Narváez Isabel, Martín Carmen, Jiménez-Díaz Rafael M, Mercado Jose A, Pliego-Alfaro Fernando
Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Departamento de Botánica y Fisiología Vegetal, Universidad de Málaga, Málaga, Spain.
Departamento de Biotecnología-Biología Vegetal, ETS Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Madrid, Spain.
Front Plant Sci. 2019 Nov 14;10:1471. doi: 10.3389/fpls.2019.01471. eCollection 2019.
Regeneration capacity, somatic embryogenesis, of four wild olive genotypes differing in their response to defoliating (resistant genotypes StopVert, OutVert, Ac-18 and the susceptible one, Ac-15) has been evaluated. To induce somatic embryogenesis, methodologies previously used in wild or cultivated olive were used. Results revealed the importance of genotype, explant type, and hormonal balance in the induction process. Use of apical buds obtained from micropropagated shoots following a methodology used in cultivated olive (4 days induction in liquid 1/2 MS medium supplemented with 30 µM TDZ-0.54 µM NAA, followed by 8 weeks in basal 1/2 MS medium) was adequate to obtain somatic embryos in two genotypes, StopVert and Ac-18, with a 5.0 and 2.5% induction rates, respectively; however, no embryogenic response was observed in the other two genotypes. Embryogenic cultures were transferred to basal ECO medium supplemented with 0.5 µM 2iP, 0.44 µM BA, and 0.25 µM indole-3-butyric acid (IBA) for further proliferation. Somatic embryos from StopVert were maturated and germinated achieving a 35.4% conversion rate. An analysis of genetic stability on StopVert, using Simple Sequence Repeats (SSRs) and Random Amplified Polymorphic DNA (RAPDs) markers, was carried out in embryogenic callus, plants regenerated from this callus and two controls, micropropagated shoots used as explant source, and the original mother plant. Polymorphism was only observed in the banding pattern generated by RAPDs in 1 of the 10 callus samples evaluated, resulting in a variation rate of 0.07%. This is the first time in which plants have been regenerated somatic embryogenesis in wild olive.
对四种野生橄榄基因型（对落叶反应不同，抗性基因型StopVert、OutVert、Ac - 18和易感基因型Ac - 15）的再生能力即体细胞胚胎发生进行了评估。为诱导体细胞胚胎发生，采用了先前在野生或栽培橄榄中使用的方法。结果揭示了基因型、外植体类型和激素平衡在诱导过程中的重要性。按照栽培橄榄中使用的方法（在添加30 μM噻苯隆 - 0.54 μM萘乙酸的液体1/2 MS培养基中诱导4天，随后在基础1/2 MS培养基中培养8周），使用从微繁殖芽获得的顶芽，足以在两种基因型StopVert和Ac - 18中获得体细胞胚胎，诱导率分别为5.0%和2.5%；然而，在其他两种基因型中未观察到胚性反应。将胚性培养物转移到添加0.5 μM 2 - 异戊烯腺嘌呤、0.44 μM苄氨基腺嘌呤和0.25 μM吲哚 - 3 - 丁酸（IBA）的基础ECO培养基中进行进一步增殖。StopVert的体细胞胚胎成熟并萌发，转化率达到35.4%。使用简单序列重复（SSR）和随机扩增多态性DNA（RAPD）标记对StopVert的遗传稳定性进行了分析，分析对象包括胚性愈伤组织、从该愈伤组织再生的植株以及两个对照，即用作外植体来源的微繁殖芽和原始母株。在所评估的10个愈伤组织样本中，仅在1个样本的RAPD产生的条带模式中观察到多态性，变异率为0.07%。这是首次通过体细胞胚胎发生在野生橄榄中再生植株。
