Viral pathogens reduce the quality and yield of apple (Malus domestica) fruits by 30–50%. A mass production system of virus-free apple plantlets is needed to meet the demand of the domestic fruit tree industry. In this study, we compared the production of virus-free plants in different in vitro culture systems, including a temporary immersion bioreactor (TIB), a continuous immersion bioreactor, and conventional solid and liquid culture systems (controls). Apple plantlets were immersed in the TIB once every 3 h (TIB-3) or 6 h (TIB-6). The fresh weight of apple plants was the highest in the TIB-3 system and lowest in the liquid culture. Shoots were the longest in the TIB-3 system, approximately twofold longer than those in solid culture and liquid culture. Roots of apple plants were the longest in the TIB-3 system compared with solid and liquid cultures. Root number in the TIB-3 system was also higher than that in solid and liquid cultures. Moreover, leaf area was the highest in plants grown in the TIB-3 treatment. The total stem area of TIB-3 plants was the largest at 1.46 mm2. This study suggests that the airlift bioreactor is capable of producing a large number of virus-free plants in a short time compared with conventional culture systems. Additionally, secondary xylem was well developed in the stems of plants grown in the TIB-3 system. Therefore, this system shows a high potential for producing healthy plants suitable for acclimatization.

中文翻译：

---

使用临时浸入式生物反应器系统高效生产无病毒苹果苗

病毒病原体使苹果（苹果）果实的质量和产量降低 30-50%。满足国内果树产业的需求，需要一种无病毒苹果苗的大规模生产系统。在这项研究中，我们比较了不同体外培养系统中无病毒植物的生产，包括临时浸入式生物反应器 (TIB)、连续浸入式生物反应器和传统的固体和液体培养系统（对照）。苹果苗每 3 小时 (TIB-3) 或 6 小时 (TIB-6) 浸入 TIB 中一次。苹果植株鲜重在TIB-3系统中最高，在液体培养中最低。TIB-3 系统中的芽最长，比固体培养和液体培养中的芽长大约两倍。与固体和液体培养物相比，TIB-3 系统中苹果植株的根最长。TIB-3 系统中的根数也高于固体和液体培养物中的根数。此外，叶面积在 TIB-3 处理中生长的植物中最高。TIB-3 植物的总茎面积最大，为 1.46 mm2。这项研究表明，与传统培养系统相比，气升式生物反应器能够在短时间内生产大量无病毒植物。此外，在 TIB-3 系统中生长的植物茎中的次生木质部发育良好。因此，该系统显示出生产适合驯化的健康植物的巨大潜力。叶面积在 TIB-3 处理中生长的植物中最高。TIB-3 植物的总茎面积最大，为 1.46 mm2。这项研究表明，与传统培养系统相比，气升式生物反应器能够在短时间内生产大量无病毒植物。此外，在 TIB-3 系统中生长的植物茎中的次生木质部发育良好。因此，该系统显示出生产适合驯化的健康植物的巨大潜力。叶面积在 TIB-3 处理中生长的植物中最高。TIB-3 植物的总茎面积最大，为 1.46 mm2。这项研究表明，与传统培养系统相比，气升式生物反应器能够在短时间内生产大量无病毒植物。此外，在 TIB-3 系统中生长的植物茎中的次生木质部发育良好。因此，该系统显示出生产适合驯化的健康植物的巨大潜力。