Timing of rapid diversification and convergent origins of active pollination within Agavoideae (Asparagaceae).

PREMISE OF THE STUDY: Yucca species are ideal candidates for the study of coevolution due to the obligate mutualism they form with yucca moth pollinators (genera Tegeticula and Parategeticula). Yuccas are not the only species to exhibit a mutualism with yucca moths; the genus Hesperoyucca is pollinated by the California yucca moth (Tegeticula maculata). Relationships among yuccas, Hesperoyucca, and other members of subfamily Agavoideae are necessary to understand the evolution of this unique pollination syndrome. Here, we investigate evolutionary relationships of yuccas and closely related genera looking at the timing and origin of yucca moth pollination. METHODS: In this study, we sequenced the chloroplast genomes of 20 species in the subfamily Agavoideae (Asparagaceae) and three confamilial outgroup taxa to resolve intergeneric phylogenetic relationships of Agavoideae. We estimated divergence times using protein-coding genes from 67 chloroplast genomes sampled across monocots to determine the timing of the yucca moth pollination origin. KEY RESULTS: We confidently resolved intergeneric relationships in Agavoideae, demonstrating the origin of the yucca-yucca moth mutualism on two distinct lineages that diverged 27 million years ago. Comparisons of Yucca and Hesperoyucca divergence time to those of yucca moths (Tegeticula and Parategeticula, Prodoxidae) indicate overlapping ages for the origin of pollinating behavior in the moths and pollination by yucca moths in the two plant lineages. CONCLUSION: Whereas pollinating yucca moths have been shown to have a single origin within the Prodoxidae, there were independent acquisitions of active pollination on lineages leading to Yucca and Hesperoyucca within the Agavoideae.

Revision of the Japanese species of Epicephala Meyrick with descriptions of seven new species (Lepidoptera, Gracillariidae).

Epicephala moths are involved in obligate mutualisms with their Phyllanthaceae hosts, in which the female moths assure pollination and, in return, their progeny develop by consuming the seeds. Ecological, molecular and geographical data suggest that the genus includes several hundred species, but the majority remains to be formally described. Here we revise the Japanese species of Epicephala Meyrick, 1880. In addition to two previously named species, seven species are newly described: Epicephala anthophilia sp. n., Epicephala lanceolatella sp. n., Epicephala perplexa sp. n., Epicephala obovatella sp. n., Epicephala corruptrix sp. n., Epicephala parasitica sp. n. and Epicephala nudilingua sp. n. The first four are species involved in obligate pollination mutualism, while the fifth is a pollinating seed parasite and the last two are derived non-pollinating seed parasites of herbaceous Phyllanthus. Each of the nine Japanese Epicephela species is specialized to a single plant species in the genera Glochidion, Breynia or Phyllanthus, except for Epicephala obovatella and Epicephala corruptrix that each utilizes two closely related Glochidion species. Considerable variations are found in pollination and oviposition behaviors among species, which are reflected in their proboscis and ovipositor morphologies, respectively. Molecular phylogeny indicated that there have been repeated transitions in oviposition mode during the diversification of Epicephala, which were accompanied by changes in ovipositor morphology, as suggested by a correlation analysis. Keys to species are provided.

Extremely high proportions of male flowers and geographic variation in floral ratios within male figs of Ficus tikoua despite pollinators displaying active pollen collection.

Most plants are pollinated passively, but active pollination has evolved among insects that depend on ovule fertilization for larval development. Anther-to-ovule ratios (A/O ratios, a coarse indicator of pollen-to-ovule ratios) are strong indicators of pollination mode in fig trees and are consistent within most species. However, unusually high values and high variation of A/O ratios (0.096-10.0) were detected among male plants from 41 natural populations of Ficus tikoua in China. Higher proportions of male (staminate) flowers were associated with a change in their distribution within the figs, from circum-ostiolar to scattered. Plants bearing figs with ostiolar or scattered male flowers were geographically separated, with scattered male flowers found mainly on the Yungui Plateau in the southwest of our sample area. The A/O ratios of most F. tikoua figs were indicative of passive pollination, but its Ceratosolen fig wasp pollinator actively loads pollen into its pollen pockets. Additional pollen was also carried on their body surface and pollinators emerging from scattered-flower figs had more surface pollen. Large amounts of pollen grains on the insects' body surface are usually indicative of a passive pollinator. This is the first recorded case of an actively pollinated Ficus species producing large amounts of pollen. Overall high A/O ratios, particularly in some populations, in combination with actively pollinating pollinators, may reflect a response by the plant to insufficient quantities of pollen transported in the wasps' pollen pockets, together with geographic variation in this pollen limitation. This suggests an unstable scenario that could lead to eventual loss of wasp active pollination behavior.

Isolation and characterization of 11 microsatellite markers for Glochidion acuminatum (Phyllanthaceae).

PREMISE OF THE STUDY: Microsatellite markers were developed for Glochidion acuminatum (Phyllanthaceae) to investigate pollen dispersal distances and thereby to assess the effectiveness of specialized Epicephala moths as pollinators. • METHODS AND RESULTS: Using next-generation sequencing, 11 polymorphic microsatellite primer pairs were developed for G. acuminatum. The primer pairs were tested on 49 individuals from two populations in Japan. The number of alleles per locus ranged from two to 13, and the expected heterozygosity ranged from 0.12 to 0.85. Probability of identity for all loci combined was lower than 1.27 × 10(7). • CONCLUSIONS: The microsatellite markers developed in this study will be useful for evaluating the benefit of specialized Epicephala moth pollination to Glochidion plants.