Interspecific hybridization in cucumis

摘要: A. The genusCucumis and its close relatives in the family Cucurbitaceae have long supported a disorganized tangle of misinformation resulting from incorrect identification plant cultures. Several disease resistance surveys other studies on exotic species cucurbits reported information unverified often misnamed cultures, but during past decade many identity errors inCucumis been corrected by critical inquiry. B. The data cross-fertility tests are compatible with morphology, cytogenetics, phytogeography, physiology (cucurbitacins). They indicate: 1. C. anguria var.longipes is closely related toC. var.anguria may be progenitor. 2. C. leptodermis andC. myriocarpus as varieties or subspecies rather than distinct species. 3. C. zeyheri no closer prophetarum, it species. 4. C. dinteri sagittatus species. 5. C.hardwickii sativus species. C. The indicate thatCucumis can tentatively organized into four cross-sterile groups: 1. Eight spiny-fruited, African ofCucumis var.anguria, yielding partly fertile hybrids it. 2. C. metuliferus not to any used these studies. 3. C. sativus, including cultivated forms seven-chromosomeC. hardwickii India, 12-chromosome Africa their relative,C. var.anguria. 4. The three young fruits hairy lacking operculate spines (C. humifructus, C. melo forms, C.sagittatus includingC. dinteri) more one another they studied. D. Crosses yield developed seeds. Work additional collections those “bridging species” form that will permit transfer genes intoC. melo. Embryo culture techniques useful culturing minute embryos observed crosses. E. The abundance specific structure soft group appear unrelated barriers. Spine differentiation occurs within well between interfertile entities.