短枝木麻黄种群苗期表型多样性评价

以来源于大洋洲原生种源区、亚洲原生种源区、亚洲引种次生区以及非洲引种次生区4个区域的20个种源短枝木麻黄种子和当年生幼苗为材料,通过种子千粒重以及幼苗苗高、地径、一级侧枝粗度、一级侧枝长度等7个性状对短枝木麻黄表型多样性进行了研究,以探讨种群苗期表型遗传差异,为短枝木麻黄早期遗传选择和遗传改良提供基本资料。结果表明:(1)短枝木麻黄种子千粒重在区域间和区域内种源间差异极显著,且千粒重具有显著的地理变异模式,随经度的增大而降低。(2)当年生幼苗苗高、地径在不同区域间及区域内种源间均存在极显著差异,其中泰国干东港种源幼苗生长最好(苗高76.6cm,地径4.64mm),而种源汤加的幼苗生长最差(苗高28.3cm,地径2.58mm)。(3)当年生幼苗一级侧枝粗度、一级侧枝长度、二级侧枝长度、每小枝节数和齿叶数在不同区域间及区域内种源间均存在极显著差异,其中齿叶数在区域间的变异系数最大(82.15%)。(4)通径分析表明,一级侧枝长度对苗高具有显著的正向影响作用,而一级侧枝粗度和二级侧枝长度对地径具有显著正向影响作用,它们可作为短枝木麻黄优良新品种筛选的参考因子。

Variation Analysis on Morphological Traits of Casuarina equisetifolia at Seedling Stage from Different Regions

Seeds and one-year seedlings of Casuarina equisetifolia from 20 provenances were studied on weight per thousand seeds and seven characters (height,ground diameter,thickness of first order branches,length of first order branches,length of second order branches,nodes per branch,teeth),in order to investigate the morphology diversity of C.equisetifolia and collect the base genetic information for early genetic selection of this specie.The results showed that:(1)highly significant variance of weight per thousand seeds could be both found between the provenances and the regions(P<0.01),and the variation of weight per thousand seeds has shown significant geographic pattern.The weight per thousand seeds would decreased with the increment of longitude;(2)height and ground diameter have extremely significant different between regions and in region(P<0.01),the provenance from Do Donggang Thailand has the best growth condition,for height is 76.6 cm,ground diameter is 4.64 mm;while provenance from Tonga has the worst seedling growth,for height is 28.3 cm,ground diameter is 2.58 mm;(3)highly significant difference of thickness of first order branches,length of first order branches,length of second order branches,nodes per branch and teeth could be found between regions and in region;of which,the coefficient variation between regions of teeth was maximum (82.15%);(4)path analysis results showed that length of first order branches has a significant effect on height,thickness of first order branches and length of second order branches have significant effect on ground diameter.These three traits could be used as reference factor for excellent variety selection of C.equisetifolia.