基于变温热处理与茎尖培养的花牛苹果砧木试管苗脱毒技术研究OA

[Objective]This study aimed to optimize the virus-free technology system for tissue-cultured rootstock seed-lings of Huaniu apples to obtain high-quality virus-free materials.[Methods]Tissue-cultured seedlings of seven Huaniu apple rootstocks,namely G935,Qingzhen 1,Huail Begonia,Xinjiang wild apple,Pingyitiancha,Wuqiqiuzi and Shandingzi,were used as experimental materials.The effects of heat treatment methods and duration on virus elimination efficiency were sys-tematically investigated.[Results]The results showed that the heat treatment method was a key factor affecting the survival rate and virus elimination efficiency of the tissue-cultured seedlings.A variable temperature treatment of 38℃with light for 10 hours followed by 32℃in darkness for 8 hours proved to be the most effective,achieving plant survival rates between 72%and 90%.Under the same heat treatment method,the inoculation site,whether shoot tip or lateral bud,had no significant im-pact on the survival rate.Based on this optimal variable temperature treatment,different treatment durations of 15,20,25,30,35,40 and 45 days were tested in combination with a secondary shoot tip excision and culture.The treatment duration of 35 days achieved the best virus elimination effect,with a virus-free rate of 75%to 100%for shoot tips.The virus elimination efficiency of shoot tips was significantly higher than that of lateral buds,which was only 38%,making the former more than twice as effective as the latter.[Conclusion]This study established an efficient virus-free protocol using a 35-day variable temperature treatment of 38℃with light for 10 hours followed by 32℃in darkness for 8 hours,combined with secondary shoot tip culture.Virus-free tissue-cultured seedling materials for all 7 rootstocks were successfully obtained.