Dyschoriste Nees.

Daniel, Thomas F., 2018, Chromosome Numbers of Some Cultivated Acanthaceae with Notes on Chromosomal Evolution in the Family, Proceedings of the California Academy of Sciences 64 (9), pp. 319-332 : 323

Dyschoriste Nees.

— Dyschoriste (including Apassalus Kobuski , Chaetacanthus Nees , and Sautiera Decne. ) is a genus of 80 or more species that occur in tropical and warm-temperate regions of the Americas, Africa, Madagascar, and Asia. Our count of n = 15 for D. thunbergiiflora (S. Moore) Lindau ( Fig. 1A ) is the first count for this species of eastern Africa, and the first count for an African representative of genus ( D. nagchana (Nees) Bennet occurs in both Africa and Asia, but only plants from the latter region have apparently been studied cytologically). Our count for an African species demonstrates the occurrence of a common number (n = 15) throughout the distributional range of the genus: North America (6 species with this number; Daniel 2000a; Daniel et al. 1990), South America (1 species; Piovano and Bernardello 1991), and Asia (1 species; Govindarajan and Subramanian 1985). This same number occurs in three of the “geographically cohesive” and weakly to strongly supported New World clades of the genus as revealed by the molecular phylogenetic studies of Chumchim et al. (2015). Counts of both n = 15 (Govindarajan and Subramanian 1985) and n = 30 (e.g., Saggoo and Bir 1982) have been reported for Dyschoriste nagchana (as D. depressa Nees ) in Asia, and the only count for D. hirsutissima (Nees) Kuntze from Mexico is n = 30 ( Daniel et al. 1990). Thus, polyploidy within a species and also possibly at the specific level is evident in the genus. A basic number of x = 15 appears likely for Dyschoriste , as noted by Daniel (2000a). The only other counts reported for the genus are n = 14 for D. madurensis (Burm.f.) Kuntze ( Narayanan 1951; as D. littoralis (L.f.) Nees) and n = 28 for D. vagans (Wight) Kuntze ( Kaur 1969), both Asian species. If those latter counts and are accurate, then another possible basic number in the genus is x = 14, and dysploidy is potentially also involved in the evolution of some species.

Based on counts to date, apparent dysploidy and polyploidy would appear to be evident among genera related to Dyschoriste . The genus pertains to Ruellieae: Petalidiinae ( Tripp et al. 2013) where its relatives consist of five other genera related as follows: ( Ruelliopsis + Phaulopsis ) + (( Petalidium + Duosperma ) + ( Dyschoriste + Strobilanthopsis )). Chromosome numbers have been reported for two other genera of the subtribe. A count of n = 16 has been reported several times for Petalidium barlerioides Nees (summarized in Tripp et al. 2013), and counts for 11 species of Phaulopsis reveal n = 16 (or ca. 16) in nine of them ( Manktelow 1996). Daniel and Chuang (1998) suggested a basic number of x = 16 for the latter genus, in which polyploidy (i.e., n = ca. 32) has been reported for three species ( Manktelow 1996), and possible dysploidy (i.e., n = 17) has been reported for two species that have otherwise been counted as n = 16 ( Daniel & Chuang 1998).

Figures

FIGURE 1 (upper right). Chromosomes of Acanthaceae in pollen mother cells. A. Dyscho- riste thunbergiiflora, metaphase II (only half of cell shown), n = 15. B. Brillantaisia owariensis, telophase I, n = 16 (with one lagging chromo- some toward “upper” pole). C. Brillantaisia owariensis, metaphase I, n = 16. D. Ruellia ele- gans, diakenesis (showing nucleolus, n), n = 17. E. Crossandra infundibuliformis, metaphase I, n = 19. F. Ruellia dipteracanthus, metaphase I, n = 17. G. Justicia scheidweileri, metaphase I, n = 14. Chromosomes shown in outline only are touching or overlapping other chromosomes. Scale applies to all figures. See Table 1 for voucher information.