Sexual and Apomictic Seed Reproduction in Aronia Species with Different Ploidy Levels

Abstract

The genus Aronia Medik., also known as chokeberry, is a group of deciduous shrubs in the Rosaceae family, subtribe Pyrinae. The four commonly accepted species include A. arbutifolia (L.) Pers., red chokeberry; A. melanocarpa (Michx.) Elliott, black chokeberry; A. prunifolia (Marshall) Reheder, purple chokeberry; and A. mitschurinii (A.K. Skvortsov & Maitul). Wild and domesticated Aronia species are found as diploids, triploids, and tetraploids. Genetic improvement of polyploid Aronia genotypes has been limited by suspected apomixis, which may be widespread or distinct to tetraploids. The objectives of this study were to elucidate the reproductive mechanisms of Aronia species and reveal the occurrence of apomixis within the genus and along ploidy lines. Twentynine Aronia accessions [five A. melanocarpa (23), five A. melanocarpa (43), eight A. prunifolia (33), four A. prunifolia (43), six A. arbutifolia (43), and one A. mitschurinii (43)] were used in this study. Intra-accession variability was evaluated by growing out progeny from each open-pollinated maternal accession and comparing plant phenotypes, ploidy levels, and amplified fragment length polymorphism (AFLP) marker profiles between the progeny and maternal accession. Progeny of diploid and tetraploid maternal plants had ploidy levels identical to maternal plants, except for UC009 (A. melanocarpa, 23) which produced a mix of diploids and tetraploids. UC143 and UC149 (A. prunifolia, 33) produced all triploid offspring, whereas all other triploid accessions produced offspring with variable ploidy levels including 23, 33, 43, and 53. Pentaploid Aronia has not been previously reported. Diploid accessions produced significant AFLP genetic variation (0.68-0.78 Jaccard's similarity coefficient) in progeny, which is indicative of sexual reproduction. Seedlings from tetraploid accessions had very little AFLP genetic variation (0.93-0.98 Jaccard's similarity coefficient) in comparison with their maternal accession. The very limited genetic variation suggests the occurrence of limited diplosporous apomixis with one round of meiotic division in tetraploid progeny. Triploid accessions appear to reproduce sexually or apomictically, or both, depending on the individual. These results support our understanding of Aronia reproductive mechanisms and will help guide future breeding efforts of polyploid Aronia species.

Comparing Genotypic and Phenotypic Variation of Selfed and Outcrossed Progeny of Hemp

“…Samples were stored in a -80°C freezer until DNA extraction. Genomic DNA was extracted and AFLP reactions were carried out following the protocol outlined in Mahoney et al (2019). Quality and concentration of extracted DNA were measured using a spectrophotometer (NanoDrop-1000; Thermo Scientific, Willington, DE).…”

Pre- and Postzygotic Barriers Associated with Intergeneric Hybridization between Aronia melanocarpa (Michx.) Elliott x Pyrus communis L. and ×Sorbaronia dippelii (Zabel) CK Schneid. x Pyrus communis

“…AFLP markers have previously been used in Aronia because of their high frequency of polymorphisms and reproducibility (Leonard et al, 2013;Mahoney et al, 2019). In addition, Leonard et al (2013) demonstrated that AFLP markers can be used across Aronia, Pyrus, and other closely related taxa.…”

“…DNA extraction and amplified fragment length polymorphism (AFLP) procedure. Genomic DNA was extracted following the protocol outlined in Mahoney et al (2019). The quality and concentration of extracted DNA were determined using a NanoDrop-1000 spectrophotometer (Thermo Scientific, Willington, DE).…”

De novo assembly of a fruit transcriptome set identifies AmMYB10 as a key regulator of anthocyanin biosynthesis in Aronia melanocarpa

“…Skvortsov & Maitul) (tetraploid) and it is used in commercial fruit production, usually as the cultivars ‘Viking’ or ‘Nero’ [ 3 ]. Diploid A. melanocarpa reproduce sexually and are most commonly found in the Northeastern United States, primarily in the New England region [ 4 , 5 ]. These fruits can easily be identified by the presence of dark-colored fruits in mid- to late summer.…”