Ultraviolet-B Radiation Alters Soybean Growth and Seed Quality

Research on the effects of ultraviolet-B (UV-B) radiation on soybean seed quality is limited. The objective of this study was to quantify UV-B doses, 0, 5, 10 & 15 kJ•m–2•d–1, on soybean growth and seed quality. The experiment was conducted in the Soil-Plant-Atmosphere-Research (SPAR) facility. Chambers located at the R.R. Foil Plant Science Research Facility of Mississippi State University, Mississippi, USA, were used. Each SPAR chamber consists of a steel soil bin to accommodate the root system, a Plexiglas chamber to accommodate plant canopy and a heating, and cooling system connected to air ducts that pass conditioned air to cause leaf flutter through the plant canopy. The SPAR units, supported by an environmental monitoring and control systems, are networked to provide automatic acquisition and storage of the data, monitored every 10 seconds throughout the day and night. Soybean cultivar Pioneer 93Y92 (maturity group IV, Roundup Ready) was used in the study. The desired UV-B radiation was supplied by square-wave UV-B supplementation systems under near ambient PAR and delivered to plants for eight hours, each day, from 08:00 to 16:00 h by eight fluorescent UV-313 lamps. The results showed that increased UV-B did not influence many of the growth parameters because the treatments were imposed at mid-fruiting period. Seed quality parameters that are important for seed industry and human and animal nutrition were all affected by UV-B. Protein and palmitic and oleic acids declined linearly, while oil and linoleic and linolenic acid contents increased with increased UV-B. Sucrose, stachyose, and stearic acid contents showed quadratic trends, increased to about 4 - 5 kJ of UV-B and declined at higher doses. Thus, both current and projected UV-B radiation levels can modify soybean growth and seed quality. The functional algorithms developed in this study could be useful to develop UV-B- specific sub-models for soybean farm management and in policy decision areas.

Preliminary Study on Production Performance of Different Varieties of Forage Mulberry

A comparative study was conducted on four mulberry（ Morus alba） varieties（ lines） in Hunan dry land from the aspects of production performance,nutritional composition and amino acids content. The result showed that the four mulberry varieties all adjusted well to soil,climate and other natural conditions in Hunan province,presenting good growth. The dry matter content of four varieties（ lines） was above 25% and the crude protein content was more than 22%. Although the crude protein and total amino acid content of four mulberry varieties were lower than that of soybean powder,the proportion of various amino acids tended to be consistent,so mulberry leaf was very comprehensive in nutrition as an animal feed. Yuesang 11 had the highest fresh yield and crude protein of 14. 28 t / hm^2 and23. 22% respectively; Guisangyou 12 had the highest total amino acid content of 19. 58%. There were differences among four varieties,but each variety had its own advantages,so they all had good popularization value.