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油樟(Cinnamomum longepaniculatum(Gamble)N.Chao ex H.W.Li),是樟科(Lauraceae)樟属(Cinnamomum)[1]香料植物[2]。油樟的枝、叶、根、果和花等部位均富含芳香精油,油樟叶中挥发油含量可达到3.8~4.5%[3],现已从油樟叶精油中鉴定出113余种化学成分[4]。因油樟具有良好的医用价值和芳香气味,现正受到人们越来越多的关注,其在香料、医药、和化学工业等领域也被广泛应用。油樟主要分布于四川宜宾,约占全国油樟资源85%、全世界油樟资源65%[5]。目前油樟主要通过扦插、嫁接、种子等多种类型繁殖[6],而扦插与嫁接存在诸多影响因素,目前油樟栽培以种子繁育为主。且目前油樟种植品种出油率差异明显,良种化程度不高。由于油樟母树缺乏,导致优良种子收集困难[7],而油樟试管苗易玻璃化,不利于工厂化育苗[8]。目前经过湿沙层积的油樟种子发芽率低,且沙藏后种子出苗差、活力弱、萌芽周期长,且保存有限。油樟种子的萌发及生长在一定程度上影响油樟种植与品质,因此通过解决油樟种子、种苗问题能够有效促进油樟经济的快速发展。
外源激素会影响种子的萌发 [9],赤霉素能够促进种子萌发[10]。赤霉素可以有效促进种子内水解酶的活性,增强种子活力[11],其不仅能够加速植物的生长和发育,还能够打破某些植物块茎、种子、鳞茎等器官的休眠,促进发芽[12]。不同浓度赤霉素对植物种子具有不同的效果,1~10 umol·L-1赤霉素可以有效缩短生菜种子培育期限[13],750~1 250 mg·L−1赤霉素处理36 h托鲁巴姆种子显著提高发芽势和发芽率[14],400 mg·L−1赤霉素显著提高白藤种子的发芽速度[15],200 mg·L−1赤霉素浸种增加色木槭的萌发率[16]。100 mg·L−1赤霉素浸泡6 h能有效促进枫香种子萌发[17]。
目前油樟研究主要集中在油樟精油成分[18]、油樟内生菌[19]、油樟油体外抑菌活性研究[20]及提高精油提取技术[21]等方面,而外源激素能否促进油樟种子萌芽以及种子萌芽过程中各项生理指标如何变化还未有深入研究。因此利用不同浓度赤霉素处理油樟种子,比较赤霉素处理后种子各项生理变化与形态学变化,并以此为基础筛选出能够有效促进油樟种子萌发的赤霉素浓度,缩短油樟种子萌发周期,提高油樟的成苗率,促进油樟优质种质资源筛选及丰富油樟苗木快速繁殖的理论基础。
Effects of Gibberellin with Different Concentrations on Physiological and Germination of Cinnamomum longepaniculatum Seeds
doi: 10.12172/202206300001
- Received Date: 2022-06-30
- Available Online: 2023-02-24
- Publish Date: 2023-06-25
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Key words:
- Gibberellin /
- Cinnamomum longepaniculatum seeds /
- Seed embryo /
- Physiological index
Abstract: Cinnamomum longepaniculatum is a second-class key protected plant in China, and it is also an economic forest rich in natural aromatic oil, which is unique to China. Currently, there were few studies on Cinnamomum longepaniculatum seeds, and there was no in-depth study on how the germination rate and physiological index of Cinnamomum longepaniculatum seeds change after gibberellin treatment. In order to promote the rapid germination of Cinnamomum longepaniculatum seeds, the plant growth regulator GAs was used to treat them. Through the determination of various physiological index and the observation of morphological structure, the theoretical basis of Cinnamomum longepaniculatum seeds germination could be further enriched. Taking Cinnamomum longepaniculatum seeds as the experimental materials, four concentrations of GAs (0.2 g·L−1, 0.4 g·L−1,0.6 g·L−1,1 g·L−1) treat the seeds for 24 h and 48 h, the physiological indexes and embryo development were compared. The results showed that 0.4 g·L−1 gibberellin treatment could significantly increase SOD and CAT activities, significantly decreased MDA content and significantly increased soluble protein content in Cinnamomum longepaniculatum seeds. The morphological development of embryos was obviously better than other treatments, and the endosperm cell connection density was smaller, the lipid droplets content was higher and the cell wall was thinner. Therefore, soaking seeds with 0.4 g·L−1GAs for 48 h was beneficial to promote the germination of Cinnamomum longepaniculatum seeds.