苹果品种和砧木组培苗对热处理脱毒的反应

Responses of Micropropagated Apple Cultivars and Stock to Thermotherapy for Viruses Elimination

通过不同的热处理方式并结合茎尖培养 ,比较了苹果品种和砧木组培苗对热处理脱毒的反应。实验结果表明 :不同苹果品种和砧木组培苗的耐热性不同 ,其中“富士”耐热性最强 ,小金海棠次之 ,“新红星”耐热性最差 ;变温热处理有利于延长苗木在处理期间的寿命 ,在 3种热处理时间下其死亡率均为 0 %。当茎尖在一定长度范围内 (约 1mm)时 ,茎尖成活率与试材、热处理方式、处理时间等无明显关系 ,而与培养温度等外界条件的关系密切。在相同处理条件下 ,不同试材其苹果潜隐病毒脱除率不同 ,小金海棠的脱毒率最高 ,“富士”次之 ,“新红星”第三 ;同时 ,不同病毒的被脱除率也不同 ,苹果褪绿叶斑病毒比苹果茎沟病毒更容易脱除。综合考虑苗木死亡率和脱毒率 ,对脱除小金海棠苹果褪绿叶斑病毒和苹果茎沟病毒 ,可采取 38℃恒温热处理 2 0d或 38 2 2℃变温处理 30d;对于“富士”,可采取 38℃恒温热处理 30d或 38 2 2℃变温处理30d以上 ;针对“新红星”耐热性差的特点 ,宜采用 38 2 2℃变温处理

Responses of apple cultivars and stock in vitro for viruses eli mination by different heat therapy regime in combination with tip propagation were studi ed The results showed that great differences were noted between materials in t h eir tolerance of heat Resistance of 'Fuji' was stronger than that of Malus x iao jinensis, and 'Stark Delicious' suffered from constant heat therapy However, D i urnal alternating temperature treatment availed to prolong survival rate of plan ts throughout the whole period of treatment, which led to 0% death rate When t h e length of shoot tips was about 1 mm, the percentage of viable apexes did not o b viously correlated with materials, regimes or days of heat therapy, but possibly correlated with its surround conditions such as temperature Rates of virus-el i mination under same treatment differed from plant to plant M xiaojinensis li st ed the top followed by 'Fuji', while 'Stark Delicious' ranked number three Howe ver, viruses were always inactivated in the same order: first apple chlorotic le af spot virus (ACLSV), followed by apple stem grooving virus (ASGV) Concerning about death rate of materials during heat treatment and virus elimination rate, 20-day constant heat treatment or 30-day alternating temperature therapy was eff ective for M xiaojinensis to eliminate ACLSV and ASGV Virus-free plant of ' Fuj i' favorite resulted from 30-day constant heat treatment or alternating tempera t ure therapy with treatment period of more than 30 days But for 'Stark Delicio us', an alternating temperature therapy regime was more suitable