-1秋水仙素直接加入培养基加倍频率最高为37%，组培苗成活率为67%，700 mg·L-1秋水仙素附加1.5% DMSO浸芽处理2 h加倍频率最高可达58%，成活率为100%。在不添加秋水仙素的培养基中，添加0.2 mg·L-1 KT加倍率为8%～17%，表明激素KT也能诱导单倍体植株加倍。加倍植株经流式细胞仪倍性鉴定，发现除存在单倍体、二倍体外，还存在混倍体，100 mg·L-1秋水仙素浸芽处理6 h嵌合体的比例最高为75%。结果表明，秋水仙素浸芽处理效果好于直接加入培养基，700 mg·L-1秋水仙素浸芽处理2 h加倍频率最高为58%。

关键词：甜瓜;单倍体;秋水仙素;染色体加倍

中图分类号：S652 文献标志码：A 文章编号：1673-2871（2021）06-028-05

Study on chromosome doubling technique of haploid muskmelon

GAO Ningning， LI Xiaohui， KANG Liyun， LIANG Shen， CHANG Gaozheng， LI Hailun， WANG Huiying， WANG Yan， XU Xiaoli， ZHAO Weixing

（Henan Academy of Agricultural Sciences， Horticulture Institute， Zhengzhou 450002， Henan， China）

Abstract： In order to explore the effect of colchicine on haploid doubling of muskmelon and provide new materials for the genetic and breeding research， the haploid muskmelon obtained from megaspore culture in vitro was used as the test material. The haploid doubling test of muskmelon was conduced by adding colchicine with different concentrations to the medium and immersing the buds with colchicine then inoculated into the medium of bud elongation. The maximum doubling frequency of 70 mg·L-1 colchicine directly added to the medium was 37%， and the survival rate of tissue cultured seedling was 67%. The maximum doubling frequency of 700 mg·L-1 colchicine plus 1.5% DMSO immersing buds for 2 h was up to 58%， and the survival rate was 100%. The doubling rate of adding 0.2 mg·L-1 KT to the medium without colchicine was 8%-17%， which indicated that KT could also induce the doubling of haploid plants. In addition to haploid and diploid plants， there were also mixoploid plants by flow cytometry identification. The proportion of chimeras was the highest， up to 75% by immersing buds in 100 mg·L-1 colchicine solution for 6 h. The results suggested that the effect of colchicine immersing buds was better than that of adding directly into the medium， and the doubling frequency was the highest， up to 58% by immersing buds in 700 mg·L-1 colchicine solution for 2 h.

Key words： Muskmelon; Haploid; Colchicine; Chromosome doubling

甜瓜（Cucumis melo L.）屬于葫芦科，是世界十大水果之一，我国拥有丰富的甜瓜资源，但遗传基础狭窄。利用常规育种手段进行甜瓜品种改良的周期长且效率低，单倍体材料的基因型和表现型完全一致，经过染色体加倍后可产生纯合的二倍体植株，利用单倍体诱导技术可大大提高育种效率，缩短育种周期。另外，纯系群体具有重要的遗传学研究价值，可应用于基因定位、克隆以及遗传图谱的构建等。单倍体植株可以通过人工诱导获得，也可以自发产生，但在自然界中自发产生单倍体的频率极低[1]。……