Agricultural Application of Multi-functional Leaf Vegetables Light-conversion Film

[Objective] The aim was to detect property of light-conversion agricultural films in order to resolve problems existing of greenhouses and in cultivation of out- of-season vegetables. [Method] Light-conversion films and common films were com- pared in terms Of light, air and soil temperatures. [Result] Vegetable greenhouse performed better in transmission of light, which would also improve air and soil tem- perature. [Conclusion] The comprehensive properties of vegetable light-conversion films proved better compared with common greenhouse, which improves light condi- tions for crops.

Influence of Potassium Fertilization on Yield and Quality of Foliar Vegetable Crops

Over a period of two years , field experiments were conducted on four silty loam soils grown with foliar vegetable crops including Chinese cabbage (Brassica pekinensis Rupr., cv. Lu-Bai 3), autumn greens (B. chinensis L., cv. Piao-Geng-Bai), winter greens (B. var. rosularis Tsen et Lee, cv. You-Dong-Er), and summer greens (B. chinensis L., cv. Zao-Shu 5), respectively. Each experiment included one CK treatment without K, N and P fertilizers applied, and four treatments with from low to high doses, 0-300 kg hm-2 for Chinese cabbage, 0-150 kg hm-2 for autumn and winter greens and 0-180 kg hm-2 for summer greens, of K fertilizers in the form of sulfate of potash (SOP) applied together with N and P fertilizers. One treatment of K fertilizer in the form of muriate of potash (MOP) applied at high levels (150 or 180 kg hm-2) together with N and P fertilizers was included in the experiments of autumn, winter and summer greens , respectively, in order to compare the effects of SOP and MOP. The market yields of the tested crops increased significantly with the increasing rate of K application. The crops supplied with K fertilizers yielded more stably as the CV% of their yields decreased with the rate of K application. K fertilization increased not only K contents but also the amounts of N, P and K absorbed in shoots of autumn, winter and summer greens, which were statistically significantly correlated to their yields. It can also be found that potassium improved the quality of the foliar vegetable crops as their dry mater contents were generally increased and Vc contents obviously increased and nitrate contents markedly decreased. As compared to MOP, SOP was more effective on the yields and quality of autumn, winter and summer greens at the high levels of fertilization.

Newly Discovered Virus Associated Enzyme Capable of Alteration of Nucleic Acid Structures through Phosphotriester/-Diester Bonds

A newly discovered enzyme, that can catalyze the formation of phosphotriester/-diester bonds between nucleic acids, was found to be associated with plant and animal viruses; （i.e. southern bean mosaic virus, brome mosaic virus, influenza virus, avian virus and mouse retrovirus）. A partially purified enzyme from maize developing endosperms was prepared through 15%-35% ammonium sulfate fractionation, DEAE-cellulose anion exchange column chromatography and Sephadex GI50 gel filtration. The enzyme preparation was then used to demonstrate its main functional characteristics. The enzyme can use varieties of short and long chain length of nucleotides as substrates. However, the enzyme requires at least a minimum of 3 to 4 units of nucleotide chain length for the reaction to occur. The enzyme activity shows an optimum reaction in 50 mM sodium acetate buffer at pH 5.4 and is significantly inhibited by 6-azauridine as compared to other nucleotide analogs. By analyzing the data documented in literature and the results from the present study of the association of this enzyme with viruses and the distinctive inhibitory effect of 6-azauridine, it is speculated that this enzyme is likely associated with many other plant and animal viruses. The association of this enzyme on the surface of virus particles can be explored as a common antigen for developing a versatile antiviral vaccine.