Nuclear genome size variation in fleshy-fruited Neotropical Myrtaceae

Abstract

In Myrtaceae, reports regarding the nuclear DNA content are scarce. The aim of this study is to present genome size data for fleshy-fruited Myrteae, and to test their relation with chromosome number and ploidy, the available data for cytoevolutionary studies in Myrtaceae. Thirty species out of ten genera were investigated for chromosome number and genome size using flow cytometry. Twenty-eight species were diploid with 2n = 2x = 22 and two species were tetraploid with 2n = 4x = 44. All genome sizes measured are new. Among the diploid species, a gradual and small variation in 2C-values (0.486 pg in Gomidesia schaueriana to 0.636 pg in Eugenia multicostata) was observed, whereas the tetraploid genomes of Psidium acutangulum and P. cattleianum had about twice as much DNA (1.053 and 1.167 pg, respectively). The total interspecific variation of C-values was 2.45-fold. The fleshy-fruited Myrteae have smaller holoploid genomes than the capsular-fruited Eucalypteae and Melaleuceae.

Progress in Myrtaceae genetics and genomics: Eucalyptus as the pivotal genus

“…Recently, however, the average nuclear DNA content of 32 species from ten genera of fleshy-fruited Myrtaceae was reported to be significantly smaller when compared with capsular-fruited Eucalypteae and Melaleuceae. Nuclear DNA content for species of genera Eugenia, Myrciaria, Calyptranthes, Acca, Campomanesia, and Psidium, all regular diploids (2n022), averaged around 0.5/2 C, while two tetraploid species of Psidium presented the expected doubled amount of DNA, around 1.0 pg/2 C (da Costa et al 2008). Based on a wider sampling of genera provided by all these studies, the range of nuclear DNA content (0.25/1 C to 0.8/1 C) of Myrtaceae is significantly below the average for diploid Rosids (2.17/1 C) (Leitch and Bennett 2004) and small to intermediate by the classification of Soltis et al (2003).…”

“…As regular diploid, with a relatively small number of chromosomes and small genome sizes, the main genera of Myrtaceae are strong candidates for genomic undertakings that demand physical manipulation of DNA such as positional cloning. Moreover, the upcoming availability of a reference genome sequence for E. grandis, together with Costa et al (2008) increasingly powerful high-throughput sequencing technologies will provide exceptional opportunities for wholegenome comparative and evolutionary studies across genera in the Myrtaceae.…”

How small and constrained is the genome size of angiosperm woody species

“…The fleshy fruited species of Myrtaceae however, possess smaller genome size than capsular species of Eucalyptae and Melaleuceae. Twenty eight diploid (2n = 2x = 22) species show a variation in 2C values from 0.486 pg in Gomidesia schaueriana to 0.636 pg in Eugenia multicostata while two tetraploids Psidium acutangulum and P. cattleianum show 1.053 pg and 1.167 pg respectively (COSTA et al, 2008). CROS et al (1995) observed a 2-fold variation in 12 diploid (2n = 22) Coffea species belonging to subgenus Coffea with 2C values ranging from 0.95 pg in C. racemosa to 1.78 pg in C. humilis.…”

Myrciaria dubia “Camu Camu” Fruit: Health-Promoting Phytochemicals and Functional Genomic Characteristics

“…[5]. Using flow cytometry, our research group recently determined thatthegenomesizeofcamucamuis$ 230 Mb (unpublished data), which is similar to Myrciaria glazioviana (234 Mb) [6] but is on the lower end of the range (234-1110 Mb) reported for Myrtaceae species [5].…”

“…Myrciaria dubia Kunth (McVaugh) "camu camu" is a typical native Amazonian fruit shrub that thrives in areas exposed to periodical flooding on the banks of rivers, streams, lakes, and swamps of several Amazonian countries [1,2]. This plant species possesses a diploid genome, and their genome size (230 Mb) is in the range of other Myrtaceae species [3][4][5][6]. Populations exhibit moderate genetic diversity and genetic structuring [7][8][9][10][11].…”