A remarkable progress in breeding new rice line through gene engineering

Much progress has been made in the research of breeding new rice line through gene engineering by Life Science College of Fudan Univ, Shanghai, and the Plant Science Res Inst of Shanghai Acad of Agri. It was the first time internationally that the research adopted a man-combined gene, taking agrobacterium as car-

Rice Drying,Storage and Processing:Effects of Post-Harvest Operations on Grain Quality

Various post-harvest processes of rice are commonly employed,especially during the off-season,to ensure its consumption feasibility,which often affect the grain quality.Different forms of drying,storage and processing of rice are evaluated to identify their effects on grain quality.Microwave drying has emerged as an alternative to the widely-used intermittent-drying and fixed-bed-dryer methods of drying paddy rice.Control of drying-air temperatures(between 40℃ and 60℃)according to the rice variety can improve quality,especially for exotic varieties.Keeping stored grain in hygroscopic balance,with water content between 11%to 15%,at temperatures between 16℃ and 20℃ and with intergranular relative humidity near 60%,allows 12 months of storage in a controlled environment without significant deterioration.Other innovations,notably the application of artificial refrigeration to grain stored in bulk in vertical cylindrical silos and the use of impermeable packaging for storage,ensure the conservation of grain mass.The different stages and equipments used to obtain polished,brown and parboiled rice result in significant changes in the nutritional value of rice because of the removal of the outermost layers of the grains.Polishing reduces the nutritional value and physical homogeneity of rice.Brown rice retains more bioactive compounds and nutrients because it does not lose the outer layer of the grains in the polishing processes.Parboiled rice,although less nutritious than brown rice,has better grain integrity and milling yield and less loss of nutrients than white rice.

Response of rice to inoculation with genetic engineered strains of associative diazotrophs

Enhancement of nitrogen fixation in the rhizo-sphere of cereals has attracted a wide interestin biological and agricultural research,insteadof chemicals,for supplying higher plants withcombined nitrogen.Bacteria in association withrice plant.s were sensitive to the surroundingfactors in the soil,such as NH~+ or O,whichrepressed associative nitrogen fixation between

Ray Wu,Cornell's acclaimed pioneer of genetic engineering and developer of insect-resistant rice

ITHACA, N.Y. -- Ray J. Wu, Cornell University professor of molecular biology and genetics, who was widely recog-nized as one of the fathers of genetic engineering and who developed and sought to feed the world with a higher yield-ing rice that resists insects and drought, died of cardiac arrest in Ithaca, Feb. 10.

Use of a dietary exposure system for screening of insecticidal compounds for their toxicity to the planthopper Laodelphax striatellus

We developed a dietary exposure assay for screening insecticidal compounds for their toxicity and for assessing the side effects of insecticidal proteins produced by genetically engineered （GE） plants on the planthopper Laodelphax striatellus Fallen. The fitness bioassay confirmed that the diet fulfills the requirements to be used in the dietary exposure system. To validate the efficacy of the dietary exposure system, nymphs of L. striatellus were fed diets treated with different concentrations of an inorganic stomach poison, potassium arsenate （PA）, or a cysteine protease inhibitor, E-64. The results showed that with increasing concentrations of E-64, the larval development time was prolonged, the adult weight was reduced and the survival rate of L. striatellus was decreased. Similarly the survival rates of L. striatellus consistently decreased with increasing PA content in the diet. The data indicate that the dietary exposure assay is able to detect the effects of insecticidal compounds on L. striatellus. Subsequently, this assay was successfully used for assessing the potential toxicity of Cry2Aa. The results showed that L. striatellus larvae were not negatively affected when fed the artificial diet containing purified Cry2Aa at 300 μg/g diet. In the assay, the stability and bioactivity of crystal （Cry） proteins in the food sources were confirmed by enzyme-linked immunosorbent assay and sensitive-insect bioassays. These results show that L. striatellus is not sensitive to Cry2Aa. We conclude that the dietary exposure system is valid and useful for assessing the toxicity of insecticidal compounds produced by GE plants on planthoppers.