广西多穗柯叶片性状变异及幼苗生长量研究

Variation of leaf traits and seedling growth of Lithocarpus polystachyus in Guangxi

关键词:  多穗柯  产地  叶片性状  变异  幼苗生长量  相关性  优良种质  早期筛选

Key words:  Lithocarpus polystachyus  origin  leaf traits  variation  seedling growth  correlation  superior germplasm  early selecting

摘要:

多穗柯是一种珍贵天然野生药用植物,可以开发出保健食品色素和天然医用药品,广西的资源较丰富,该研究采集巴马、那坡、德保及田林等4个产地的多穗柯种子进行播种育苗,并跟踪调查测定一年生幼苗的叶片性状及幼苗生长量,并进行相关性分析。结果表明:(1)不同产地间叶片性状及幼苗生长指标均存在不同程度的差异,其中巴马与那坡、德保、田林在叶长、叶宽、叶面积、叶脉间距、叶鲜重、叶片干物质含量、叶片组织密度等叶片性状上的差异均达到显著水平,在株高、地径、单株干重、主根长、单株根干重及单株叶干重等生长指标上亦存在显著差异,且生长量是后3个产地的1～2倍; 通过比较各产地的叶片保水力及植株净生长量,巴马的多穗柯植株耐旱性及生长速度优于其他三地。综合各性状表现,认为巴马的多穗柯苗期表现比较好,生长速度快,长势好,抗旱性较强,可作为多穗柯优良种源的初步选择。(2)8月份是多穗柯株高、地径的生长高峰期,建议此时应加强肥水管理,调节适宜的水肥光热条件,尽量延长幼苗的快速生长时间,以获得苗木的最大累积生长量。(3)叶片性状与幼苗生长量的相关性分析结果显示,叶面积与株高、地径、单株干重、单株根干重以及单株叶干重等呈极显著正相关,叶脉间距、叶绿素相对含量(SPAD)与株高、单株干重呈显著或极显著正相关,比叶面积与株高、地径呈显著负相关。因此,在以后的优株表型选择中,要优先考虑叶子大、叶脉间距宽、中老熟叶片叶色浓绿的植株。该研究结果为多穗柯优良种质资源的早期筛选提供了一定的依据。

Abstract:

Lithocarpus polystachyus is a kind of precious natural wild medicinal plants, and can develop health food pigment and natural medicinal drugs. There are rich plant resources in Guangxi. To provide certain reference for early selecting the superior germplasm, seeds from such four origins as Bama, Napo, Debao and Tianlin County were collected and sowed through ascertain difference of leaf morphology index and growth index in seedling plants between different origins of L. polystachyus in Guangxi, for nursing seedlings respectively,and tracking to survey and determine the leaf traits and growth of seedlings aged one,and then compared the degree of variation of leaf area, leaf length, leaf width, leaf thickness, vein spacing, leaf fresh weight, leaf dry matter content, specific leaf area, leaf tissue density, the relative contents of chlorophyll, leaf water retention, plant height, ground diameter, dry weight per plant, taproot length,root dry weight per plant,leaf dry weight per plant between different origins of plants, and further to analyze the correlation between leaf traits and growth of seedling. The results were as follows:(1)There were a lot of differences in leaf traits and seedling growth among different origins, in which the length, width, LAI(leaf-area-index), veins distance, fresh weight, dry weight, tissue density of leaves and mean height, diameter, whole dry weight, root length, root dry weight of individual seedling from Bama were significantly higher than those from Napo, Debao and Tianlin. Mean biomass of individual seedling from Bama was one to two times as much as those from other three origins. Analysis from leaf water holding ability and net growth rate showed that the drought tolerance of seedlings from Bama were higher than those from three other origins. In conclusion, Bama could be considered as a superior provenance on a preliminary basis;(2)The growth peak of L. polystachyus was in August in Guangxi, the plant height and the ground diameter growed significantly at this time. In order to obtain the largest accumulation of seedling growth,some proposal that strengthen the water management, adjust the suitable conditions of field water, and as far as possible to prolong rapid growth of seedlings should be put forward;(3)Correlation analysis indicated that LAI had extremely positive correlation with seedling height, diameter, individual whole dry weight, root length, individual root dry weight and individual leaf dry weight, The veins distance and SPAD value both had positive correlation with seedling height and individual seedling whole dry weight, while SLA(specific leaf area)had negative correlation with seedling height and diameter. Therefore, during the phenotype selection in the future, priorities should go to the seedlings with mature thick-green leaves of broad leaf area and veins distance.