Mango (Mangifera indica) is an economically and nutritionally important tropical/subtropical tree fruit crop. Most of the current commercial cultivars are selections rather than the products of breeding programs. To improve the efficiency of mango breeding, molecular markers have been used to create a consensus genetic map that identifies all 20 linkage groups in seven mapping populations. Polyembryony is an important mango trait, used for clonal propagation of cultivars and rootstocks. In polyembryonic mango cultivars, in addition to a zygotic embryo, several apomictic embryos develop from maternal tissue surrounding the fertilized egg cell. This trait has been associated with linkage group 8 in our consensus genetic map and has been validated in two of the seven mapping populations. In addition, we have observed a significant association between trait and single nucleotide polymorphism (SNP) markers for the vegetative trait of branch habit and the fruit traits of bloom, ground skin color, blush intensity, beak shape, and pulp color.

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Avocado (Persea americana) is an important tropical and subtropical fruit tree crop. Traditional tree breeding programs face the challenges of long generation times and significant expense in land and personnel resources. Avocado selection and breeding can be more efficient and less expensive through the development and application of molecular markers. A total of 1524 individuals were genotyped with 384 SNPs creating the largest SNP genotype database for avocado. These individuals correspond to four extensive germplasm collections including two housed in Florida and two in California. In addition, hybrids and selections from two rootstock breeding programs have been genotyped. Genotype data were analyzed using an affinity propagation method to define 155 groups. The 384 SNP markers provided accurate genotype data for individuals from different Persea species as well as half-siblings. Therefore, the majority of the genetic diversity of the avocado germplasm and related species that were genotyped has been captured. A simple visual method can also be used to identify self-pollinated individuals among the half-siblings of known maternal parents and, in some cases, to infer likely candidates for the paternal parent. Finally, this dataset is unambiguous so breeders can determine the genetic diversity of their breeding stock to optimize avocado breeding and selection programs by identifying outcrossed individuals at the seedling stage, thus increasing the efficiency of avocado genetic improvement.

The naked mole rat, Heterocephalus glaber, is a highly unusual mammal that displays a complex social system similar to that found in eusocial insects. Colonies of H. glaber are commonly maintained in zoo collections because they represent fascinating educational exhibits for the public. However, little is known about the genetic structure or sex ratio of captive populations of H. glaber. In this study, we developed a set of microsatellite markers to examine genetic variation in three captive zoo populations of H. glaber. We also studied sex ratio of these captive populations. Our goal was to determine levels of genetic variation within, and genetic differences between, captive populations of H. glaber. Overall, we found modest levels of genetic variation in zoo populations. We also uncovered little evidence for inbreeding within the captive populations. However, zoo populations did differ genetically, which may reflect the isolation of captive naked mole rat colonies. Finally, we found no evidence of biased sex ratios within colonies. Overall, our study documents levels of genetic variation and sex ratios in a captive eusocial mammalian population. Our results may provide insight into how to manage captive populations of H. glaber.