Biological characteristics of Ustilaginoidae virens and the screening in vitro of the causal pathogen of false smut of rice and fungicides

Green smut bails were collected from diseased rice panicles and surtace sterilized in sodium chloride for 5 minutes. The orange colored internal tissues were placed on PDA medium kept at 25℃ for 5 d to get pure cultures. PDA plates with the pathogen mycelial pieces in diameter of 5mm were incubated under 9 temperature grades ranged from 13 to 35℃.     

Preliminary studies on radiant spectrum of the leaves of the paddy and upland rice

To study the property of the radiant spectrum(RS),i.e.absorption,reflectance and trans-mission ratio.Four upland rice varieties i.e.Haogelao,Hongkuo—laoshuya,Chengjiang—ludao,and IRAT—109,and four paddy ricevarieties Xifeng,Akihikari,Zhongbai 4,andYuefu were sown at Beijing on dry land in themiddle May,1992 and 1993.The plants weretreated with drought stress during seedling,booting,heading and flowering stages.It wasrainy season or intermittent irrigation duringother period.The RS and the chlorophyll con-tent of the third leave of seedlings and that offlag leave at heading—flowering period weremeasured with UV—190 model spectrometer.The results are shown in Fig 1 and Fig 2.There were little difference of RS in 800-200 mn and chlorophyll content between theleaves of paddy and upland rice during seedlingstage (Fig 1).However,remarkable differ-     

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.     

Report of the joint meeting of the Potato Section of EUCARPIA and the Section Breeding and varietal assessment of the EAPR, 3–7 July, 2000, Warsaw (Poland)

Report

Report of the joint meeting of the Potato Section of EUCARPIA and the Section Breeding and varietal assessment of the EAPR, 3–7 July, 2000, Warsaw (Poland)     

Characterization of Pseudomonas spp.and related bacteria from rice seeds in the subtropics and the tropics

To explore the bacterial diversity for sustain-able management of the major rice diseases,asurvey of bacterial diversity of rice seed wasconducted in Luzon Island of the Philippines(the tropics)and in Zhejiang Province of China(the subtropics),during 1993-1998.One hun-dred sixteen(0.5kg/sample)and 129(1kg/sample)seed samples were collected from the subtropics and the tropics,respectively.Morethan 3000 bacterial isolates were picked and examined under the UV light for their fluores-cence.After colony morphological,pathogeni-cal,and some bacteriological tests,816 non-pathogenic bacteria isolates were selected forfurther identification using a numeric taxono-     

Effects of S3307 on the photosynthesis,the activity of SOD,and MDA content of rice flag leaf

Ｕｎｉｃｏｎａｚｏｌ，（Ｅ）＿１＿（４＿ｃｈｌｏｒｏｐｈｅｎｙｌ）＿４，４＿ｄｉｍｅｔｈｙｌ＿２（１，２，４＿ｔｒｉａｚｏｌ＿ｌ＿ｙｌ）＿１＿ｐｅｎｔｅｎ＿３＿０１，ｎａｍｅｄＳ３３０７，ｉｓａｎｅｗｐｌａｎｔｇｒｏｗｔｈｒｅｔａｒｄａｎｔｔｈａｔｃａｎｒｅｔａｒｄｔｈｅ ｇｒｏｗｔｈｏｆ ｐｌａｎｔｓ，ｍａｋｅ ｐｌａｎｔｄｗａｒｆ，ｐｒｏｍｏｔｅｒｏｏｔａｎｄｔｉｌｌｅｒｇｒｏｗｔｈ，ｄｅｌａｙｔｈｅｓｅｎｅｓｃｅｎｃｅｏｆｌｅａｖｅｓ，ａｎｄｉｎｃｒｅａｓｅｔｈｅｎｅｔｐｈｏｔｏ ｓｙｎｔｈｅ…     

Effects of temperature and pH on the inhibition of Bensulfuron-Methyl(BSM)

Bensulfuron-Methyl(BSM) is a highly active sulfonylurea herbicide that effectively controls most annual and perennial broadleaf or sedge weeds in paddy field. However, the activity of BSM is affected by several evironmental factors. Using corn seedlings as material, we found that under different temperatures     

Elongation and insolubilisation of α-glucans by the action of Neisseria polysaccharea amylosucrase

Amylosucrase (E.C. 2.4.1.4) from Neisseria polysaccharea catalyses a transglycosylation reaction using sucrose as a glucose donor to synthesise an insoluble (1→4)-α-glucan, releasing fructose in the solution. If glycogen is used as a glucosyl unit acceptor, amylosucrase elongates polymer branches from their non-reducing ends. Testing of a large series of acceptors with various molar masses, glycosidic linkages, branching degrees and solubilities showed that chain elongation occurred only on polymers with (1→4)-α- or (1→4)-α- and (1→6)-α- linkages. Synthesis yields were better for completely soluble polymers (1.45 glucosyl units grafted per glucosyl unit for polymers with (1→4)-α- and (1→6)-α- linkages), than for partially soluble polymers (0.27–0.97 glucosyl units grafted per glucosyl unit for polymers with either (1→4)-α- linkages or (1→4)-α- and (1→6)-α- linkages). Elongation occurred randomly at the non-reducing ends of some external chains. Elongation of soluble branched molecules led to rapid gel formation favourable to gelation control inside suspensions and solutions. These polymers showed resistant starch contents (22% (w/w) to 57%) after elongation with amylosucrase.     

A study of the measurement of fracture toughness in cohesive soil – relationship between the size of initial crack and diameter of specimen

The phenomenon of hydraulic fracturing is considered to be one of the causes of leakage in fill-type dams. In recent years, it has been found that an estimate of the fracture toughness of a given type of soil could be used as an indicator of the soils resistance to hydraulic fracturing. One of the problems encountered in its estimation is the assumption that fracture toughness has been theoretically defined for samples of infinite sizes. In this study, laboratory tests were conducted to determine the fracture toughness of samples (of the same size) prepared with initial cracks of various lengths. The main objective was to investigate the relationship of the initial crack length to fracture toughness. The stress distribution around the crack tip for each laboratory test sample was estimated by FEM analysis and by a theoretical equation. These analytical results corresponded reasonably well to results from laboratory tests to determine the appropriate length of the initial crack for the test specimens.     

RFLP tagging of a gene for giant embryo and the integration of chromosome 7 of rice

Lipid content of rice grain was lower than that of corn and other oil crops, but it was rich in the content of unsaturated lopacid. As all the lipid was stored in embryo, one of the promising way to raise its content is to increase the embryo size. Genetic etidies on giant embryo was therefore of great importance. In this experiment, Kinmaze, a japonica giant embryo mutant derived from Japan, and an indica variety Nanjing 11 were used as parents to construct a F_2 population of 58 plants. In combination with eight restriction enzymes (EcoR Ⅰ, EcoR Ⅴ, Dra Ⅰ, Xba Ⅰ, Hind Ⅲ, BamH Ⅰ, Bgl Ⅱ, andSca Ⅰ), 262 DNA clones were used to detect the RFLP's of the parents, of which 73.2% detected polymorphism between the two parents. Seventy-four polymorphism clones were used to analyze the RFLP's of 58 F_2 individuals. Linkage analysis was then performed with the computer package MAPMAKER (Lander et al, 1987). Twelve linkage groups were constructed, among which RFLP markers RG678 and RE395 on chromo     

Studies on the relationship between the changes of the endogenous scavengers of active oxygen and resistance in hybrid rice under temperature stress

The seedlings of indica hybrid rice Weiyou 49 and Weiyou 28 were exposed to 1℃ and 40℃ .and the changes of activity (content) of superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), ascorbic acid (ASA), glutathione (GSH),malondialdehyde (MDA) and leakage of electrolytes (%) were measured.     

Characterization and online detection of surfactin isomers based on HPLC-MS(n) analyses and their inhibitory effects on the overproduction of nitric oxide and the release of TNF-α and IL-6 in LPS-induced macrophages

A rapid method for characterization and online detection of surfactin isomers was developed based on HPLC-MS(n) (n = 1, 2, 3) analyses, and many surfactin isomers were detected and characterized from the bioactive fraction of the mangrove bacterium Bacillus sp. Inhibitory activities of surfactin isomers on the overproduction of nitric oxide and the release of TNF-α and IL-6 in LPS-induced macrophages were systematically investigated. It was revealed that the surfactin isomers showed strong inhibitory properties on the overproduction of nitric oxide and the release of IL-6 on LPS-induced murine macrophage cell RAW264.7 with IC(50) values ranging from 1.0 to 7.0 μM. Structure-activity relationship (SAR) studies revealed that the existence of the free carboxyl group in the structure of surfactin isomers was crucial. These findings will be very helpful for the development of this novel kind of natural product as new anti-inflammatory agents.     

Insecticide resistance and activities of relative enzymes in different populations of the white-backed planthopper

Ｗｈｉｔｅｂａｃｋｅｄｐｌａｎｔｈｏｐｐｅｒ（ＷＢＰＨ），Ｓｏｇａｔｅｌｌａｆｕｒｃｉｆｅｒａ（Ｈｏｒｖａｔｈ），ｉｓｏｎｅｏｆｔｈｅｍｏｓｔｄｅｖａｓｔａｔｉｎｇｉｎｓｅｃｔｐｅｓｔｓｏｎｒｉｃｅｉｎＡｓｉａ．Ｉｔｓｃｏｎｔｒｏｌｍａｉｎｌｙｄｅｐｅｎｄｅｄｏｎｔｈｅｃｈｅｍｉｃａｌｐｅｓｔｉｃｉｄｅｓ．Ｓｕｒｖｅｙｓｏｆｉｎｓｅｃｔｉｃｉｄｅｓｕｓｃｅｐｔｉｂｉｌｉｔｙｒｅｖｅａｌｅｄｔｈａｔｏｒｇａｎｏｐｈｏｓ ｐｈｏｒｕｓａｎｄｃａｒｂａｍａｔｅｒｅｓｉｓｔａｎｃｅｈａｓｅｍｅｒｇｅｄｓ…     

Effects of spermine and spermidine on the germination of rice seeds under different temperatures

Polyamine , including putrescine (Put) , spermidine(Spd), and spermine(Spm) , are a kind of regulating substances known extensively inhigher plants at present. Different results have been reported on the relationship between polyamines and seed germination (wheat, tobacco and potato). This study investigated the effects of spormine and spermidine on germination of rice seeds.