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[Objective] This study was conducted to investigate the crossbreeding method for Chinese water chestnut. [Method] The growth of Chinese water chestnut stalk and inflorescence was observed. Chinese water chestnut flowering law and stamen and pistil growth were investigated in an artificial pollination experiment.[Result] Stamens and pistils reached their full bloom stages when the flower stalk lengths were approximate 37.0 and 46.9 cm, respectively, with a height difference of 9.84 cm and time difference of 28.5 h; and 9:00-11:00 a.m. was the optimal period for artificial pollination. Seven hours after artificial pollination, pistils wilted rapidly.The seed setting rates under artificial pollination and a natural condition was 43% and 15.5%, respectively. [Conclusion] The time difference between the full bloom stages of stamens and pistils is crucial to the success of artificial pollination of Chinese water chestnut. The seed setting rate under artificial pollination is much higher than that under a natural condition. [ABSTRACT FROM AUTHOR]

With the forms of pistil stigma of "Guiti 2" Chinese water chestnut cnltivar during the pollination as the object of observation, we reveal the pollination process of Chinese water chestnut from the microscopic point of view, to provide reference for Chinese water chestnut crossbreeding. The results show that the Chinese water chestnut pistil has 2-4 stigmas which present white filament and vascular bundle forms, and the vessels on epidermis are thick with long translucent branched hairs; after pollination, pollen grains are tightly bound on branched hairs, and after identification, the pollen tube can penetrate branched hairs. continue to grow, and transfer the genetic material in pollen to vascular" bundle. [ABSTRACT FROM AUTHOR]

Particles from ambient air and combustion sources including vehicle emission, coal combustion and biomass burning were collected and chemically pretreated with the purpose of obtaining isolated BC (black carbon) samples. TEM (transmission electron microscopy) results indicate that BC from combustion sources shows various patterns, and airborne BC appears spherical and about 50 nm in diameter with a homogeneous surface and turbostratic structure. The BET (Barrett-Emmett-Teller) results suggest that the surface areas of these BC particles fall in the range of 3-23 m²/g, with a total pore volume of 0.03-0.05 cm³/g and a mean pore diameter of 7-53 nm. The nitrogen adsorption-desorption isotherms are indicative of the accumulation mode and uniform pore size. O2-TPO (temperature programmed oxidation) profiles suggest that the airborne BC oxidation could be classified as the oxidation of amorphous carbon, which falls in the range of 406-490°C with peaks at 418, 423 and 475°C, respectively. Generally, the BC characteristics and source analysis suggest that airborne BC most likely comes from diesel vehicle emission at this site. [ABSTRACT FROM AUTHOR]