Phylogeographic diversity and population structure of Carica papaya L. revealed through nuclear microsatellites

Abstract

It is crucial to analyze the population structure and genetic diversity of the samples to be studied before a breeding program can be launched. Thirty-one genotypes of papaya germplasm from Spain, Brazil, Ecuador, China, Taiwan, India, and several locations in Bangladesh were genotyped using ten polymorphic simple sequence repeat markers to investigate their molecular diversity as well as their genetic relatedness. The highest numbers of alleles, gene diversity and polymorphic information content were seen in the P3K1024CC and P6K900CC markers. This result confirms the suitability of these markers in the assay of the genetic diversity of papaya genotypes. The model-based population structure and the distance-based assessment categorized the genotypes into six different subcategories. The analysis of molecular variance revealed that 11% of the entire genetic diversity was due to differences among the populations, while 89% was a result of differences within the population. The F ST value of 0.136 showed a high level of genetic diversity among the groups alongside a negative F IS (− 0.232) and F IT (− 0.065). The diverse material revealed by our research expands the current papaya genetic resources, which can be used effectively in genomic studies in papaya improvement programs as well as in germplasm conservation studies.

Spatial Scale Patterns of Genetic Diversity and Gene Flow in Populations of Sweet Detar (Detarium microcarpum Guill. & Perr.; Fabaceae)

“…Results of AMOVA indicated that 17.35% of the total genetic diversity was due to differences within populations, while 45.80% of the overall genetic diversity was a result of differences among the population. These relatively low values of variation may be justi ed by the reproductive system of the species (Luo et al 2007;Hasibuzzaman et al 2020) dispersion of the species among farmers (Ov et al 2011), and evolutionary changes within the species. Haplotype diversity re ects the degree of difference among the haplotypes in each population.…”

SSR‐based DNA fingerprinting of fruit crops

“…Papaya is diploid (2 n = 18) (Chávez‐Pesqueira & Núñez‐Farfán, 2017; Hasibuzzaman et al., 2020) with three flower sex types, that is, males, females, and hermaphrodites, controlled by a single locus with at least three alleles: M1, a dominant allele for male plants; M2, a different dominant allele for hermaphrodite plants; and m, a recessive allele for female plants. All combinations of dominant alleles, that is, MM, MMh, and Mh Mh (where M represents the male and Mh represents the hermaphrodite alleles) are lethal to the zygote (Lee et al., 2018).…”