Substantial Genetic Progress in the International Apis mellifera carnica Population Since the Implementation of Genetic Evaluation

Abstract

The Apis mellifera carnica subspecies of the honeybee has long been praised for its gentleness and good honey yield before systematic breeding efforts began in the early 20th century. However, before the introduction of modern techniques of genetic evaluation (best linear unbiased prediction, BLUP) and a computerized data management in the mid 1990s, genetic progress was slow. Here, the results of the official breeding value estimation in BeeBreed.eu are analyzed to characterize breeding progress and inbreeding. From about the year 2000 onward, the genetic progression accelerated and resulted in a considerable gain in honey yield and desirable properties without increased inbreeding coefficients. The prognostic quality of breeding values is demonstrated by a retrospective analysis. The success of A. m. carnica breeding shows the potential of BLUP-based breeding values and serves as an example for a large-scale breeding program.

Simulation studies to optimize genomic selection in honey bees

“…The second trait had a higher negative genetic correlation (HGC). The chosen genetic parameters roughly represented the estimates for economically important traits such as honey yield or gentleness [7,12,26]. Table 2 summarizes all genetic parameters.…”

“…The genetic variance in worker groups equals the variance of the selection criterion in CBS. Therefore, the heritability of the selection criterion in CBS (called accessible heritability in [7]) is equal to:…”

“…The consequence of the honey bee's reproductive biology is uncertain paternity. To alleviate the resulting practical problems, controlled mating is applied in various honey bee populations [7,12,13], where unfertilized queens are brought to mating stations to mate with drones. Mating stations are located in isolated areas, which in practice are often islands or valleys, where only drones from selected colonies headed by drone-producing queens (DPQ) are available.…”

“…We refer to a group of DPQ on a mating station as a pseudo-father [14]. In practice [7], DPQ are at least one year old when they are deployed on mating stations.…”

A theoretical derivation of response to selection with and without controlled mating in honeybees

“…This is especially important since the sizes of the passive populations relative to the breeding populations as they were used in the simulation studies in [ 14 ] were suitable to illustrate general phenomena but not necessarily realistic. For example, the large Central European breeding population of Apis mellifera carnica managed by beebreed.eu comprises about 8000 breeding queens per year [ 39 ], but the German Beekeepers’ Association (DIB) estimates the total number of honeybee colonies in Germany to be approximately 1,000,000 [ 40 ]. Applying our formulas to specific real cases allows, for example, the expected benefits from the introduction of controlled mating in breeding systems that have previously relied on free-mated queens to be quantified.…”