贵州濒危树种岩生红豆种子萌发特性研究

Study on Seed Germination Characteristics of Endangered Tree Species Ormosia saxatilis in Guizhou Province

为探讨岩生红豆种子萌发特性及影响种子萌发的限制因子,进行了岩生红豆种子的物理性状和吸水性测定,开展了岩生红豆种子种皮预处理和发芽温度处理2个组合的试验研究,并对其种皮和种胚的甲醇浸提液进行了生物测定。结果表明:岩生红豆种子存在休眠现象,其种皮坚硬致密,透水透气性差,用小刀划伤种子种皮后能有效改善种皮的透性,其96 h累计吸水率达63.63%,比未做处理的种子增加60.56%。去皮处理的岩生红豆种子发芽率最高,达45.5%,比未去皮处理的种子发芽率高25.7%。岩生红豆萌发受到种皮限制,以去除种皮和变温25℃/20℃处理组合发芽效果最好,发芽率高达61.0%。岩生红豆种皮浸提液和种胚浸提液均对白菜种子的萌发具有抑制作用,随着浓度的增加,萌发抑制率逐渐增大,种子发芽率逐渐降低。其中种皮浸提液的抑制作用明显高于种胚,与对照组相比,用0.01 g·mL^(−1)、0.05 g·mL^(−1)和0.1 g·mL^(−1)种皮甲醇浸提液处理的白菜种子发芽率降低了20.0%、42.0%和64.0%,萌发抑制率增加了25.6%、53.9%和84.6%;初步认为,导致岩生红豆种子休眠的原因是种皮透性差,种皮和种胚含有抑制物质。

In order to explore the germination characteristics of Ormosia saxatilis seeds and limiting factors affecting seed germination,the physical properties and water absorption of Ormosia saxatilis seeds were measured,and two combinations of seed coat pretreatment and germination temperature treatment were carried out,and the methanol extracts of seed coat and embryo were measured by bioassay.The results showed that the seeds of Ormosia saxatilis were dormant,and the seed coat was hard and compact,less permeable breathability.Scratching the Ormosia saxatilis seed coat with a knife could effectively improve the permeability of the seed coat,and the cumulative water absorption rate in 96 h reached 63.63%,which was 60.56%higher than that of untreated seeds.The germination rate of peeled Ormosia saxatilis seeds was the highest,reaching 45.5%,which was 25.7%higher than that of non-peeled seeds.The germination of Ormosia saxatilis was limited by seed coat,and the combination of seed coat removal and temperature change at 25℃/20℃had the best germination effect,with the gemination rate as high as 61.0%.The seed coat extract and embryo extract of Ormosia saxatilis could inhibit the gemination of Brassicca campestris seeds.With the increases of extract solution concentration,the germination inhibition rate gradually increased and the seed germination rate gradually decreased.The inhibitory effect of seed coat extract was significantly higher than that of embryo.Compared with the control,the germination rate of Brassicca campestris seeds treated with 0.01g·mL^(−1),0.05g·mL^(−1) and 0.1g·mL^(−1) seed coat methanol extract decreased by 20.0%,42.0%and 64.0%respectively,and the germination inhibition rate increased by 25.6%,53.9%and 84.6%respectively.It was preliminarily considered that the reasons for seed dormancy of Ormosia saxatilis was poor seed coat permeability,and the inhibitory substances contained in seed coat and embryo.