火龙果组培苗体细胞无性系变异及其分子检测  

Somaclonal variation of pitaya(Hylocereus undatus) in vitro plants and identification by molecular markers

作　　者：聂琼[1,2] 文晓鹏[1] 

机构地区：[1]贵州大学农业生物工程研究院.生命科学学院,贵阳550025 [2]贵州大学农学院,贵阳550025

出　　处：《果树学报》2017年第12期1527-1536,共10页Journal of Fruit Science

基　　金：国家自然科学基金(31560549;31760566)

摘　　要：【目的】了解火龙果离体快繁体细胞无性系的遗传稳定性,并揭示变异系间的遗传关系。【方法】以单粒种子萌发的丛芽扩繁第1代和第4代再生幼苗为材料,分析繁殖系数及棱的形态变化,并采用ISSR、SRAP和IRAP标记技术进行遗传变异分析。【结果】繁殖系数为14.9。快繁第4代试管苗中有3棱、4棱等6种形态学变异,其中5棱丛芽最多(50.54%),8棱丛芽最少(1%左右);3棱和4棱丛芽在RNA水平上(SRAP标记)表现出差异。24条ISSR引物、11对SRAP引物和17条IRAP引物在70个样品中共产生405条带,其中多态性带29条。扩繁第1代植株未发生DNA水平的变异,第4代植株的DNA条带出现了增加或缺失现象,植株变异频率为24.2%。16株变异株与原始植株(种子萌发植株)的遗传相似系数为0.77~0.97。在相似系数为0.90时,可将16个变异株分为4类,其中第Ⅰ类包括原始植株和12个变异株,第Ⅳ类与原始植株的差异最大,是GA3缺陷型矮化突变体。采用IRAP、SRAP、ISSR标记检测出的变异植株数量及多态性位点均存在差异。【结论】建立的火龙果快繁体系的繁殖系数为14.9,随快繁次数的增加,繁殖系数、生长势及遗传稳定性有下降的趋势。快繁第4代的体细胞无性系变异频率为24.2%,主要表现在DNA水平和棱茎形态上的变化。获得的16个变异株与原始植株的遗传相似系数为0.77~0.97,被分为4类,第Ⅳ类是GA3缺陷型矮化突变体。3棱和4棱丛芽差异可能是基因差异表达的结果。新开发的IRAP标记是检测火龙果无性系变异的有效手段。[Objective] Pitaya production has become a new, special and excellent agricultural project. Usually, propagation of pitaya is conducted by using cuttings from field plants. However, multiplication rates are low and it is difficult to obtain enough true-to-type plants for both plantation and research use. Tissue culture is the main means of rapid propagation of plants, and also a good method to obtain somaclonal variation. Currently, the shoots derived from a clone were used as the explants to study the rapid propagation in vitro. After rapid propagation of several cycles, the plants growth and morphological traits were different among some regenerated plants. To better apply the rapid propagation system and make further use of the variants, it is necessary to evaluate the genetic fidelity of the in vitro plants derived from the current rapid propagation system as well as to reveal the genetic relationship among the variants. [Methods] Pitaya shoots from single seed germination as explants were multiplied on Murashige and Skoog （MS） medium with 0.1 mmol. L-1 naphthalene acetic acid （NAA） and 2 mmol. L-1 6-benzyladenine （6-BA）, successively in vitro shoots were subcuhured for four cycles. Sixty-nine plantlets subcuhured for 1 and 4 cycles as well as their stock plant which primarily derived from a seed were used to analyze the morphological variations as well as propagation coefficient, and the genetic fidelity was identified by ISSR, SRAP and IRAP markers. NTSYS 2.01 software was further used to illustrate the variation plants. [ Results ]The propagation coefficient of the rapid micropropagation system was 14.9. The 4 derived shoots regenerated from a seedling characterized in 4 arris. Six arris types, i.e. 3-, 4-, 5-, 6-, 7- and 8-arris, of cluster buds were investigated in the regenerated plants successively subcuhured for 4 cycles, among which 5-arris buds were the most common, accounting for about 50.54% of the total, followed by the 4-arris buds which accounted for 27.2% of the total, and the 8-ar

关 键 词：火龙果 体细胞无性系变异 ISSR SRAP IRAP 

分 类 号：S667.9[农业科学—果树学]