Genetic diversity analysis of Artocarpus heterophyllus Lam. × Artocarpus integer (Thunb.) Merr. hybrids using vegetative characters and microsatellite markers

Abstract

Artocarpus is a plant genus widely distributed from Southeast Asia to Oceania. Notably, 34 of 45 Artocarpus species are in Indonesia, especially on Kalimantan Island. Therefore, Kalimantan Island is reconstructed as the center of the diversity of Artocarpus. Some Artocarpus species, including jackfruit (A. heterophyllus Lam.) and cempedak (A. integer [Thunb.] Merr.), are widely cultivated in the community. These plants have monoecious flowers, which makes cross-pollination between species possible. Nangkadak, the progeny of a cross between mini-jackfruit and local cempedak, was developed at the Mekarsari Fruit Garden. This study analyzed the genetic diversity of the progeny of A. heterophyllus × A. integer crosses using vegetative characters and microsatellite markers. Microsatellite markers were used to analyze the phylogeny of six accessions of nangkadak and their parents. DNA was extracted from mature leaves, and PCR amplification was performed using Artocarpus microsatellite primers. Eight primers—MAA178, MAA54a, MAA140, MAA156, MAA145, MAA182, MAA54b, and MAA122—amplified 47 alleles, with an average of 5.8 alleles per locus. The amplification results showed that the microsatellite markers were polymorphic, which indicates kinship between accessions, as observed in the dendrogram of alleles identified from the electropherogram. The analysis of microsatellite markers also suggests that the cross between mini-jackfruit and local cempedak produces an allotetraploid progeny, as indicated by the maximum number of successful alleles amplified at the MAA178 and MAA156 loci. The phylogenetic analysis showed that nangkadak is more closely related to mini-jackfruit, used as the female parent than cempedak.