不同种源掌叶木种实性状及发芽能力差异

Differences of fruit-seed traits and germination capacity of Handeliodendron bodinieri from different provenances

  • 摘要: 【目的】 为了解不同种源地掌叶木种实性状及发芽能力的差异,挖掘掌叶木野生优质种质资源,为掌叶木优良种源选择提供科学依据。【方法】 以广西田林、乐业、凤山、环江及贵州独山5个种源地掌叶木果实/种子为试材,测量形态大小、含水量、千粒重和发芽率等17项种实性状及种子发芽指标,采用相关分析和聚类分析揭示种实性状、发芽能力与种源地理、气候因子的关系并进行综合评价。【结果】 5个种源间各种实性状及发芽能力差异极显著(P<0.01,下同),其中乐业种源种形系数最大(1.44),凤山的种子含水量最高(43.90%)。17项测定性状变异系数范围为5.02%~103.72%,其中发芽势变异系数最大,平均发芽速度变异系数最小。相关分析结果显示,发芽率与种形系数、种子含水量呈显著正相关(P<0.05,下同),发芽指数与种子含水量呈极显著正相关,表明种形系数越大,种子越狭长、种子含水量越高,发芽能力越强;种实性状和发芽能力与经纬度均无显著相关性(P>0.05),与海拔和年均降水量分别呈正、负相关。主成分分析结果表明,前4个主成分累计方差贡献率达87.110%。聚类分析得出,种子长度和直径较长、发芽率较低的田林、环江、乐业和独山归为一个类群,种子长度和直径较短、发芽率较高的凤山单独为一类群。供试种源中,乐业种源综合得分最高,田林次之。【结论】 掌叶木种实的表型性状和发芽能力种源差异明显,各性状间具有一定相关性。种实性状与发芽能力受海拔、年降水的协同选择作用,具有随机变异的特点,综合评价表明,乐业种源在种实性状和发芽能力表现最优,可作为潜在的优良种源进行培育。

     

    Abstract: 【Objective】 To understand the differences of fruit-seed traits and germination capacity of Handeliodendron bodinieri from different provenances, to excavate wild high-quality germplasm resources of H. bodinieri, and to provide reference for carrying out selection of superior provenances. 【Method】 The fruits/seeds of H. bodinieri from five provenances in Tianlin, Leye, Fengshan and Huanjiang in Guangxi and Dushan in Guizhou were used as test materials. Seventeen traits and seed germination indicators were measured, including morphological size, moisture content, 1000-grain weight and germination percentage. The relationship between fruit-seed traits,germination capacity of H. bodinieri and provenances, geographical and climatic factors were revealed by correlation and cluster analysis, and a comprehensive evaluation was conducted. 【Result】 The differences of fruit-seed traits and germination capacity among the five provenances were extremely significant(P<0.01, the same below), with the largest coefficient of seed shape(1.44) for the Leye provenance and the highest moisture content(43.90%) for Fengshan provenance. The coefficients of variation of the 17 measured traits ranged from 5.02% to 103.72%, with the largest coefficient of variation in germination vigor and the smallest coefficient of variation in the average germination speed. The results of correlation analysis showed that germination percentage was significantly positively correlated with coefficient of seed shape and moisture content in seed(P<0.05, the same below), and germination index had extremely significantly positive correlation with moisture content in seed, indicating that the larger coefficient of seed shape, the narrower and longer the seeds, and the higher the moisture content in seed, the better the germination capacity. Fruit-seed traits and germination capacity had no significant correlation with latitude and longitude(P>0.05), but were positively and negatively correlated with altitude and annual mean precipitation, respectively. The results of principal component analysis showed that top four principal components reached cumulative variance contribution rate of 87.110%. The results of cluster analysis showed that Tianlin, Huanjiang, Leye and Dushan provenances with longer length and diameter of seed but lower germination percentage were classified into one group, while Fengshan provenance with shorter length and diameter of seed but higher germination percentage was a separate group. Among the tested provenances, Leye provenance had the highest comprehensive score, followed by Tianlin provenance. 【Conclusion】 The phenotypic fruit-seed traits and germination capacity of H. bodinieri differ greatly from each other, and there are some correlations among the traits. The fruit-seed traits and germination characteristics of H.bodinieri are synergistically selected by altitude and annual mean precipitation, with random variation characteristics. The comprehensive evaluation shows that the Leye provenance has the best performance in fruit-seed traits and germination capacity, and can be bred by a potential fine provenance.

     

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