ESTIMATION OF NUCLEAR RATIOS DIRECTLY FROM HETEROKARYOTIC MYCELIA IN SCHIZOPHYLLUM

摘要: MENZEL, MARGARET Y. (Florida State U., Tallahassee), and F. D. WILSON. Cytotaxonomy of twelve species Hibiscus seetion Furcaria. Amer. Jour. Bot. 50(3): 262-271. Illus. 1963.-Metaphase-I chromosome numbers pairing in 88 accessiens showed that H. cannabinus, costatus, surattensis are diploid (n = 18); acetosella, aculeatus, bifurcatus, furcellatus, meeusei, radiatus, rostella tus sabdariffa tetraploid 36), with similar low multivalent frequencies, hence probably allotetraploids each combining 2 well-differentiated genomes. No intraspecific variation ploidy was found. Fertile, vigorous F1 hybrids between furcellatus bifurcatus complete confirming a close relationship the parents. Two African strains diversifolius were octoploid 72) frequency contain 4 differentiated At least 4, perhaps 5 or 6, genome groups represented tropical Africa, at American tropics. A SHORTAGE j ute world markets, which began during World War II has become more acute as jute-producing regions consume ever larger percentages their own output, led to interest jute substitutes less demanding cultural requirements amenable economical production other parts (cf. Bally, 1955a, b). genus (Malvaceae), cannabinus L. ('kenaf') ('roselle'), among promising substitutes. One chief obstacles cultivation kenaf Florida is its 1 Received for publication August 8, 1962. This report based on research conductet1 cooperatively by Crops Research Division Agricultural Engineering Division, Service, United States Department Agriculture, University Experiment Station, Everglades Belle Glade, Florida. The senior author acknowledges courtesy Biological Sciences, University, making available laboratory space facilities cytological studies. Thanks extended many organizations individuals, some whom not mentioned paper, whose cooperation made it possible assemble living materials information this study based. Geneticists, Agriculture. susceptibility root-knot nematodes (Summers, Pate, Wilson, 1958). Genetic resistance exists acetosella Welw. ex Hiern (Pate, Summers, Menzel, 1958) L., lesser degree radiatus Cav. been successfully crossed cannabinus. cross readily (Menzel 1961b), but triploid practically sterile fertile, colchicine-induced cannabinus-acetosella allohexaploid agronomically unsatisfactory. Hence, survey relatives undertaken additional sources genetic variation. belong section Furcaria DC. genus, characterized leathery succulent fruiting calyx 110 prominent nerves ribs: lobes medial nerve, commissural nerve passes sinus then branches form ridge along margin lobe. epicalyx bracts (bracteoles) numerous, free joined only base, frequently divided tip into an inner outer fork. Section Furcaria, deThis content downloaded from 157.55.39.27 Mon, 05 Sep 2016 03:59:52 UTC All use subject http://about.jstor.org/terms