Abstract:
Worldwide, oak species are threatened with extinction due to habitat loss, pathogens, and changing fire regimes. Ex situ conservation through tissue culture may protect the remaining genetic diversity of Quercus dumosa, or the coastal sage scrub oak, from further loss. We designed three basal salt formulations based on the mineral composition of shoot tips and first leaves from mature Q. dumosa and explored carbohydrate source, stress-mitigating compounds, and plant growth regulator concentrations to develop a method of cultivating many Q. dumosa culture lines in vitro. All three novel basal salt formulations led to decreased necrosis compared with commercial basal salt formulas WPM, MS, and DKW. Substitution of 30 g L-1 sucrose with glucose and adding 250 mg L-1 ascorbic acid, 5.2 mg L-1 SNP sodium nitroprusside, and 103 mg L-1 y-aminobutyric acid improved culture health overall. In an experiment involving 115 culture lines, 0.66 mg L-1 6-benzylaminopurine produced the highest average shoots per explant, but 0.33 mg L-1 produced the greatest proportion of shoots 2 cm or greater. Incubation for 24 h in 20 mg L-1 indole-3-butyric acid led to the most rooting. These methods show promise for the ex situ conservation of many genotypes of endangered Q. dumosa.
摘要:
全球,由于栖息地的丧失,橡树物种面临灭绝的威胁,病原体,和改变消防制度。通过组织培养进行的异地保存可以保护橡树的剩余遗传多样性,或者沿海鼠尾草灌木丛橡树,从进一步的损失。我们根据成熟Q.dumosa的茎尖和第一片叶子的矿物质组成设计了三种基础盐配方,并探索了碳水化合物来源,缓解压力的化合物,和植物生长调节剂浓度,以开发一种在体外培养许多Q.dumosa培养品系的方法。与商业基础盐配方WPM相比,所有三种新型基础盐配方均导致坏死减少,MS,和DKW。用葡萄糖代替30gL-1蔗糖,并添加250mgL-1抗坏血酸,5.2mgL-1SNP硝普钠,和103mgL-1Y-氨基丁酸总体改善了文化健康。在一项涉及115个培养系的实验中,0.66mgL-16-苄基氨基嘌呤产生的每个外植体平均芽最高,但是0.33mgL-1产生的芽比例最大2cm或更大。在20mgL-1吲哚-3-丁酸中孵育24小时导致最生根。这些方法显示了对濒危Q.dumosa的许多基因型的异位保护的希望。