Tatsuya Uemachi

CMV resistance developed in vigorous-growing lateral shoots from virus infected plants of Capsicum annuum L.

Abstract Vigorous-growing lateral shoots were observed emerging from certain pepper cultivars infected with cucumber mosaic virus (CMV) about 2 years after infection. They exhibited no CMV symptoms. When checked by enzyme-linked immunosorbent assay (ELISA), CMV was not detected in the vigorous-growing lateral shoots which emerged from Capsicum annuum L. ‘Af-5’ plants infected with CMV, in spite of a high concentration of CMV in the infected shoots. Vigorous-growing cuttings from ‘Af-5’ plants did not express CMV symptoms, regardless of either the renewal frequency by cutting propagation or the duration of growing. In these cuttings, CMV was never detected when checked by either ELISA or the grafting method. Vigorous-growing cuttings inoculated with CMV by aphids showed no symptoms of CMV, with a CMV concentration index of 0. When tested by the grafting inoculation method, ‘Af-5’ vigorous-growing cuttings were resistant to CMV.

Multilocus coalescent species delimitation to evaluate traditionally defined morphotypes in Hydrangea sect. Asperae (Hydrangeaceae)

The number of species recognized in section Asperae of the flowering plant genus Hydrangea differs widely between subsequent revisions. This variation is largely centered around the H. aspera species complex, with numbers of recognized species varying from one to nearly a dozen. Despite indications of molecular variation in this complex, no sequence-based species delimitation methods have been employed to evaluate the primarily morphology-based species boundaries. In the present study, a multi-locus coalescent-based approach to species delimitation is employed in order to identify separate evolutionary lines within H. sect. Asperae, using four chloroplast and four nuclear molecular markers. Eight lineages were recovered within the focal group, of which five correspond with named morphotypes. The other three lineages illustrate types of conflict between molecular species delimitation and traditional morphology-based taxonomy. One molecular lineage comprises two named morphotypes, which possibly diverged recently enough to not have developed sufficient molecular divergence. A second conflict is found in H. strigosa. This morphotype is recovered as a separate lineage when occurring in geographic isolation, but when occurring in sympatry with two other morphotypes (H. aspera and H. robusta), the coalescent species delimitation lumps these taxa into a single putative species.