摘要：本试验对SCoT反应体系进行优化,并筛选合适的引物,然后对24份试材进行SCoT标记,获得的目的片段克隆测序,通过测序结果探讨其遗传变异;结果表明,甜橙SCoT标记的20μL优化反应体系为:DNA模板80ng,Mg2+浓度1.6mmol/L,dNTPs浓度0.3mmol/L,引物浓度0.2μmol/L,Taq DNA聚合酶用量1.6U,扩增产物在100～2000bp之间,扩增条带明亮清晰,反应体系具有良好的稳定性和可重复性。24份试材的测序片段的大小为1090～1091bp,一致性达到99.84%,存在单碱基的缺失与替换,BLAST结果显示,该序列的编码蛋白质与核糖体蛋白S3的N端同源性高;利用单碱基变异可以区分其中的12个甜橙变异株系和'安江香柚',其他变异株系还需要结合其他的分子标记技术来进行鉴别,有待进一步研究。

摘要：[Objective] The aim was to identify genetic variation in Citrus sinensis （sweet orange） germplasm from Hunan Province according to the Start Codon Targeted （SCoT） Polymorphism. [Method] The reaction system for SCoT amplification from sweet orange was first optimized, and then the SCoT fragments were amplified from 24 sweet orange cultivars collected in Hunan Province and sequenced for genetic variation analysis. [Result] The optimum reaction system for SCoT markers amplification was 2.0 μl containing 80 ng of template DNA, 0.3 mmol/L dNTPs, 0.2 μmol/L primer, 1.6 mmol/L Mg2＋, 1.6 U of Taq DNA polymerase and 10×PCR buffer. By using this reaction system, the PCR products from the sweet orange cultivars produced clear and reproducible bands at 100-2 000 bp through electrophoresis. The SCoT fragments of the 24 sweet orange cultivars were 1 090-1 091 bp, with the homology of 99.84% and nucleotide deletion and substitution. After being sequenced, the SCoT polymorphisms could distinguish 12 sweet orange cultivars. In addition, the BLAST result showed that part of the SCoT fragments coding region shared high homology with ribosomal protein S3 N superfamily. [Conclusion] This study will provide a theoretical basis for breeding sweet orange cultivars.

摘要：用本试验设计改装的控温冰箱对2年生的枳(PoncirustrifoliataRaf.)和宫本/枳砧(***)营养袋盆栽苗进行低温处理,探讨枳和宫本生长期的致死低温.结果表明,棉絮包蔸保持土温的效果与低温处理时间呈极显著正相关,相关系数为r=0.9624.枳和宫本致死低温处理分别为-6℃60min和-6℃40min左右,即该处理导致枳和宫本春叶冻死,电解质渗出率陡然成倍增加,丙二醛含量出现最大值,枳叶片中丙二醛含量比对照增加了14.81%,宫本叶片中丙二醛含量较对照增加17.58%.枳叶片中丙二醛含量从对照到各处理平均是宫本的2.1倍.