Abstract:
The selection of honeybee strains resistant to the ectoparasitic mite Varroa destructor is generally considered as one of the most sustainable ways of coping with this major bee parasite. Thus, breeding efforts increasingly focus on resistance parameters in addition to common beekeeping traits like honey yield and gentleness. In every breeding effort, the success strongly depends on the quantifiability and heritability of the traits accounted. To find the most suitable traits among the manifold variants to assess Varroa resistance, it is necessary to evaluate how easily a trait can be measured (i.e., testing effort) in relation to the underlying heritability (i.e., expected transfer to the following generation). Various possible selection traits are described as beneficial for colony survival in the presence of Varroa destructor and therefore are measured in breeding stocks around the globe. Two of them in particular, suppressed mite reproduction (SMR, sensu lato any reproductive failure of mother mites) and recapping of already sealed brood cells have recently gained increasing attention among the breeders because they closely resemble resistance mechanisms of some Varroa-surviving honeybee populations. However, it was still unknown whether the genetic background of the trait is sufficient for targeted selection. We therefore investigated the heritabilities and genetic correlations for SMR and REC, distinguishing between recapping of infested cells (RECinf) and all cells (RECall), on an extensive dataset of Buckfast and Carniolan stock in Germany. With an accessible h² of 0.18 and 0.44 for SMR and an accessible h² of 0.44 and 0.40 for RECinf, both traits turned out to be very promising for further selection in the Buckfast and Carnica breeding population, respectively.
摘要:
通常认为,选择抗寄生虫螨的蜜蜂菌株是应对这种主要蜜蜂寄生虫的最可持续方法之一。因此,育种工作越来越注重抗性参数,除了常见的养蜂性状,如蜂蜜产量和温和。在每一次繁殖努力中,成功在很大程度上取决于所占性状的可量化性和遗传力。为了在多种变体中找到最合适的性状来评估瓦螨抗性,有必要评估一个性状的测量有多容易(即,测试努力)与潜在遗传力(即,预期转移到下一代)。各种可能的选择性状被描述为在狄斯瓦螨存在下有利于菌落存活,因此可以在全球的繁殖种群中进行测量。特别是其中两个,抑制螨繁殖(SMR,sensulato母螨虫的任何繁殖失败)和已经密封的育卵细胞的回收最近在育种者中引起了越来越多的关注,因为它们非常类似于某些Varroa存活的蜜蜂种群的抗性机制。然而,目前尚不清楚该性状的遗传背景是否足以进行针对性选择。因此,我们调查了SMR和REC的遗传力和遗传相关性,区分感染细胞(RECinf)和所有细胞(RECall),在德国Buckfast和Carniolan股票的广泛数据集上。SMR的可访问h²为0.18和0.44,RECinf的可访问h²为0.44和0.40,事实证明,这两个性状对于Buckfast和Carnica育种种群的进一步选择非常有希望,分别。