Development of microsatellite markers for Dryobalanops aromatica (Dipterocarpaceae), a tropical emergent tree in Southeast Asia

Eight polymorphic microsatellite markers were developed in Dryobalanops aromatica, an emergent tree in tropical rain forests in Southeast Asia, using an enriched library method. For the assessment of microsatellite variation, 36 individuals from a natural population were analysed. The number of alleles per locus ranged from three to 16, with observed heterozygosity of 0.056–0.833 and expected heterozygosity of 0.054–0.882. These microsatellite markers will be useful for studies of population genetics, reproductive ecology and regeneration dynamics of D. aromatica.     

Distribution of greenhouse gases, nitrite, and δ13C of dissolved inorganic carbon in Lake Biwa: Implications for hypolimnetic metabolism

The vertical distribution of dissolved greenhouse gases (CH₄,CO₂ and N₂O), NO ,and ¹³C of CO₂ in Lake Biwa during a stagnantperiod was precisely determined. CO₂ as well as NO was accumulated in the hypolimnion, whereas NO and CH₄concen\-trations were generally higher in theepilimnion than in the hypolimnion. In August, NO andCH₄ were ephemerally accumulated at the thermocline. Theconcentration of CH₄ always exceeded equilibrium with respectto air/water exchange. N₂O was rather uniformly distributed inboth time and space, and remained near equilibrium with respect toair/water exchange. All of these observations are similar to otherstratified, oligotrophic lakes, in which the hypolimnia were welloxygenated. The ¹³C of CO₂ became morenegative with increasing depth, and showed a strong negativecorrelation with apparent oxygen utilization. From the data, the ¹³Cvalue of organic matter decomposed into CO₂ inthe hypolimnion was calculated by isotope mass-balance, and found tobe in a similar range to ¹³C of phytoplankton and benthic algaeand distinctively higher than ¹³C of both terrestrial andsedimentary organic matters. This suggests that autochthonous organicmatter was the major source of CO₂.     

A Model for the Growth of Individuals in Plant Populations Cultivated at Different Concentrations of Fertilizer Solution

The growth of mean individual weight is the joint outcome ofthe growth of the individuals comprising a population. Fromthe growth data of individual weight in radish (Raphanus sativusL. var. radiculus Pers.) populations cultivated at differentconcentrations of ammonium sulphate solution, a deterministicmodel was proposed for integrating individual plant weight intomean weight per plant in a population. The model constructiondepended on the relation between mean individual weight andthe amount of fertilizer supplied to a population, and uponPearson's type VII distribution. The model related the weightof any individual to the amount of fertilizer. The fitness ofthe model to observed data was satisfactory, although the modelwas simple. Using the model, properties of the growth of componentindividuals of a population were examined in relation to thegrowth of mean individual weight. fertilizer, growth, individual, mean, Pearson's type VII distribution, plant weight, population, radish, Raphanus sativus L. var. radicula Pers