离体筛选甘蓝抗性变异体及其生化特性研究

利用多步正筛选系统 ,以不同剂量的60 Coγ -射线对甘蓝离体再生不定芽进行诱变处理 ,处理后的无性系经连续多代离体筛选后 ,获得了甘蓝抗性变异体C4 - 6K ,C4 - 8K ,C4 - 12K ,再生植株。甘蓝抗性变异体对HYP表现抗性 ,且抗性保持相对稳定 ;变异体游离脯氨酸的含量比野生型有了很大的提高 ;游离氨基酸总量亦较野生型高 ,且多种游离氨基酸的含量发生变化 ,除胱氨酸含量微少 ,天冬氨酸、甘氨酸、蛋氨酸、酪氨酸、苯丙氨酸的含量较野生型有所下降外 ,其他 11种游离氨基酸的含量均有不同程度的提高 ,以精氨酸、脯氨酸、丙氨酸的含量增加最为明显。在水分胁迫、盐分胁迫、高温胁迫等逆境条件下 ,甘蓝抗性变异体表现出比野生型更耐旱、耐盐 ,变异体和野生型对高温胁迫表现的抗性差异不大 ;SOD ,POD活性均高于野生型 ;MDA含量较野生型低 ,以上的情况表明变异体比野生型有更强的抗逆性

In vitro Selection of Resistant Variant of Cabbage and Its Characteristics

By means of the multi-step direct selection system,the regenerated adventitious buds of cabbage were submitted to different dose 60Co γ-ray irradiations.Regenerated plants of variant lines resistant to hydroxy-L-proline have been obtained,disignated as C4-6K,C4-8K,C4-12K,an regenerated shoots and plants of hydroxy-L-proline-resistant variant resist to hydroxy-L-proline,The content of proline of resistant variant is much higher than that of wild type,the content of total amino acids is higher than that of wild type.Except trace cystine,aspartic acid,glycine,methionine,tyosine and phenylanine,the other eleven kinds of amino acid increased,especial the content of arginine,proline and alanine in creased most significantly.Under water,salt and high temperature stress,the tolerance of hydroxy-L-proline-resistant variant of cabbage to drought and salt was stronger than those of wild type,and their response to high temperature stress is not signifficant.But with the high temperature stress degree,proline accumulation in variant increased first,then decreased.The activity of superoxide dismutase(SOD) and peroxidase(POD) in the variant of cabbage are higher than those in wild type,and the content of melonaldehyde(MDA) in variant of cabbage is less than that in wild type,it indicated that the stress-resistance of variant is stronger than that of wild type.