Leaf Vein Variations and Gene Control Mode of Cyclamen Hederifolium

In order to explore the heredity of leaf veins of Cyclamen Hederifolium and to breed excellent varieties, selling measurement for six types of different leaf veins were carried out and the genetie constitutions of leaf veins were studied according to the separation conditions of their progenies. The results showed that the inbred progenies of B or M types were B or M types with a percentage of 100% while the progenies of F, H, X and L types had character segregations. The separa- tion law illustrated that leaf veins of Cyclamen Hederifolium were eontrolled by minor multiple genes and each locus was consisted of a pair of alleles, RL of Rn. RL was responsible for the green phenotype of leaves and RB was responsible for the silvery white phenotype of leaves, leaves were deep green when the genotype of the locus was RLRL ; leaves were green when the genotype was RLRB ; leaves were silvery white when the genotype was RBRB. The aggregafive pattern of each locus formed different leaf vein types. The gene control modes of leaf vein variations were the basis for the breeding of excellent varieties of Cyclamen Hederifolium.

Investigation on the radioactivity levels of seawater,sediments,and biota in Daya Bay,China

Objective:To investigate the radioactivity levels of seawater,sediments,and biota in the Daya Bay sea area,China,in order to establish the radioactivity baseline values,and provide basic data for the assessment of potential radiological risks that might result from the application of nuclear technology or human activities.Methods:Samples of seawater,sediments,and biota were collected from the Daya Bay sea area and analyzed.Their radioactivity baseline data were then compared with information from other regions in China and around the world reported in related literature.Results:For the seawater samples,the activity concentrations of natural radionuclide ^(40)K were 9.9-10.4 Bq/L,while ^(238)U,226Ra,^(210)Pb,^(137)Cs,and ^(110)Ag^(m) were below the minimum detectable activity(MDA).Regarding the sediment samples,the activity concentrations of ^(238)U,^(228)Ra,^(226)Ra,^(210)Pb,^(40)K,and ^(137)Cs were 38.1-40.4,49.1-53.7,32.6-38.6,59-95,590-650,and 0.48-0.88 Bq/(kg dry weight),respectively,while ^(110)Agm was below the MDA.For the marine shrimps in the biota samples,the activity concentrations of ^(228)Ra,^(226)Ra,^(40)K,and ^(137)Cs were 1.14-2.75,0.17-0.43,63-76,and 0.038-0.045 Bq/(kg wet weight),respectively,while ^(238)U,^(210)Pb,and ^(110)Agm were all below the MDA.Furthermore,for the marine fishes in the biota samples,the activity concentrations of ^(228)Ra,^(226)Ra,^(210)Pb,^(40)K,and ^(137)Cs were 2.1-19.7,0.32-3.78,<2.2-2.8,59-70,and<0.007-0.026 Bq/(kg wet weight),respectively,while ^(238)U and ^(110)Ag^(m) were all below the MDA.^(228)Ra was found to be concentrated in Osteomugil ophuyseni with 19.7 Bq/(kg wet weight).Conclusions:The radioactivity levels of seawater and marine sediments in the Daya Bay sea area are within the range of the normal background values.Osteomugil ophuyseni exhibited higher concentrations of ^(228)Ra than other species in this study,while the other species in the biota show no significant difference in the radioactivity levels from data in relevant literature.