The Identification of a Suitable Irradication Dosage for Mutation Induction in Zamioculcas Zamiifolia (LODD.) and the Polyploidization of Z. Zamiifolia and Marsdenia Floribunda

Radiation mutation has been successfully used to create a great variety of ornamental crop cultivars by supplementing existing germplasm and improving existing cultivars, and chemical mutagens such as colchicine and oryzalin have been used to create new plant cultivars by doubling the chromosome number of the treated plant material to produce tetraploids. The main objective of this thesis research was to develop protocols to create tetraploid plants of Zamioculcas zamiifolia (Lodd.) Engl., an important foliage plant, and Marsdenia jloribunda (Brongn.), an important lei flower plant, and to determine the LD50 of ZZ leaflets. ZZ leaflets and M floribunda seeds were treated with colchicine at various concentrations and durations in order to induce ploidy changes and regenerate polyploids. Five ZZ tetraploids and one M. floribunda tetraploid were produced using colchicine. A tissue culture protocol was also developed for the oryzalin treatment of ZZ callus for the in vitro polyploidy induction of ZZ. The LD50 of ZZ leaflets irradiated with x-rays was calculated as 20±1 Gy. A ZZ germplasm collection was also initiated to provide ZZ plant material for use in future breeding studies

Spatial correlations of mapped malaria rates with environmental factors in Belize, Central America

BACKGROUND: The purposes of this study were to map overall malaria incidence rates from 1989 through 1999 for villages in Belize; to assess the seasonal distribution of malaria incidence by region; and to correlate malaria incidence rates with vegetation cover and rivers in villages, using geographic information system technology. Malaria information on 156 villages was obtained from an electronic database maintained by the Belize National Malaria Control Program. Average annual malaria incidence rates per 1000 population over 10 years were calculated for villages using the 1991 population census as a denominator. Malaria incidence rates were integrated with vegetation cover from a 1995 vegetation map, and with river data from a digital data set. RESULTS: Mapping malaria incidence over the 10-year period in the study villages indicated the existence of a spatial pattern: the southern and western areas of Belize had consistently higher rates of malaria than northern areas. Examination of the seasonal distribution of malaria incidence by month over 10 years indicated that a statistically significant difference existed among districts and among months (p < 0.05). Spatial analysis of malaria incidence rates and of vegetation in Belize showed villages with high malaria rates having more broadleaf hill forests, agricultural land, and wetland vegetation types (i.e. SWF-seasonally waterlogged fire-induced shrubland of the plains). Statistical and spatial analyses of malaria incidence and of river distributions in Belize determined the high 10 percentile malaria incidence villages in western and southern Belize to have more rivers within two kilometers of the center of a village and a statistically significant correlation between proximity to rivers and villages (Spearman's γ = -0.23; p < 0.05), especially in Stann Creek District (Spearman's γ = -0.82; p < 0.05). CONCLUSIONS: Examination of the distribution of malaria during 10 years indicated transmission varied among geographic areas and among seasons. Additional studies are needed to examine, in more detail, the association between environmental and meteorological factors and malaria transmission. Furthermore, the role of An. darlingi in malaria transmission in Stann Creek needs further study since, of the three main vectors in Belize, An. darlingi has been found strongly associated with rivers

The identification of a suitable irradiation dosage for mutation induction in Zamioculcas zamiifolia (Lodd.) and the polyploidization of Z. zamiifolia and Marsdenia floribunda

Thesis (M.S.)--University of Hawaii at Manoa, 2006.Includes bibliographical references (leaves 81 -87).x, 87 leaves, bound ill. (some col.) 29 c