An EMS mutagenesis protocol for sugar beet and isolation of non-bolting mutants

An annual sugar beet line homozygous for the dominant gene for early bolting (B) has been mutagenized with different doses of ethylmeth‐anesulfonate (EMS). Approximately 15 000 M1 seeds were treated with EMS doses between 0.5 and 1% for 4, 6, 8, 12 and 14 h. Among 10 066 M1s, plants with chlorophyll defects and other abnormalities were found. Germination rates ranged between 30 and 100%, whereas the fertility of M1s dropped to 36%. A dose of 1% EMS applied for 8 h was found to yield an acceptable rate of M2 sterility (16%). Exactly 0.5% of the M2 families contained plants with altered bolting behaviour. After selfing these M2 plants, five non‐bolting M3 lines were selected. These plants do not exhibit shoot elongation even after cultivation under long‐day conditions. Thus, they are homozygous for new mutagenized, recessive non‐bolting alleles. Moreover, four M3 lines showed delayed bolting which was clearly different from the early bolting parent. This demonstrates varying activities of the bolting gene due to different mutational events.     

‘巴西蕉’离体芽的化学诱变和抗镰刀菌酸材料的筛选

在离体条件下,以我国主栽香蕉品种‘巴西蕉’(Musa AAA Cavendish)的多芽体和不定芽为材料,采用EMS和NaN3对其进行诱变处理,以镰刀菌酸毒素为选择压,筛选抗镰刀菌酸的材料。结果表明,EMS和NaN3诱变处理多芽体适宜的浓度和时间组合分别为1.6%+3h和2g/L+3h,NaN3诱变处理不定芽适宜的浓度和时间组合为2g/L+1h。镰刀菌酸毒素筛选多芽体和不定芽适宜浓度范围分别为36～45mg/L和10～20mg/L,筛选获得的多芽体和不定芽多次继代培养后仍保持对镰刀菌酸的抗性。本研究可为香蕉抗枯萎病育种提供有价值的材料和技术参考。     

耐三唑并嘧啶类除草剂花生种质创制与鉴定

目前耐除草剂花生的种质资源匮乏,这制约了花生栽培模式的多元化发展。为创制耐不同除草剂的花生种质资源,我们利用甲基磺酸乙酯诱变技术创建了一个由55,000多个花生株系组成的诱变群体,随后选择多种不同除草剂对该群体进行筛选,获得多个对不同除草剂具有耐性的花生突变体。其中一个突变体在田间叶面喷施处理和多种实验室条件下的除草剂耐受性评估试验中均表现出对唑嘧磺草胺和双氟磺草胺极强的耐性,但这种耐性性状并未对花生的产量与品质产生不良影响。为明确这种性状是否与除草剂靶标抗性相关联,我们比较分析了该突变体与野生型中这2种除草剂靶标酶(乙酰羟酸合酶,AHAS)的基因序列及其表达量的差异。分子克隆与序列分析显示,花生A10与B10染色体上各含一个与拟南芥AtAHAS序列高度相似的基因,分别命名为AhAHAS1a与AhAHAS1b。花生A08与B08染色体上亦各含一个AHAS基因,分别命名为AhAHAS2a与AhAHAS2b。然而,与野生型相比,突变体中的这些基因并未发生能够致使氨基酸序列发生改变的核苷酸替换。进而发现, AhAHAS基因的表达量在突变体与野生型中没有显著差异。这些结果表明,该花生突变体的除...