The morphological characterization of the dry seeds and reserve mobilization during germination in Morinda citrifolia L.

ABSTRACT Information about the morphology, chemical composition and reserve mobilization is important in understanding the establishment of native and exotic species. The purpose of this study was to describe the morphology, chemical composition, and mobilization of reserves during germination of noni (Morinda citrifolia L.). Biometric and morphological analyzes were performed with 100 randomly selected dried seeds. Other seeds were treated with sulfuric acid PA and soaked in Petri dishes. Collected seeds of five different times of germination were used for cytochemical and chemical analysis. For cytochemical analysis, the cuts of 5μm were submitted to dyes TB at pH 4.0; XP at pH 2.5, reaction of PAS and Sudan IV. The seeds were crushed for chemical analysis with lipids, proteins and soluble sugars extraction that were determined gravimetrically, by the Bradford method and the Antrona method, respectively. The fatty acid composition of the dry seed was determined by gas chromatography. Noni seeds are albuminous and have a thick seed coat, rich in lignin. Lipid and protein bodies were observed inside the endosperm cells, representing 43.50% and 9.15% respectively, while the reservoir of soluble sugars was less than 5%. Linoleic acid was the most prevalent with 68.1%. The lipids were mobilized during germination, suffering a reduction of up to 38% of its total. Proteins, as well as lipids decreased by 25.78% during the germination period observed. The main reserves of noni seeds are lipids and proteins that are mobilized during germination to provide energy and matter to the developing embryo and synthesis of more complex compounds.

摘要
了解植物的形态特征、化学组成与贮藏物质动员机制，对于阐释本土与外来物种的定植过程具有重要意义。本研究旨在阐明诺丽（noni，*Morinda citrifolia* L.）种子萌发过程中的形态特征、化学组成及其贮藏物质动员模式。
研究随机选取100粒干燥种子开展生物计量与形态学分析；其余种子经分析纯硫酸处理后，置于培养皿中进行浸种。选取五个不同萌发时段采集的种子，用于细胞化学与化学组成分析。细胞化学分析环节，将5μm厚的组织切片分别以pH 4.0的TB染料、pH 2.5的XP染料染色，同时进行过碘酸雪夫（PAS）反应与苏丹IV（Sudan IV）染色。化学组成分析时，先将种子粉碎以提取脂质、蛋白质与可溶性糖，其中脂质含量采用重量法测定，蛋白质含量采用布拉德福德（Bradford）法测定，可溶性糖含量则采用蒽酮（Antrona）法测定；采用气相色谱法测定干燥种子的脂肪酸组成。
结果显示，诺丽种子为具胚乳种子，种皮厚实且富含木质素。胚乳细胞内可见脂体与蛋白体，其含量分别占种子干重的43.50%与9.15%，而可溶性糖贮藏量不足5%。亚油酸为最主要的脂肪酸，占总脂肪酸的68.1%。萌发过程中脂质发生动员，总含量最多可减少38%；在本次观测的萌发周期内，蛋白质与脂质的含量均下降了25.78%。诺丽种子的主要贮藏物质为脂质与蛋白质，二者在萌发过程中发生动员，为发育中的胚提供能量与物质基础，并用于合成更为复杂的化合物。