Triton X-100 solubilized chloroplast DNA but not nuclear DNA from a mixture of chloroplasts and nuclei. The buoyant density of chloroplast DNA was different from that of the satellite DNA in all of the species examined (Phaseolus coccineus, Cucumis sativus, Cucumis melo, Antirrhinum majus, Vicia faba, Oenothera fruiticosa youngii). Chloroplast DNA constituted between 4.3% and 0.25% of the total...

Herbarium specimens deposited in publicly accessible collections are the basis for all scientific names because only permanent specimens can be re-studied by independent researchers, the very essence of science. Re-investigations may be done with morphological, chemical, genomic, computer-tomographic, or other methods. Based on new herbarium material, I here provide a name for the Xishuangbanna...

DINUROTHRIPS HOOKERI HOOD (THYSANOPTERA: THRIPIDAE: PANCHAETOTHRIPINAE): UN NUEVO RÉCORD PARA CUCUMIS SATIVUS EN PUERTO RICO

This investigation describes the synthesis and biological evaluation of a series of oxabicyclic analogues related to the helminthosporins. Four oxabicycles were prepared by [4+3] cycloaddition of an oxyallyl carbocation, generated in situ from 2,4-dibromopentan-3-one, with selected furans. Functional group manipulations of the oxabicyclic architecture generated nine further derivatives. The phy...

In North Carolina, approximately 8% of the cucumber (Cucumis sativus) yield is lost to root-knot nematodes (Meloidogyne spp.) (Main and Gurtz, 1989). No resistance was found in cucumber after screening of 900 cultigens for resistance to Meloidogyne incognita race 3 (Walters, 1991). African horned cucumber (Cucumis metuliferus) has resistance to M. incognita (Fassuliotis, 1967; Walters, 1991), a...