Distribution of essential oils in leaf tissue of an F2 population of Citrus
SummaryThe identification and distribution of 17 mono- and sesquiterpenes in an F2 population produced from selfing of an interspecific F1 hybrid is presented. A mode of inheritance for most of these components is attempted, percentages of leaf oil components and a correlation matrix are given.
The Genetic Basis for the Conversion of Menthone to Menthol in Japanese Mint.
HE major components of Mentha oils are a principal ketone, and its related alcohol and ester. Since these compounds account for 75-85 percent of the oil by weight, an elementary genetic understanding of their origin and relationship would seem important to any plant breeding work. In this paper, we wish to consider the genetic relationship between the ketone (menthone) and its related alcohol (menthol), using Mentha aruensis L. var. piperascens Briq. 2n = 96 (Japanese mint) as the low menthone-high mentho1 parent. For a high menthone-low menthol parent (nonmentliol by odor), we chose fertile menthone-odored SI strains of either M . spicata L. (2n = 48) or M . crispa L. (2n = 48). Most So strains of these species have carvone and a spearmint odor. MURRAY and REITSEMA (1954) have shown that carvone ( C ) is dominant to menthone ( c ) . SIEVERS, LOWMAN, and RUTTLE (1945) have previously reported that Japanese mint crossed to M . spicata L. gave several hybrids having menthol, and they further investigated the commercial value of these plants. Recently, hybrids of this cross have been studied by IKEDA and UDO (1957). They found menthol hybrids and also hybrids with carvone, the ketone of spearmint. While segregation was known to exist in these interspecific hybrids, a genetic analysis had not been undertaken.
Evaluation of Lapping Grains based on Shape Characteristics.
The shape and size of abrasive grains during lapping varies complicately and irregularly. In this study, the aspect ratio of grain size and the fractal dimension of the grain external form were used as shape characteristics of grain in order to evaluate grains with lapping time. The results obtained are summarized as follows : (1)The fractal dimension increases due to microscopic fracture and decreases due to macroscopic fracture or attritious wear. (2)The aspect ratio and the fractal dimension, which are grain shape characteristicsis of the macroscopic shape and the microscopic surface complication of grain respectively, can be used for evaluating grain shape variation during lapping.