Mechanism of immunization of rice seedlings

In saline paddy soil in the north of China, the technique of immunization of rice nursery (IRN) was applied in 1990‘s and succesfuully met the production needs. It had more advantages than paddy soil land nursery (PSLN).     

Development of Chinese near-isogenic lines of rice and their differentiating ability of pathogenic races of blast fun-gus

To use common differential varietiesin the world, a set of internationaldifferential varieties, including 6 in-dica and 2 japonica rice varieties,were set up in the midddle of 1960s;in 1976, a set of differential varietiescmposed of 9 japonica varieties withknown resistance gene were estab-lished; and later a set ofnear-isogenic lines (NILs), 4 lines     

Influence of nitrogen on relative parasitic fitness of cultivar-race combinations of rice blast

Rice blast, caused by Magnaporthe grisea, is one of the most important rice diseases in China. Resistance breakdown often happened, especially in the field supplied with high nitrogen fertilizer. In the simulation study on race dynamics and cultivar-race interaction on population level, the influence of nitrogen on the relative parasitic fittness of cultivar-race combinations should be realized quantitative-ly.     

Effect of desiccation on regeneration frequency of green plantlets and some biochemical properties of calli of wild rice

Wild rice is an important resource of useful genes to rice breeders. However, low regeneration frequency is an obstacle to use the valuable genes. We used desiccation to improve the regeneration frequency and studied the biochemical changes of calli of wild rice after desiccation,     

Serological specificity of leaf streak pathogen of rice

The leaf streak of rice is one of the seedborne and quarantine bacterial disease in China. The rice seeds must be strictly inspected to prevent the disease from spreading. The serological test is a rapid and accurate method of identifying seedborne bacterial plant pathogens. But the specificity and thus reliability of any serological method depend first on the specificity of the antiserum. Therefore, a high specificity of antiserum is always required for and has become a key in detecting the leaf streak pathogen in rice seeds. The present study was conducted on the method of improving the specificity. Two group of antigen, the yellow and white proteins, were extracted from the cells of Xanthornonas oryzae pv. oryzicola by the methods of stepwise precipitation with ammonium sulfate and differential centrifugation. Antiserum A and B against the yellow and white proteins were each produced in white rabbit immunized with the proteins respectively. The tittle of the two antiserum were the same(1: 6400).     

Levels of β-carotene and effects of processing on selected fruits and vegetables of the arid zone of India

Some locally available fruits and vegetables of the arid zone of Rajasthanwere analyzed for their -carotene content; the selected fruits and vegetables were: Dansra (Rhus myserensis), Kachri (Cucumis collosus), fruit Kachri (Cucumis collosus), Kair (Capparisdecidua) and Sanghri (Prosopis cineriria). The -carotene contents of the samples were estimated in fresh and various processed states (blanched, dried and roasted). The results showed the heat lability of -carotene. Among the samples, kair was found to be the richest source of -carotene. Variety, too, had an impact on the content of this fat soluble vitamin.     

AMMI analysis of interaction of genotype and environment in chalkiness of indica rice

Chalkiness is an unpleasant trait for rice con-sumer. which is known to be controlled geneti-cally and affected by environment during grainmaturing. We used the model of Additive MainEffects and Multiplieative Interaction (AMMI)for interpreting the result of genotype by env-iornment interaction (G×E) in the chalkinessof indica rice varieties.     

Grain filling patterns of new plant type of rice

Poor grain filling is one of the major factors af-fecting the realization of yield potential in newplant type(NPT)of rice.To study the grainfilling pattern of NPT lines and its relationshipto grain filling percentage,experiment wasconducted at IRRI in 1998 wet season,usingthree NPT lines(IR65600-42-5-2,IR65600-127-6-2-3,and IR65598-112-2,javanica ortropical japonica)and one indica vatiety,IR72(CK).Grain-filling pattern was determined bymeasuring the grain-filling rate of superior andinferior spikelets every other 3 d after flower- ing.Three grain-filling patterns were found:     

Comparison of four methods of DNA extraction from rice

Polyphenols, teroens, and resins make it difficult to obtain high quality genomic DNA from rice. Four extraction methods were compared in our study, and CTAB precipitation was the most practical one.Materials used were old leaves from F5 transgenic rice in Hainan and fresh leaves from F5 transgenic rice in Kunming.Procedures of the four methods were as follows:1. Basical method: powder 1 g old or new leaves → added 2 ml extraction solution (100 mmol/ L     

A First Class Award of the Ministry of Agriculture

Study on the behaviour and mechanism acoustic communication (AC) in rice planthoppers (RPHs) have been conducted at CNRRI and Hangzhou Applied Acoustic Research Institute since 1986. Researchers have developed techniques for monitoring and playing back the acoustic signal (AS) of RPHs, and have made important breakthroughs in several aspects of AC.     

Preliminary study on effects of magnetizing seeds of rice

Magnetizing seeds of crops has been a new agrophysical technique in recent years. The experiment of magnetized rice seeds by Seed-Magnetizer was conducted in Yuping Dongzu Autonomous County, Guizhou Province, China in 1991. The seeds of three rice varieties (Wenyou 3, Shuanggui and Teqing) were treated with SG-I Seed-Magnetizer.They passed through the Seed-Magnetizer with the passing rate 4000g / min for three separate times. The magnetic field gradient was 10t/m and the magnetic flux 6.5×10~4 t / m~2. And then, the magnetized seeds and non-magnetized seeds (CK) were simultaneously sowed on Apr 24, transplanted on     

Variation of rate of exserted stigma in P（T） GMS lines of rice

Rate of exserted stigmas (RES), ie. the ratio of glumes with exserted stigmas to the total glumes is one of the most important characteristics which affects the out-crossing rate of its combinations. Sixteen P(T) GMS lines with different ecotypes were used to study the variations of RES during their stable sterile period in Wuhan from 1992—1993. Ten healthy panicles were randomly selected at full anthesis. Their colour and the number of glumes showing one-side or two-side exserted of stigmas were investigated. Table 1 showed that there were a great variations of RES among the 16 lines tested in two consecutive years (c.v.=43.38%) and among the     

Effects of EGF on seed-setting and yield of rice

Intersubspecies hybrid rice have strong heterosis but low seed-setting rate, Researches have showed that most of unfilled and partiallyfilled grains occurred in late-flowering spikelets on the base of a panicle, which usually maintain quiescent state for a period after flowering.     

Analysis of inheritance of scented rice variety Shenxiangjing 4

We analyzed the inheritance of fragrance bysoaking rice grains or leafblades in 17g/l KOHsolution, using scented rice (Shengxiangjing 4)and non-scented rice (Huxuan 19 and Lao-laiqing) as materials. The F_1 plants of various crosses did notpresent fragrance. In the F_2 the segregating ra-tio of fragrance and non-fragrance plants and