Key message

Providing an improved protocol for cloning of Picea abies (L.) H. Karst. mature trees via Agrobacterium rhizogenes.

Abstract

In reforestation programs, rejuvenation of superior genotypes is of great importance in helping juvenile rootstock production. In this regard, the use of plant tissue culture to produce axillary and/or adventitious shoots from explants of mature trees has been the objective of many researchers. There are a few reports about the successful in vitro rooting of the regenerated shoots from explants of mature trees. There is a very low rate of natural rooting in conifers, between 1 and 5%. Furthermore, they are still hard to root even when auxins are applied. In this study, in vitro propagation of Norway spruce explants and its rooting improvement by A. rhizogenes with the aim of receiving an efficient clonal propagation method was investigated. The effects of BA (0.5, 1, 1.5, and 2 μM) and TDZ (0.0025, 0.025, 0.25, and 2.5 μM) were examined on axillary shoot development from shoot-tip explants of the Norway spruce. The effects of three strains of Agrobacterium rhizogenes (K599, AR15834 and GMI9534) were also examined on enhancement of the root induction. According to the results, after the treatment of 1.5 μM BA, 87.5% of shoot-tip explants produced axillary shoots (the highest percentage among treatments), and also the maximum mean number of regenerated shoots per explant (6.5) was achieved in this treatment. Furthermore, the induction of rooting was performed using IBA (7.5 µM) and IAA (0.5 or 1 μM) in the WPM medium along with keeping the explants in the darkness at 21 °C, which yielded 37.5% and 12.5% rooting, respectively. Moreover, the application of coumarin along with IAA caused an increase of 22% in rooting, compared to the use of IAA alone. Two strains, K599 and AR15834, succeeded in improving the percentage of rooting, with the highest being 54.2% as a result of using the K599 strain alongside 7.5 μM IBA. The proposed treatment can be used efficiently for the propagation of Norway spruce in landscaping and/or reforestation programs.

中文翻译：

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控制克隆成熟云杉冷杉（L.）H. Karst的障碍。通过组织培养并与发根农杆菌共培养

关键信息

提供了用于克隆云杉（L.）H.Karst的改进方案。通过发根农杆菌成熟的树木。

抽象

在重新造林计划中，使优良基因型恢复活力对于帮助少年砧木生产极为重要。在这方面，使用植物组织培养物从成熟树的外植体产生腋生和/或不定芽是许多研究人员的目标。关于成熟树木外植体再生芽的成功生根的报道很少。针叶树的自然生根率非常低，在1-5％之间。此外，即使使用了生长素，它们仍然很难生根。在这项研究中，挪威云杉外植体的体外繁殖及其发根土壤杆菌的生根改良目的是研究一种有效的克隆繁殖方法。研究了BA（0.5、1、1.5和2μM）和TDZ（0.0025、0.025、0.25和2.5μM）对挪威云杉芽尖外植体腋芽发育的影响。三种发根农杆菌菌株的作用（K599，AR15834和GMI9534）也进行了根诱导增强研究。根据结果​​，在1.5μMBA处理后，有87.5％的芽尖外植体产生腋生芽（在处理中百分比最高），并且在该处理中也达到了最大平均外植体再生芽数（6.5）。 。此外，在WPM培养基中使用IBA（7.5 µM）和IAA（0.5或1μM）进行生根诱导，同时使外植体在黑暗中于21°C保持生根，分别产生37.5％和12.5％的生根。此外，与单独使用IAA相比，香豆素与IAA一起使用可使生根增加22％。K599和AR15834这两个菌株成功地提高了生根率，由于将K599菌株与7并用，因此最高，达到了54.2％。5μMIBA。拟议的处理方法可以有效地用于美化和/或造林计划中挪威云杉的繁殖。