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10 July 2006, Volume 20 Issue 4 Previous Issue    Next Issue
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研究报告
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研究报告

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Cloning and Structure Analysis of a Panicle-Specific Zinc Finger Protein Gene from Rice(Oryza sativa) LI Yu-sheng ,HUANG Ji ,YU Shan-lin ,HOU Fu-yun ,ZHANG Hong-sheng 2006, 20(4): 343-347 .  Abstract ( )   PDF (887KB) ( )   Through bioinformatics and the RT-PCR assay,a novel zinc finger protein gene,belonging to TFⅢA type,was cloned from rice and designated as OsZPT3-1,which is specifically expressed in rice panicles,but not detected in culms,leaves,anthers and roots at the adult stage.OsZPT3-1 is 1104 bp in length and its complete opening read frame(ORF) is 1092 bp encoding a protein of 363 amino acid residues.The OsZPT3-1 contains three C2H2 zinc finger motifs and only the third zinc finger has a conserved QALGGH sequence,belonging to B-type zinc finger.There was a Leu-rich region with consensus of LXLXL in the C-terminal of OsZPT3-1,which might function as a transcription repressor.Promoter analysis revealed three MADS-box transcription factor recognition sites existing in OsZPT3-1 promoter.Taken together,it can be speculated that OsZPT3-1 may play a key regulatory role in the development of panicle by repressing gene expression under the control of MADS-box transcription factors.

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Morphogenesis,Anatomical Observation and Primary Genetic Analysis of a Multi-Glume Floral Organ Mutant in Rice LI Ai-hong ,WU Ru ,ZHANG Ya-fang ,TANG Wen ,WU Chang-yin ,PAN Xue-biao 2006, 20(4): 348-354 .  Abstract ( )   PDF (1179KB) ( )   A multi-glume(mg) mutant was obtained by screening the T-DNA inserted mutant pool.Anatomical observation revealed that the florets of the mutant showed elongated leafy paleas/lemmas and palea/lemma-like structures,just like multi-glumes.In the 215 observed florets of the mutant,14.27% failed in forming pistils and stamens;23.72% showed extra floret generated on the same rachilla;62.01% of single floret consisted of one to nine stamens and one to three pistils.And that the transparent bulged vesile-like tissue could be observed at the base of filament in some cases.The mutant showed glumaceous lodicules which prevented the florets from opening in natural conditions,and absolute male and female sterility was another obvious characteristics of this mutant.The process of floral organ morphogenesis was investigated using scanning electron microscopy(SEM),and the results showed that no difference in phenotype of floret primordial was found between the wild type and the mutant,but for the mutant,the beginning of stamen and pistil primordial differentiation was later compared with the wide type and the palea/lemma-like structure continually differentiated after the normal palea and lemma had formed.Furthermore,un-equipotent division of floral primordial in the mutant caused the variation in numbers of stamens and pistils.Genetic analyses supported this mutation phenotype was a recessive trait controlled by a single gene and co-segregated with the T-DNA.According to its phenotype,it was deduced the mutant was the result of homeotic conversion from the E loss-of-function.

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Chromosome Walking for Fine Mapping of Xa23 Gene Locus by Using Genomic Libraries Wang Chun-lian,Chen Le-tian,Zeng Chao-qun,Zhang Qun-yu,LIU Pi-qing,LIU Yao-guang,Fan Ying-lun,Zhang Qi 2006, 20(4): 355-360 .  Abstract ( )   PDF (396KB) ( )   To develop closely linked markers for the rice bacterial blight resistance gene Xa23,a TAC library of Minghui 63 and a PAC library of Guanglu′ai 4 were screened using the 0.8 kb PCR-product from rice near iso-genic line CBB23 as probe.The probe DNA was amplified with the primer of the EST marker C189 that is linked to Xa23 gene with a genetic distance of 0.8 cM.Fifteen insert-end-fragments from the obtained seven positive TAC and PAC clones were isolated by enzyme digestion or Tail-PCR.RFLP-Southern blotting analysis showed that seven of the 15 end-fragments displayed polymorphism between CBB23 and the susceptible recurrent parent Jingang 30.Consequently,individual plants from F2 population of(Jingang) 30/CBB23 were further RFLP-surveyed using the seven polymorphic end-fragments 69B,70N,81N,45B,45N,84N and 84B as probes.The results showed that 69B,70N,81N,45B,45N,84N and 84B were linked to the Xa23 gene with genetic distances of 0.4,0.4,0.4,0.5,0.6,0.6 and 1.1 cM,respectively.However,BLASTN analysis against the genome sequence of Nipponbare showed that the physical distances between Xa23 and 69B,70N and 81N were different even though the genetic distances were the same.The Xa23 gene locus was successfully fine mapped with the 7 end-fragment markers.The applicability of this chromosome walking strategy for other crops was discussed.

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SSR Diversity of in-situ and ex-situ Conserved Oryza rufipogon Populations in Jiangyong County of Hunan Province LI Xiao-xiang ,ZHAN Qing-cai ,WEI Xing-hua ,DUAN Yong-hong ,CHEN Zu-wu ,LIU Yong 2006, 20(4): 361-366 .  Abstract ( )   PDF (131KB) ( )   The genetic diversity of Jiangyong wild rice (Oryza rufipogon) populations in ex-situ and in-situ conservation was studied by using SSR assay.The 48 SSR markers showed polymorphic bands.A total of 166 and 119 alleles were detected in the ex-situ(G3) and in-situ(G4) populations,with the average of 3.55 and 2.60 per marker,respectively.In G3 and G4 populations,the percentage of polymorphic loci(P) were 99.4% and 95.2%,the mean number of observed alleles(A) 1.99 and 1.95,the mean effective number of alleles(Ae) 1.428 and 0.508,and gene diversity(He) 0.272 and 0.304,respectively.It indicated that richer genetic variation existed in G4,but some new variants were found in G3,not in G4.Furthermore,43.4% of total variation in G4 was found among the subpopulations,with a mean coefficient of gene differentiation(Gst) 0.434 in a range of 0.156-0.935 among the four subpopulations(G4-1,G4-2,G4-3,G4-4).Beside G4-2 subpopulation,more gene diversity existed within subpopulations than between subpopulations in the in-situ populations,and the order of gene diversity was G4-1>G4-3>G4-4>G4-2.

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Assessment of Uniformity of Major Rice Varieties in China Using Microsatellite Markers YING Jie-zheng ,SHI Yong-feng ,ZHUANG Jie-yun ,XUE Qing-zhong 2006, 20(4): 367-371 .  Abstract ( )   PDF (651KB) ( )   To have a better assessment of the within-variation variation of the major rice varieties in China,41 varieties from two to seven sources were assayed with a set of five well-chosen microsatellite markers,18 varieties(43.90%) of which showed heterogeneity among the different sources with the same name at 1 to 4 loci.Eleven varieties were further selected and analyzed with larger samples containing 50 individuals per variety.Non-uniformity of the varieties varies from 0.0-10.0% with an overall average of 1.67% on average five SSR loci,and the heterogeneity of the markers ranges from 0.36% to 5.45%.It also showed that 6 of the 11 typical rice varieties were completely uniform,and the non-uniformities within varieties across all loci were lower than 5%.Therefore,it is advisable that the sources of the materials should be selected carefully in constructing a microsatellite database,and that the number of markers should be correspondingly increased when identifying some specific materials.

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Genetic Analysis of Male Sterility in Three Photo-Thermo-Sensitive Genic Male Sterile Lines in Rice ZENG Hong-quan ,LIU Yi-bai ,YIN Jian-hua ,ZOU Guo-xing ,PENG Zhi-qin ,YANG Ping ,HUANG Yong-ping ,CHEN Chun-lian 2006, 20(4): 372-378 .  Abstract ( )   PDF (129KB) ( )   Three photo-thermo-sensitive genic male sterile lines(6442S,8011S,1290S) were crossed with five male parent lines(1990,Xinlu B,Ce 64-7,JR2410,R402),and the sterility of the 12 crosses in four generations(P1,P2,F1,F2) was jointly analyzed with the mixed inheritance model developed by Gai.The fittest model of the 12 crosses differed,however,all of them showed B-model or D-model or E-model inheritance;The sterile gene existed in all the crosses but the expression of the gene was diverse in various environments.In the crosses which 1290S acted as the female parent,the genetic effect of cross 1290S/1990 was predominant on additive effect and dominant effect,whereas cross 1290S/Xinlu B on epistasis effect,and the heritabilities of the two crosses were over 94%.In the crosses which 6442S was used as the female parent,the proportions of the additive effect and dominant effect showed high value,with the heritabilities ranged from 73.3% to 99.2%,and there existed polygene heritability in the crosses 6442S/Xinlu B,6442S/R402 and 6442S/1990,with the least value of 0.83% and the highest one 35.5%.In the crosses which 8011S was used as the female parent,the epistasis effect was stronger in crosses 8011S/Ce 64-7 and 8011S/1990,but additive effect and dominant effect in other crosses,and 8011S/R402 and 8011S/1990 showed polygene heritability,with the values of 1.03% and 5.94%,respectively.Among the crosses with 8011S as the parent,the highest heritability was 99.06%(8011S/R402),and the lowest was 67.57% 8011S/Xinlu B.

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Genetic Analyses on Nitrogen-Absorbing Ability and Nitrogen-Utilizing Efficiency of Rice at the Seedling Stage LI Yu-hong ,WANG Zhou-fei ,GUAN Rong-zhan ,WANG Jian-fei ,ZHANG Hong-sheng 2006, 20(4): 379-383 .  Abstract ( )   PDF (109KB) ( )   A RILs population consisting of 220 lines(F8) derived from the cross between rice variety Jiucaiqing(japonica) and IR26 (indica) was evaluated to analyze inheritance of nitrogen-absorbing(NA) ability and physiological use efficiency(NUE) at the seedling stage by using the major gene plus polygene mixed inheritance model.The NO3-absorbency,NH4+ absorbency and NUE of rice seedlings were genetically controlled by genetic mode of two major genes plus polygenes.The heritability values of major genes for NO3-absorbency,NH4+ absorbency and NUE were 63.20%,55.67% and 19.47%,respectively,and the values of polygene for the three traits were 20.64%,0.03% and 67.46%.There were additive and epistasis effects for the NO3-absorbency,epistasis effect for the NH4+ absorbency and cumulative effect for the NUE respectively between each two major genes.The strategy to breed new rice variety with high absorbing ability and use efficiency of nitrogen was discussed.

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Study on the Pigmentation of Anthocyanidin in Pericarp of Black Rice HAN Lei ,WU Xian-jun ,ZHANG Hong-yu ,JIANG Hua ,LI Yun ,WANG Xu-dong 2006, 20(4): 384-388 .  Abstract ( )   PDF (256KB) ( )   By real-scanning through a scanner,the pigmentation of anthocyanidin in pericarp was studied with three black indica varieties during caryopsis development in different days after pollination under natural and artificial controlled conditions.The anthocyanidin of black rice caryopsis synthesizes and pigmentizes only in pericarp,and no anthocyandin was observed in endothelium and aleuronic layer.Anthocyanidin in pericarp begins to pigmentize 3 days after pollination,and increases rapidly 5-6 days after pollination,and the whole caryopsis pericarp is full of anthocyanidin 7 days after pollination.Anthocyanidin firstly pigmentizes at the part of caryopsis away from embryo,then gradually extends to the part near embryo and makes the whole pericarp pigmentized.Anthocyanidin can be independently synthesized and accumulated in all over the pericarp.No transportation of anthocyanidin was observed from cell to cell in different parts of pericarp.Anthocyanidin synthesis needs proper temperature and oxygen,which will fail at low temperature or deficient oxygen.

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Changes in Cooking and Nutritional Qualities of Grains at Different Positions Within a Rice Panicle under Different Nitrogen Levels DONG Ming-hui ,SANG Da-zhi ,WANG Peng ,WANG Xue-ming ,YANG Jian-chang 2006, 20(4): 389-395 .  Abstract ( )   PDF (147KB) ( )   Differences in cooking and nutritional quality characteristics among the grains at different positions within a rice panicle were studied.The characteristics investigated included the distribution of gel consistence(GC),amylose content(AC) and crude protein content(CPC) for different grains in a panicle under different nitrogen levels(0,120,and 240 kg/hm2),by using two rice cultivars,Yangdao 6(indica) and Wuyujing 3(japonica) as tested materials.The grains on the primary and secondary branches at the basal part of a panicle had smaller GC and greater AC than those at the upper or middle part of a panicle.The first of earlier-flowered grains on a secondary branch exhibited the greatest GC,whereas the second of later-flowered grains on a primary branch showed the greatest AC.For Yangdao 6,the CPC in the grains on a primary branch at the middle part of a panicle was lower,contrary to that at the upper or basal part of a panicle.For Wuyujing 3,there was no significant difference in CPC of the grains on the primary and secondary branches among the upper,middle and basal parts of a panicle.GC in the grains was increased,whereas AC was reduced from no nitrogen application(0) to low amount of nitrogen application(120 kg/hm2),and the result was reversed from nitrogen at 120 kg/hm2 level to medium amount of nitrogen application(240 kg/hm2).CPC in grains was increased with the increase of the amount of nitrogen application.

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Effects of Various Nitrogen Fertilizer Treatments on Filling and Respiratory Rate of Rice Caryopsis CHEN Juan ,WANG Zhong ,CHEN Gang ,WANG Yue-xia ,MO Yi-wei 2006, 20(4): 396-400 .  Abstract ( )   PDF (166KB) ( )   Two rice varieties were used as experimental materials to study the effects of N application amount and application time on filling and respiratory rate of rice caryopsis.With N application,the rice caryopsis could maintain higher water content,respiratory rate and dehydrogenase activity in late filling phase,and the course for filling and maintaining higher respiratory rate and dehydrogenase activity of rice caryopsis were prolonged in comparison with no N fertilizer application.More N application at booting was more effective compared to more N application at tillering.

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Effects of Low Temperature on Fatty Acid Composition of Thylakoid Membranes and Lipid Peroxidation in Leaves of Rice Seedlings WANG Ping ,ZHANG Cheng-jun ,CHEN Guo-xiang ,WANG Jing,SHI Da-wei ,LU Chuan-gen ,ZUO Min ,LIU Rong-rong 2006, 20(4): 401-405 .  Abstract ( )   PDF (144KB) ( )   A newly-developed super-high-yielding hybrid rice Liangyoupeijiu and a traditional hybrid rice Shanyou 63(as control) were used to study the effects of low night temperature on leaves,mainly by measuring their lipid peroxidation and fatty acid composition of thylakoid membranes with two treatment temperatures 10°C and 25℃.In Shanyou 63,chlorophyll content in rice leaves was decreased obviously with the duration at low temperature, whereas it did not decrease statistically in Liangyoupeijiu.For both of the two hybrids,the contents of 16:0 and 18:0 components at 10℃ were significantly decreased,but there were no marked changes when treated at 25℃,and the contents of both 16:0 and 18:0 components in Liangyoupeijiu were higher than those in Shanyou 63.The contents of 18:1,18:2 and 18:3 component were increased statistically in both of the two hybrids,but those treated at 25℃ increased smoothly.And the content of 18:3 component increased less than that of 18:2.The IUFA(index of unsaturated fatty acid) of fatty acid was increased in the two hybrids,being lower in Liangyoupeijiu than in Shanyou 63.MDA content of the two hybrids showed a similar changing pattern to O2-· content,but the MDA content in Liangyoupeijiu was not increased statistically.The results indicated that,Liangyoupeijiu may be not sensitive to low temperature,and it may have strong chilling-resistance at the seedling stage.Under the chilling conditions,there was a close relationship between IUFA and lipid peroxidation,and both of them were associated with cold adaptation in rice,which suggested that the IUFA may be an indicator of chilling-resistance.The changes in fatty acid composition and protection system on membranes were the key factor of cold adaptation,especially the latter.

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Effect of Abscisic Acid on Saccharide Metabolism and Related Enzyme Activities in Rice Callus JIANG Hua ,GAO Xiao-ling ,WAN Jia ,CHEN Jing ,WANG Ping-rong ,WANG Xu-dong ,XU Zheng-jun 2006, 20(4): 406-410 .  Abstract ( )   PDF (188KB) ( )   By using the calli of rice(Oryza sativa L.) as materials,the effects of abscisic acid(ABA) on saccharide metabolism and related enzyme activities were studied.ABA treatments promoted the accumulation of starch and non-reducing sugar in the calli,especially under 10-12 mg/L ABA treatments.During the period of rice culture,the contents of starch and non-reducing sugar were also significantly affected by ABA.ABA remarkably decreased the activity of reducing sugar and the ratio of fructose to glucose.Meanwhile, ABA inhibited the activities of phospho-glucose isomerase(PGI) and invertase, increased the activities of phospho-glucose mutase(PGM) and starch phosphorylase,indicating that ABA was the most effective factor in saccharide metabolism and to the related enzyme activities on the 1st to 7th days after treatments.It was presumed that the increased content of non-reducing sugar might be resulted from the enhanced accumulation of non-reducing sugar as well as the inhibited invertase activity by ABA,and the increased starch content might come from the higher activity level of starch phosphorylase,and the decreased ratio of fructose to glucose might be due to the diplex effects of ABA on suppressing PGI and promoting PGM activities.

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Growth Characteristics and Yield of Hybrid Rice under No-tillage and Maize Straw Residue Mulching LIN Xian-qing ,ZHU De-feng 2006, 20(4): 411-416 .  Abstract ( )   PDF (171KB) ( )   A field experiment was conducted to determine the effect of different tillage methods in maize stubble field on growth characteristics and yield of hybrid rice in 2002 and 2003.The tillage methods included ridge culture with no-tillage and maize straw residue mulching(P2),ridge culture without tillage and maize straw residue mulching(P1),and traditional tillage in maize stubble field(CK).Compared with conventional tillage method,rice plants under P2 and P1 had higher white root rate,more root exudate amount,more tillers and dry matter weight,which contributed to increase grain yield by 12.1-20.5% and 7.5-7.7%,respectively.Greater leaf area index,higher leaf chlorophyll content and photosynthetic rate,and more N accumulation were detected under P2 than under P1.There was vigorous growth before flowering and presenility at the maturity stage under P1.

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Effects of Soil Water Potential on Panicle Characters and Yield of Rice in Cold Region ZHENG Gui-ping ,LI Hong-yu ,LIU Li-hua ,LU Yan-dong ,QIAN Yong-de ,TONG Bin ,WANG Bo-lun 2006, 20(4): 417-423 .  Abstract ( )   PDF (172KB) ( )   A pot culture experiment was conducted to study the effects of soil water potentials at ranges from-30 to(-35) kPa,-60 to-65 kPa and 0 kPa(check) during different developmental stages on panicle characters and grain yield by(using) two rice varieties Shangyu 397 and Suijing 3 as materials.The treatments at panicle-formation period had the greatest effect on panicle characters and the panicle number under the treatments was significantly more than that in control.The panicle length,numbers of panicle nodes and branches under the treatments during panicle-formation period were also significantly more than those under the control and the treatments during the other periods.However,the difference of panicle number between two soil water potentials was not significant among all the treatments at each treatment stage.The grain yields under the treatments during panicle-formation period were significantly lower than that in control.Obvious effects of soil water potential on grain yields under the treatments at the tillering stage and one to ten days after heading were founded.Panicle length,numbers of panicle nodes and branches were significantly positively correlated with the yield of the middle-position grain and inferior grain.

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Effects of Genotype and Seeding-Date on Formation of Branches and Spikelets in Rice Panicle CHEN Xiao-rong ,ZHONG Lei ,HE Xiao-peng ,FU Jun-ru ,XIONG Kang ,HE Hao-hua 2006, 20(4): 424-428 .  Abstract ( )   PDF (93KB) ( )   Indexes of the formation of branches and spikelets in rice panicle were investigated after heading with 71 rice genotypes sowed at different dates in the fields,and the effects of genotype and seeding-date on the five indexes and their interrelations were analyzed.There were significant differences in the effect of genotype and seeding-date on the numbers of survived primary branches(SPB),degenerated primary branches(DPB),survived spikelets(SS),differentiated primary branches(PBD),and survived secondary branches(SSB) among the genotypes,and the difference of the five indexes was only related to the given genotype,irrespective of whether it belonged to the hybrid,conventional variety,and male sterile line or not.The SPB,SS,SSB, PBD showed high effect of genotype and low effect of seeding-date whereas DPB displayed high effect of seeding-date.The number of survived spikelets per panicle(namely total grain number per panicle) was highly postively related to SPB,SSB,and PBD but lowly to DPB,which was affected by SPB through the formation of SSB.The effects of genotype and seeding-date in the 71 materials were analyzed synthetically,and their potential of large panicle formation was also evaluated.

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Ammonia Volatilization from Shoots of Different Rice Genotypes with Different Nitrogen Use Efficiency after Flowering WU Xiao-qing ,XU Yang-chun ,SHEN Qi-rong ,GUO Shi-wei 2006, 20(4): 429-433 .  Abstract ( )   PDF (173KB) ( )   Ammonia volatilization from shoots of four rice genotypes(i.e.3010,3030,Wujing 4 and Xidao 11) with different fertilizer-N use efficiency was assessed by close chamber method after flowering.Significant variance of ammonia volatilization from these genotypes was observed in a day,while the diurnal fluctuation law was similar.The amount of ammonia volatilization from 0:00 to 8:00 a.m.was significantly less than that in the daytime.The amount of ammonia volatilized from shoots was higher at flowering than at any other stages.Significant variance could be observed in the total amount of ammonia volatilization from the aboveground of these four genotypes after flowering.There was a significant negative relationship between the utilization rate of nitrogen of rice(y) and the amount of ammonia volatilization(x): y=13.075-0.00968x(r=-0.9913**,n=4).The shoot dry weight of Xidao 11 was the lowest among the four genotypes,however the overground ammonia loss was the highest,suggesting that the difference of shoot biomass was not the main cause of ammonia volatilization from these genotypes.

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Estimating Pigment Contents in Leaves and Panicles of Rice after Milky Ripening by Hyperspectral Vegetation Indices CHEN Wei-jun ,ZHOU Qi-fa ,HUANG Jing-feng 2006, 20(4): 434-439 .  Abstract ( )   PDF (155KB) ( )   A field experiment was carried out to investigate the relationships between the hyperspectral reflectance and pigment(chlorophyll a,b and carotenoids) contents in flag leaf and panicle of two rice cultivars under three nitrogen levels from milky to harvest.Eleven vegetation indices were correlated with the pigment contents in flag leaves and panicles.As a result,the mSR705 and mND705indices were significantly related to the chlorophyll contents,with R2=0.9319(n=48) for leaves and R2=0.9488(n=48) for panicles,respectively.Photochemical reflectance index(PRI) was negatively significantly correlated with the Car/Chl ratio in both flag leaves and panicles(R2=0.7745,n=48),indicating that PRI could be used to predict Car/Chl across different vegetation structures.R760/R500 was also significantly(P=0.05) correlated with Car/Chl in leaves,and carotenoids contents in panicles.It was suggested that mSR705,mND705 and PRI could be used to estimate pigment contents in leaves or panicles of rice,and applied as spectral parameters in rice maturation monitoring.

研究简报

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Agrobacterium tumefaciens-Mediated Transformation of the Pathogen of Ustilaginoidea virens ZHANG Zhen ,DU Xin-fa ,CHAI Rong-yao ,MAO Xue-qin ,QIU Hai-ping ,WANG Yan-li ,WANG Jiao-yu ,SUN Guo-chang 2006, 20(4): 440-442 .  Abstract ( )   PDF (684KB) ( )   Conidia of Ustilaginoidea virens were transformed by a Agrobacterium tumefaciens-mediated transformation(AtMT) system using a binary plasmid vector pBIG2RHPH2-GFP-GUS including HPH gene.AtMT yielded stable hygromycin B-resistant clones(average 390-450 per 106conidia),after pre-culture strain C58C1 with acetosyringone(AS).The presence of the fragment of EGFP gene and HPH gene cassette in the transformants were checked by PCR method,and all tested transformants showed EGFP fluorescence in mycelium under 488 nm wavelength.It suggested that Ustilaginoidea virens was successfully transformed by AtMT method.

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Effects of Effective Microorganisms Continual Application in Paddy Fields in Natural Farming WANG Yan-rong ,Iwaishi SHINJI ,Takaaki MIKI ,HUA Ze-tian ,ZHANG San-yuan ,DAI Gui-jin 2006, 20(4): 443-446 .  Abstract ( )   PDF (125KB) ( )   The accumulated effects of effective microorganisms(EM) continuous application for 9 years in paddy field were studied in nature farming.Under continual application of EM,the soil nutrients changed greatly,and rice growth was also affected,such as delay in heading,prolongation of flowering period and deepening of leaf color.EM application significanly increased rice yield and the effect became greater with the year increasing.In addition,EM application could improve rice taste quality,decrease K and Mg contents,increase amylose content and taste value of rice.Moreover,EM application could control weed germination and growth to some extent.

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Effects of Sublethal Dose of Fipronil on Detoxifying Enzymes in the Larvae of Chilo suppressalis and Sesamia inferens HUANG Cheng-hua ,YAO Hong-wei ,YE Gong-yin ,CHENG Jia-an 2006, 20(4): 447-450 .  Abstract ( )   PDF (75KB) ( )   The LD50values of fipronil to Chilo suppressalis(Walker) and Sesamia inferens(Walker) larvae were 0.1749 μg/g and 10.1352 μg/g,respectively.After the larvae were treated with sublethal dose(LD15) of fipronil,the specific activity and the maximum velocity(vmax) values of carboxylesterase(CaE) and glutathione S-transferase(GST) in the larvae of C.suppressalis and S.inferens were all increased significantly,while those of mixed-functional oxidase(MFO) were decreased.The Michaelis-Menten constant(Km) values of CaE and MFO in C.suppressalis larvae treated with sublethal dose of fipronil were markedly higher than those of the control,while that of GST showed no marked changes.In contrast,the Km values of CaE,GST and MFO in S.inferens larvae treated with sublethal dose of fipronil were high-significantly decreased.It was suggested that the process of fipronil metabolism in the larvae of C.suppressalis and S.inferens might be much different and the difference in substrate affinity of detoxifying enzymes between the two stem borers were possibly resulted in their different susceptibilities to fipronil.

实验技术

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Determination of Several Quality Characteristics of Brown Rice by Near Infrared Transmission Spectroscopy SUN Cheng-xiao ,DUAN Bin-wu ,XIE Li-hong ,CHEN Neng 2006, 20(4): 451-454 .  Abstract ( )   PDF (102KB) ( )   Two hundred and sixty-six brown rice samples were scanned with a FOSS TECATOR infratec 1241 grain analyzer and their grain quality characteristics were also determined by traditional methods.Using WINISI software,the models for predicting several grain quality characteristics of brown rice by near infrared transmission spectroscopy(NITS) were developed.The results indicated that the model for protein content prediction was the best,with the corrected standard error of performance SEP(C) being 0.312 and average determination coefficient of validation(RSQ) being 0.956;reasonable accurate models were also obtained for predicting the amylose content,alkali spreading value,transparency and chalky degree.Their SEP(C) were 1.672,0.389,0.034,4.024 and RSQ were 0.745,0.838,0.797,0.714,respectively.The repeatability of the NITS prediction and the application of the developed models in rice breeding program were also discussed.