甘薯脱毒及种薯(苗)繁育技术研究

Study on Virus⁃free and Seedling Propagation Techniques of Sweet Potato

中国是世界上最大的甘薯生产国,然而由于病毒病的存在,严重制约了甘薯产业的发展,建立通用的脱毒组培体系、高灵敏度的检测体系及高效的种薯(苗)繁育体系对甘薯产业发展具有重要意义。对12个主栽品种进行茎尖脱毒处理,建立了通用的脱毒组培体系MS+2 mg/L NAA+1.0 mg/L 6-BA,大多数品种的再生率在58%以上;获得SPFMV、SPCSV、SPLV、SPCFV和SPVG这5种病毒的特异性引物,该引物对病毒检测极限依次为10^(-6)、10^(-1)、10^(-4)、10^(-3)和10^(-3),具有较高的灵敏性;对脱毒品系进行筛选,获得优良脱毒株系甘12和粉薯2-2;建立脱毒种薯(苗)的三级繁育体系,即组培苗(一级)扩繁,温网室基质苗(二级)扦插扩繁和网棚大田苗(三级)繁育生产用种;进行洗苗速率(带根和不带根)对比试验,移栽方式(带根和不带根)与每孔移栽棵数(1~3棵)的双因素试验,结果表明不带根处理可显著提升洗苗速率,育苗前期每孔移栽棵数(1~3棵)在株高、茎粗、节间数方面无显著差异,带根处理前期生长具有优势,但二者成活率无显著差异,并不影响育苗结果。因此,该研究有利于甘薯病毒病防治、脱毒种薯(苗)推广和育苗成本的降低。

China is the largest sweet potato producer in the world.However,the development of the sweet potato industry is severely constrain⁃ed by viral diseases.The establishment of a universal virus⁃free tissue culture system,a highly sensitive detection system,and an efficient seed potato(seedling)breeding system are of great significance for the development of the sweet potato industry.A total of 12 main cultivars were subjected to shoot⁃tip virus elimination treatment using a universal tissue culture system MS+2 mg/L NAA+1.0 mg/L 6⁃BA,with regeneration rates of over 58%for most cultivars.Specific primers for five viruses,namely SPFMV,SPCSV,SPLV,SPCFV and SPVG,were obtained.The detection limits of these primers for the viruses were 10^(-6),10^(-1),10^(-4),10^(-3)and 10^(-3),respectively,indicating high sensitivity.Virus⁃free lines were selected,and excellent virus⁃free strains Gan 12 and Fenshu 2-2 were obtained.A three⁃tier breeding system for virus⁃free seed po⁃tatoes was established,including tissue culture seedlings(first tier),temperature⁃controlled greenhouse substrate seedlings(second tier)and field seedlings(third tier)for seed production.In addition,a comparison trial was conducted to evaluate the washing rate of seedlings(with roots and without roots),as well as a dual⁃factor experiment to assess transplanting methods(with roots and without roots)and the number of transplanted seedlings per hole(1-3 plants).Results showed that the treatment without roots significantly increased the washing rate of seed⁃lings.There were no significant differences in plant height,stem thickness,and internode number among groups with different numbers of transplanted seedlings(1-3 plants)during the early stage of seedling growth.The treatment with roots had advantages in early growth,but did not significantly affect the survival rate or the final result of seedling growth.Therefore,this study was beneficial for the prevention and control of sweet potato viral diseases,the promotion of virus⁃free seed potatoes,and the reduction of seedling production costs.