Study of quantitative genetics of gum arabic production complicated by variability in ploidy level of Acacia senegal (L.) Willd
Study of quantitative genetics of gum arabic production complicated by variability in ploidy level of Acacia senegal (L.) Willd
复制标题
塞内加尔金合欢 (Acacia senegal (L.) Willd) 倍性水平变异导致阿拉伯树胶生产的数量遗传学研究
作者：
A. M. Diallo;L. Nielsen;J. K. Hansen;A. Ræbild;E. D. Kjær
阿拉伯树胶是一种重要的国际商品，由横跨萨赫勒非洲的塞内加尔相思树种生产，但有记录的育种活动结果有限。本研究的目的是提供可靠的数量遗传参数估计，以揭示胶树产量和品质改良的育种潜力。为此，我们测量了60株自由授粉树18年后的617个后代的生长，以及基于建立后18年和19年两个季节的胶产量和品质。用8个微卫星标记进行基因分型，结果表明，后代由二倍体和多倍体树组成，生长、产胶量和胶质在倍性水平、群体和后代之间存在较大差异。分子方差分析和异交率估计支持二倍体自由授粉家系内树木为半同胞，而多倍体自由授粉家系内变异较小。在倍性水平之间观察到的兄弟姐妹关系的差异使遗传参数的估计变得复杂。然而，基于二倍体树，我们得出结论，阿拉伯树胶产量的遗传力是从低到高的，存在较高水平的加性遗传变异，尽管遗传参数只能用相当高的标准误差来估计。这一发现表明，通过育种进行改良可以显著提高塞内加尔的生产力。然而，结果也强调了检测所选材料的倍性水平和使用遗传标记来验证定量遗传分析中的假设的重要性。
Gum arabic is an important international commodity produced by trees of Acacia senegal across Sahelian Africa, but documented results of breeding activities are limited. The objective of this study was to provide reliable estimates of quantitative genetic parameters in order to shed light on the breeding potential for improvement of gum yield and quality. For this purpose, we measured growth on 617 offspring from 60 open-pollinated trees after 18 years, and gum yield and quality based on two seasons, 18 and 19 years after establishment. Genotyping with eight microsatellite markers revealed that progenies consisted of both diploid and polyploid trees, and growth, gum yield, and gum quality varied substantially among ploidy level, populations, and progenies. Analysis of molecular variance and estimates of outcrossing rate supported that trees within open-pollinated families of diploids were half sibs, while the open-pollinated families of polyploids showed low variation within families. The difference in sibling relationship observed between ploidy levels complicated estimation of genetic parameters. However, based on the diploid trees, we conclude that heritability in gum arabic production is low to high with presence of high levels of additive genetic variation, although the genetic parameters could only be estimated with fairly high standard error. The findings suggest that improvement through breeding can increase the productivity of A. senegal substantially. However, the results also stress the importance of testing ploidy levels of selected material and use of genetic markers to qualify the assumptions in the quantitative genetic analysis.
影响因子：
3.3
作者：
D. Houle
通讯作者：
D. Houle