裸果木再生体系建立与不定芽发生研究

为探究裸果木再生体系建立的影响因素，确定其不定芽发生的起源，该研究以裸果木健壮植株的茎段为外植体，采用6 BA和IBA不同浓度组合，筛选愈伤增殖及不定芽再生的最佳浓度组合，确定生根诱导的关键影响因素，建立再生体系，并对其不定芽分化进程进行解剖结构分析，以确认其起源。结果表明：(1)裸果木茎段的最佳愈伤增殖培养基为MS+1 mg·L^-1 IBA+1 mg·L^-1 6 BA+30 g·L^-1蔗糖+7 g·L^-1琼脂，主体间效应分析表明IBA为关键影响因素；愈伤大小随IBA浓度增加呈现先升高后下降的趋势。(2)最佳不定芽诱导培养基为MS+0.5 mg·L^-1 6 BA+30 g·L^-1蔗糖+7 g·L^-1琼脂，诱导不定芽数量为4.9个/块，生芽率达92.3%。(3)生根诱导中，SH基本培养基和蔗糖浓度为关键因素，最佳生根培养基为SH+0~10 g·L^-1蔗糖+7 g·L^-1琼脂，生根率达91.3%。(4)解剖结构观察发现，不定芽起源于愈伤表层的分生细胞，为外起源。该研究通过器官发生途径建立了裸果木的再生体系，确定了不定芽为外起源，为裸果木这一珍稀濒危的林木种质资源保护及可持续利用奠定了研究基础，并为其未来的发展利用提供了有效途径。

Study on Establishment of Regeneration System and Adventitious Shoot Formation of Gymnocarpos przewalskii

In order to explore the influencing factors of the establishment of regeneration system of Gymnocarpos przewalskii and determine the origin of adventitious shoots, with the stem segments of the superior individual of G. przewalskii as explants, we used different concentrations of 6 BA and IBA to screen the optimal concentration combinations for callus proliferation and adventitious shoot regeneration in this study. The key influencing factors for rooting induction were determined, and the regeneration system was established. The differentiation process of adventitious shoots was analyzed to confirm its origin. The results showed that : (1) the optimal medium for callus proliferation was MS+1 mg·L^-1 IBA+1 mg·L^-1 6 BA+30 g·L^-1 sucrose+7 g·L^-1 agar. Inter subjectivity analysis showed that IBA was the key influencing factor. The callus size increased first and then decreased with the change of IBA concentration. (2) The best adventitious shoot induction medium was MS+0.5 mg·L^-1 6 BA+30 g·L^-1 sucrose+7 g·L^-1 agar, the number of adventitious shoots was 4.9 per piece, and the germination rate was 92.3%. (3) For rooting induction, SH basic medium and sucrose concentration were the key factors. The optimal rooting medium was SH+0-10 g·L^-1 sucrose+7 g·L^-1 agar, and the rooting rate was 91.3%. (4) Adventitious shoots originated from meristem cells on the surface of callus, which were exogenous. In this study, the regeneration system of G. przewalskii was established through organogenesis, and the adventitious shoots were identified as the external origin, which laid a foundation for the protection and sustainable utilization of G. przewalskii, a rare and endangered forest germplasm resource, and provided an effective way for its future development and utilization.