Spiraea

Abstract: The Chinese Cacopsylla species associated with Spiraea are revised. Three new species (Cacopsylla falcata sp. nov., C. nocturna sp. nov. and C. qilianensis sp. nov.) are described, and two [C. hyalinonemae Li and Yang, 1989 and C. spiraeicola (Li, 2011) comb. nov.] are redescribed. A new combination is also proposed for Cacopsylla tetrotaenialis (Li and Yang, 1989) comb. nov. Among the five species, C. falcata and C. qilianensis are affirmed to develop on Spiraea, as fifth instar immatures were found. The host plants of the other species remain uncertain. Based on morphological grounds, it is suggested that C. falcata and C. nocturna are closely related, but that the five species associated with Spiraea do not constitute a monophyletic group.

Abstract: Tribe Spiraeeae has generally been defined to include Aruncus, Kelseya, Luetkea, Pentactina, Petrophyton, Sibiraea, and Spiraea. Recent phylogenetic analyses have supported inclusion of Holodiscus in this group. Spiraea, with 50-80 species distributed throughout the north temperate regions of the world, is by far the largest and most widespread genus in the tribe; the remaining genera have one to several species each. Phylogenetic analyses of nuclear ITS and chloroplast trnL-trnF nucleotide sequences for 33 species representing seven of the aforementioned genera plus Xerospiraea divided the tribe into two well supported clades, one including Aruncus, Luetkea, Holodiscus, and Xerospiraea, the second including the other genera. Within Spiraea, none of the three sections recognized by Rehder based on inflorescence morphology is supported as monophyletic. Our analyses suggest a western North American origin for the tribe, with several biogeographic events involving vicariance or dispersal between the Old and New Worlds having occurred within this group.

Abstract: Initiation of stem callus cultures on a nutrient medium with either 3% sucrose and (or) 3% sorbitol as carbon source was attempted with 17 species selected from the following genera of the Rosaceae: Amelanchier, two spp.; Crataegus, one sp.; Malus, one sp.; Prunus, nine spp.; Pyrus, one sp.; Sorbus, two spp.; and Spiraea, one sp. In the case of Malus pumila var. niedzwetzkyana (crabapple), sucrose and sorbitol media were equally effective in callus initiation, and equal growth was maintained on these media. Callus of Spiraea vanhouttei was initiated only on sucrose medium and no callus of Prunus tenella formed on either medium. With all other species, callus was initiated and (or) gave better growth on further subculture on sucrose than on sorbitol medium, except for Prunus persica (peach), which grew better on sorbitol.