ABSTRACT Pecan, [Carya illinoinensis (Wangenheim) C. Koch] is a nut crop of growing worldwide interest and importance. In this research, a micropropagation protocol was developed during 2015–2016 using five pecan cultivars (‘GraTex’, ‘Wichita’, ‘Choctaw’, ‘10 J’ and ‘GraKing’). In the establishment phase, nodal segments of mature pecan trees were collected 9, 13, 17, 21, and 25 days after bud-break and maintained at 4°C for 0, 24, 48, or 72 hours. Next, they were soaked in 2.5% sodium hypochlorite for 1, 2, 3, 4, 5, 6, or 7 minutes. Each explant was cultured on DKW medium individually. For proliferation phase, the best established shoots were cut into nodal segments and cultured on DKW medium supplemented with different BA concentrations (4.44, 13.30, 22.20, and 44.40 µM). Proliferating cultures were established and microshoots were rooted on MS medium containing IBA (4.9, 14.7, 24.5, and 49.0 µM) for 6 days in the dark. Date of cutting field-grown shoots for explanting had a significant effect on disinfection and culture establishment, with optimum success 11–15 days after bud break. Preliminary chilling treatment (4°C for 48 h) prior to cutting into nodal segments improved explant establishment. The best proliferation rate was obtained using 22.2 µM BA. Root induction using 24.5 µM IBA gave the highest rooting percentage. Rooted microshoots were successfully transferred to pots. Although the ‘Wichita’ and ‘10 J’ cultivars had the highest success for acclimatization (89% and 84% respectively) the difference between cultivars was not significant and plantlets of five pecan cultivars were successfully acclimated. The results of this research can be applied by the authors in commercial level.

中文翻译：

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商业山核桃品种微繁研究进展

摘要 山核桃 [Carya illinoinensis (Wangenheim) C. Koch] 是一种日益受到全球关注和重要性的坚果作物。在这项研究中，2015-2016 年期间使用五种山核桃品种（'GraTex'、'Wichita'、'Choctaw'、'10 J' 和 'GraKing'）开发了微繁殖协议。在建立阶段，在萌芽后 9、13、17、21 和 25 天收集成熟山核桃树的节段，并在 4°C 下保持 0、24、48 或 72 小时。接下来，将它们浸泡在 2.5% 次氯酸钠中 1、2、3、4、5、6 或 7 分钟。每个外植体在 DKW 培养基上单独培养。对于增殖阶段，最好的芽被切成节段，并在补充有不同 BA 浓度（4.44、13.30、22.20 和 44.40 µM）的 DKW 培养基上培养。建立增殖培养物，并将微芽在含有 IBA（4.9、14.7、24.5 和 49.0 µM）的 MS 培养基上在黑暗中生根 6 天。外植芽的剪枝日期对消毒和培养建立有显着影响，在萌芽后 11-15 天取得最佳成功。在切割成节段之前的初步冷却处理（4°C 48 小时）改善了外植体的建立。使用 22.2 µM BA 获得最佳增殖率。使用 24.5 µM IBA 的根诱导产生最高的生根百分比。已生根的微芽成功转移到盆中。尽管 'Wichita' 和 '10 J' 品种驯化成功率最高（分别为 89% 和 84%），但品种之间的差异并不显着，5 个山核桃品种的幼苗成功驯化。