^(60)Co-γ射线对枳生物性状和分子特性的影响

Effect of ^(60)Co-γ rays on Physiological Index and Molecule Characteristic of Poncirus trifoliata

为探究60Co-γ射线辐照处理对枳的生物性状和分子特性的影响,本研究采用不同剂量的60Co-γ射线辐照处理枳种子,萌芽后测定枳苗部分生物性状,并采用ISSR分子标记进行检测。结果表明:低剂量处理可促进种子萌发,而高剂量处理的种子出苗率明显下降;幼苗平均高度差异较小;枳半致死剂量为120 Gy;通过半致死剂量辐照的枳苗在叶片、刺、株型等方面出现较大的变化;在水分胁迫下,半致死剂量辐照的枳苗脯氨酸含量存在较大差异,含量为358.16~1 372.96μg·g-1;ISSR分析结果表明,经过120Gy辐照获得的枳苗在DNA水平上存在明显的多态性差异。本文为柑橘砧木选育及筛选与干旱胁迫相关的枳突变体提供了理论依据。

In order to investigate the effect of 60 Co-γrays treatment on the physiological index and molecule characteristic of Poncirus trifoliata, and to discover mutants that related to drought stress. The seeds were irradiated by different dose of 60 Co-γ-rays. After germination, the number of seedling emergence and the height of Poncirus trifoliate seedlings were measured, polymorphisms among those seedlings were analyzed with ISSR molecular markers, and the proline content of leaves under drought stress were detected. The results indicated that the seeds gerimination can be promoted by low irradiation dose, but inhibited by high irradiation dose. The average seedling heights irradiated by different dose of 60Coγ-rays were similar. Irradiated by semi-lethal dose, which was 120Gy, the seedlings showed more variances among the leaves, thorns and plant types of Poncirus trifoliata when compared with CK. Under drought stress, the content of proline in seedlings irradiated by 120Gy changed from 358.16μg·g-1 to 1 372.96μg·g-1 The result of ISSR analysis showed that there were obvious polymorphisms among the seedlings irradiated by 120Gy irradiation dose. This paper prorides the research foundation for citrus rootstock breeding and screening of drought-tolerant mutants of Poncirus trifoliata.