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10 July 2004, Volume 18 Issue 4 Previous Issue    Next Issue
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研究报告
实验技术
综述与专论
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研究报告

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Endosperm Development in Autotetraploid Rice:The Fusion of Polar Nuclei and the Formation of Endosperm Cell Wall WANG Lan,LIU Xiang-dong,LU Yong-gen ,FENG Jiu-huan ,XU Xue-bin ,XU Shi-xiong(S. Y. Zee) 2004, 18(4): 281-289 .  Abstract ( )   PDF (4301KB) ( )   By using the laser scanning confocal microscopy and plastic (Leica 7022 histeresin embedding kit) semi thin sectioning technique, comparative studies on the fusion of polar nuclei and the formation of the wall of endosperm cells in autotetraploid and diploid rice were carried out. Two types of ovaries were observed in the autotetraploid. One type displayed normal process of polar nuclei fusion and further development of free nuclei similar to those in ovaries in the diploid. The other showed many kinds of abnormal development of polar nuclei, including non fertilization, single fertilization, polar nuclei fusion without mitosis and non synchronization of endosperm nuclei. The development of endosperm cell wall in autotetraploid was the same as that in diploid. The wall ingrowths of embryo sac near the micropylar end produced walls of endosperm cell firstly vertically at right angle to the embryo sac wall. These walls ran parallel to each other initially and extended towards the endosperm. As to the cell wall situated in the middle of the endosperm, some of them originated from phragmoplast, but others appeared to have originated randomly without the formation of an obvious phragmoplast. Some abnormal ovaries were found in autotetraploid and they all showed abnormal cell wall development in their endosperm. Abnormal fertilization of polar nuclei and further development of endosperm may cause the decrease of seed set in autotetraploid rice.

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Cloning and Expression of Promoter Fragment of RSG6, an Abundantly Expressed Gene in Rice Sperm Cells LAN Li qiong,MIAO Chen*,BAI Jie,XU Ying,WANG Sheng hua,TANG Lin,YAN Fang,CHEN Fang** 2004, 18(4): 290-296 .  Abstract ( )   PDF (1185KB) ( )   Specific primers were designed according to the published genomic sequences of rice in GenBank and RSG6 gene sequence of rice sperm cells. Two 5′upstream sequence of RSG6,1 408 bp and 1 173 bp, were amplified by polymerase chain reaction(PCR) technique from DNA template of rice variety Guichao 2 and were named as PB and PS respectively. The results analyzed by NCBI BLAST and internet software PLANT CARE indicated that PB and PS are rather similar, and both fragments had many conservative promoter elements of higher plants, which suggested that PB and PS might perform their function to promote the specific expression of RSG6 in rice sperm cells. Four deletion fragments, PB1, PB2, PS1 and PS2 were produced by PCR. After entry vector pBI221 PB1, pBI221 PB2, pBI221 PS1 and pBI221 PS2 were constructed, four plant expression vectors, pBIN GUSB1, pBIN GUSB2, pBIN GUSS1 and pBIN GUSS2 were then constructed. Recombined vectors were transferred into Agrobacterium tumefaciens EHA105, and the latter were used to transform the leaves and pollen of tobacco. GUS transient expression demonstrated that the four deletion fragments could work as promoter.

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Inheritance of a New Cytoplasm Photo/Thermo-Sensitive Genic Male Sterile Line B06S in Rice HE Hao hua,HUANG Wen xin,PENG Xiao song,ZHU Chang lan,LIU Yi bai 2004, 18(4): 297-302 .  Abstract ( )   PDF (194KB) ( )   The major sterile genes of a new cytoplasm photo/thermo sensitive genic male sterile line B06S in rice were analyzed by mixture distribution theory. The results indicated that a pair of major sterile nuclear genes with larger genetic effects controlled the fertility of B06S.

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Rice Blast Resistance and Peroxidase Activity of Rice Transformed with PAL Gene LI Jun ying,GUO Ze-jian,ZHANG Bing-xin 2004, 18(4): 303-308 .  Abstract ( )   PDF (263KB) ( )   By sense and antisense transformation with PAL(phenylalanine ammonia lyase) gene, 70 transgenic rice plant lines were got. When the sense transformant (line 1s) and the antisense one (line 4a) were inoculated with Magnaporthe grisea, the PAL activity in line 1s increased earlier and much more than that in line 4a. The observation on ultrastructure of rice leaf cells showed that the cells of line 1s had stronger resistance to the pathogen invading and higher activity of peroxidase than those of the untransformed and line 4a.

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Evaluation of Allelopathic Potential of Some Chinese Rice Against Weeds LI Di ,ZHOU Yong-jun ,LIU Xiao chuan ,YU Liu-qing*,TANG Fu-bin ,WEI Xing hua ,GUO Long-biao 2004, 18(4): 309-314 .  Abstract ( )   PDF (254KB) ( )   Experiments were conducted in the plant growth chamber and paddy field respectively. Two rice varieties (Oryza sativa L.) with allelopathic property against a barnyardgrass [Echinochloa crusgalli (L.) Beauv. var. mitis (Pursh) Peterm] were obtained after evaluating more than 470 rice accessions of rice germplasm provided by China National Rice Research Institute. One is I-Kung-Pao, a Taiwan native variety, with its RRL (relative factor of the barnyardgrass root length) 0 43. The leaves water extract of I-Kung-Pao inhibited barnyardgrass root length by 45% and lettuce root length by 85% , respectively. In paddy field I Kung Pao showed inhibitory effect on the barnyardgrass plant density by 22.0% and reduced the plant fresh weight by 26.1%. The other is D-gu, a variety from Yunnan, with its RSH (relative factor of the barnyardgrass plant height) 0.62 and RPDW (relative factor of the barnyardgrass plant dry weight) 0.58. The root length control effects were 53% for the barnyardgrass and 65% for the lettuce after treated with D-gu leaves water extract. In paddy field D gu markedly controlled the barnyardgrass plant density by 51.5% and the plant fresh weight by 46.1%. The lettuce root length control effect resulted from I Kung Pao and the barnyardgrass control effect from D gu were significantly greater than those from American allelopathic rice PI312777. I Kung Pao and D gu are valuable rice germplasm with allelopathic potential in China.

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Analysis on Variation and Difference for Rice Quality Traits among Different Types of Rice ZHU Zhi wei,CHEN Neng,WANG Dan-ying,ZHANG Xiu-fu,YAO Qing,MIN Jie,LIAO Xi-yuan* 2004, 18(4): 315-320 .  Abstract ( )   PDF (227KB) ( )   Based on total 8 390 rice samples of indica conventional rice, indica hybrid rice, japonica conventional rice, japonica hybrid rice, the differences of the quality traits among different rice types were analyzed. The main results were as follows: (1) Variation coefficients of quality traits in conventional rice varieties were slightly higher than those of hybrid rice. Variation coefficients of grain chalkiness, translucency and chalkiness were high, but those of brown rice rate, milled rice rate and head rice rate were low. (2)Quality of japonica rice was higher than that of indica. Chalkiness, head rice rate and amylose content should be emphasized in indica rice quality improvement. Reducing chalky grain and increasing head rice rate were important in japonica rice quality improvement. (3) The quality of indica hybrid rice was improved significantly. Except chalkiness, frequency of the other quality characteristics meeting the high quality standards was high. (4) In indica conventional rice, the frequency of chalkiness and amylose content appeared two apex distribution, both high quality and low quality indica conventional rice rate were high.

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Difference in Amylose Content Variation of Rice Grains and Its Position Distribution Within a Panicle Between Two Panicle Types of Japonica Cultivars ZHU Hai-jiang,CHENG Fang-min *,WANG Feng,ZHONG Lian-jin,ZHAO Ning-chun,LIU Zheng-hui 2004, 18(4): 321-325 .  Abstract ( )   PDF (214KB) ( )   Under the field conditions, six japonica cultivars with erect panicle and four japonica cultivars with curved panicle were applied to compare the difference in the amylose content (AC) of rice grains and its position distribution in a panicle. Results indicated that the panicle type had a considerable influence on the AC variation of rice grains within a panicle. The cultivars with erect panicle generally had higher variation coefficient, larger dispersing degree and wider variation range of AC than the cultivars with curved panicle, despite it was not significantly related to the AC of cultivar; The AC variation of rice grains within a panicle was closely related to the position of rice grains on the rachis branches, the grains with the relatively low AC often appeared at the bottom or in the middle of the panicle while the grains with the relatively high AC was generally at the top of the panicle. However, more grains with low AC, distributed in the middle of the panicle, could be observed in the cultivars with erect panicle than in the cultivars with curved panicle.

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Promotive Effect of Exogenous C4-Bicarboxylate on Photosynthetic C4 Pathway in Transgenic Rice Plant Expressing Maize Specific PEPC Gene ZHU Su-qin ,JI Ben-hua ,JIAO De-mao 2004, 18(4): 326-332 .  Abstract ( )   PDF (279KB) ( )   Photosynthetic C4 microcycle and its function in different genotype rices were explored comparatively using PEPC transgenic rice (PC) and homozygous wild genotype rice (WT) Kitaake as experimental materials. In WT rice, there existed an intact C 4 photosynthetic enzyme system which were verified through detecting photosynthetic C4 pathway related key enzymes, i.e. phosphoenol pyruvate carboxylase (PEPC), NADP malic enzyme (NADP ME), NADP malate dehydrogenase (NADP MDH) and pyruvate, orthophosphate dikinase (PPDK), and a primitively limited photosynthetic C 4 microcycle pathway through assaying increased photosynthetic rate in leaf discs or chloroplasts fed with exogenous oxaloacetate (OAA) or malate (MA). Furthermore, photosynthetic C 4 microcycle was promoted in a great range in PC rice. Enhancement of photosynthetic C4 microcycle further played some role in raising the net photosynthetic rates (Pn) and debasing the ratio of photorespiratory rate and net photosynthetic rate( Pr/Pn ), which were comfirmed through determining the CO2 gas exchange rate in different genotype rices, WT or PC. Analyzing the chlorophyll fluorescence characteristics showed that enhancement of photosynthetic C4 microcycle companied with the raising PSⅡelectron transport efficiency (Fv /Fm ) and photochemical quenching (q p ), and the lowering of non photochemical quenching (q N ). These results will provide scientific evidence for genetic breeding to improve photosynthetic efficiency in crops by gene engineering.

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Effect of Water Management on Photosynthetic Rate and Water Use Efficiency of Leaves in Paddy Rice LIN Xian-qing,ZHOU Wei-jun,ZHU De-feng,ZHANG Yu-ping 2004, 18(4): 333-338 .  Abstract ( )   PDF (239KB) ( )   Photosynthetic rate and water use efficiency of rice leaves at the stages of panicle initiation, flowering and 20 days after flowering were determined under three different water managements with two super hybrid rice combinations of Liangyoupeijiu and Zhongyou 6. Different water managements had an important effect on above ground dry weight, leaf area index, leaf photosynthetic rate, leaf transpiration rate and water use efficiency. The above ground dry weight and water use efficiency were increased under the conditions of aerobic irrigation. Leaf transpiration rate, above ground dry weight and water use efficiency were all decreased under the conditions of low water level. Above ground dry weight, leaf area index, leaf photosynthetic rate, leaf transpiration rate and water use efficiency under the conditions of submerged were less than those under the conditions of aerobic irrigation. Water managements had no significant effect on protein content of rice grain.

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A Knowledge Model for Design of Suitable Phosphorus and Potassium Fertilization in Rice YAN Ding-chun,ZHU Yan,CAO Wei-xing 2004, 18(4): 339-345 .  Abstract ( )   PDF (285KB) ( )   Based on summarizing dynamic relationships between phosphorus and potassium fertilization and variety type, ecological factors and farming conditions from studying the literature and consulting experts, a rice knowledge model for design of suitable phosphorus and potassium fertilization under varied environments was developed through knowledge engineering and system modeling methods. The model can quantify the suitable total rates of phosphorus and potassium, ratios of basal to top dressing phosphorus and potassium under different environments and production systems. Case studies on the model with the data sets of typical varieties, soil fertility levels, farming systems and field comparative experiments indicated a good performance of the model system in applicability and decision making.

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Genetic Structure of Magnaporthe grisea in the Fields of Different Rice Varieties in Yunnan Japonica Rice Planted Area ZHANG Zhong-quan,HE Xia-hong,WANG Yun-yue,YANG Jing,ZHOU Jiang-hong,LI Zuo-sen,ZHU You-yong-* 2004, 18(4): 346-350 .  Abstract ( )   PDF (219KB) ( )   The DNA of 242 Magnaporthe grisea isolates from Mile County, Yunnan Province, which originated from monoculture and mixture fields, was extracted and amplified by rep PCR which primers were from palindromes Pot2 of Magnaporthe grisea. All isolates were amplified 2-28 DNA bands, the size was from 400 bp to 23 kb, but mainly from 5-10 kb and 80% bands were in 0.4-6.0 kb. Genetic structure of Magnaporthe grisea in different culture pattern fields by clustering analysis showed that there was relationship between complexity of isolates genetic lineages and culture patterns. There were more genetic lineages in mixture field than in monoculture one. The dominant lineages were not distinct in mixture field. In 80% similarity, the strains from glutinous rice in monoculture were divided into nine lineages, while strains from japonica in mixture were 15 lineages. The result proved that biodiversity might provide a convincing basis for the steady selection of rice variety to pathogen.

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Distribution of Magnaporthe grisea Populations and Virulence of Predominant Races in Jiangsu Province LIU Yong-feng ,CHEN Zhi-yi ,HU Ming ,LI Lian ,LIU You-zhou 2004, 18(4): 351-356 .  Abstract ( )   PDF (196KB) ( )   Three hundred and forty two monoconidial isolates were obtained from rice blast specimens collected from five typical areas in Jiangsu Province during 2000-2002. The isolates could be classified into seven groups, thirty races when they were assessed with seven Chinese differential rice cultivars. The race ZG1 was predominant one with a frequency of 65.00% in 2000, 56.90% in 2001 and 60.38% in 2002; the races ZB and ZC groups were important ones in Jiangsu Province. By inoculating 130 ZG1 race isolates on 13 Japanese cultivars with known resistance genes, 42 pathotypes were found, 30.77% of ZG1 race isolates which was predominant pathotype were virulent to the Shin 2(Pita-ks,Pi-sh) ,K1(Pi-ta), Pi 4(Pi-ta2,Pi-sh), suggesting that the resistances of Shin 2(Pita-ks,Pi-sh),K1(Pi-ta), Pi 4(Pi-ta2,Pi-sh) had lost in Jiangsu Province. K3(Pi-kh) was highly resistant to Magnaporthe grisea in Jiangsu Province with 100% of resistance frequency. When two isolates, 2003 184(ZC5) and 2003-14-1(ZG1), with different virulences were mixed to inoculate, K3 (Pi-kh) which has resistance to the two isolates respectively was infected by the mixed isolates. It indicated the change of virulence resulted from the interaction among different pathotype isolates was one of the reasons that made variety lose its resistance.

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Screening of Temperature Sensitive Mutants in Magnaporthe grisea WANG Hong-kai ,LIN Fu-cheng ,CHAI Rong-yao ,LI De-bao 2004, 18(4): 357-361 .  Abstract ( )   PDF (219KB) ( )   Temperature sensitive mutants(ts mutants) are good material for studying cell division and differentiation. Two hundred and seventy four ts mutants of Magnaporthe grisea were induced by UV radiation. These mutants could grow at 25℃, but not at 33℃. Pathogenicity test indicated that the pathogenicity of 32 ts mutants reduced distinctly. Under 33℃ conditions, seven of them did not germinate, 12 stopped growing after germination and no appressorium formed, nine stopped growing after appressorium formed, four mutants formed swell and bunch appressorium, then stopped growing. The ability of perithecia formation of some mutants was changed.

实验技术

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Determination of Cytokinins in Rice Root Exudates by High Performance Liquid Chromatography(HPLC) SHEN Bo ,PING Xiao-fei ,TANG Fu-bing ,YAN Hong-lan ,WANG Xi 2004, 18(4): 362-364 .  Abstract ( )   PDF (127KB) ( )   A high performance liquid chromatographic method had been established to determine cytokinin contents of root exudates in rice. This method was simple, reliable and accurate, and could be used for measuring zeatin, dihydrozeatin, dihydrozeatin riboside, and N6 isopentenyladenine in rice root exudates.

综述与专论

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Historical Review on the Genomic Denomination of the Genus Oryza L. FENG Jiu-huan,ZHAO Xing-juan,LU Yong-gen * 2004, 18(4): 365-370 .  Abstract ( )   PDF (226KB) ( )   The genus Oryza L. including 25 species fell into 10 recognized genome types, i.e. AA, BB, CC, BBCC, CCDD, EE, FF, GG, HHJJ and HHKK, respectively. As early as in 1930s, Morinaga and his co workers firstly studied and assigned the genomes to some Oryza species. The conventional approaches used by Morinaga for assigning new genomes were mainly based on morphological and physiological differences, especially chromosome pairing behavior of F1 hybrids between two species. Since then, genome constitutions of other Oryza species were supplemented by different investigators. However, if the interspecific hybrids are difficult to produce due to strong hybridization barriers, it is impossible to assign genomes to species by above conventional approaches. Recently, by using molecular biological technique, e.g., molecular marker analysis and fluorescent in situ hybridization(FISH), some workers assigned three new genomes to the species which were difficult to obtained hybrids with other Oryza species. Because these works were done in early days (during 1940s-1960s) by many investigators, it is essential to summarize the process and principle for assigning genome symbols so as to easily understand the meanings of all genome symbols.

研究简报

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Antifeedant Activity of the Extracts of Six Species of Wild Rice Aganist Spodoptera litura FENG Guo-zhong ,WAN Shu-qing ,PAN Da-jian ,LUO Qian ,DENG Jian-chao 2004, 18(4): 371-373 .  Abstract ( )   PDF (131KB) ( )   Six species of wild rice E6-1, E6-3/6-4 (different ecotypes of Oryza grandiglumis), E7-4(O. granulata), E9-10, E9-20(different ecotypes of O. latifolia),E13-13(O. minuta), E15-13 (O. officinalis) and E16-3(O. punctata) were extracted with methnol by Sohxlet method. The extract rates of the six species of wild rice were 19.62%,15.60%,18.90%,8.50%,16.27%, 24.86%,10.04% and 13.32%, respectively. Selective antifeedant activity and non-selective antifeedant activity of extract from the six species of wild rice against the 3rd instar larvae of Spodoptera litura showed that the extract of the wild rice E6-1 was better than the others.When the concentration was 1%, selective antifeedant activity of the E6-1 extracts was 100% in 24 h and 48 h and non selective antifeedant activity was 40 95% and 47 27% in 24 h and 48 h after treatment, respectively.The concentration of 50% antifeedant of the wild rice E6 1 extract against 2nd instar larvae of Spodoptera litura was 120 mg/mL in 24 h and 50 mg/mL in 48 h after treatment.

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Difference of Nucleic Acid and Protein Metabolism in Superior and Inferior Grains of Rice HUANG Sheng-mou ,ZOU Ying-bin 2004, 18(4): 374-376 .  Abstract ( )   PDF (168KB) ( )   By using two line hybrid rice Liangyoupeijiu and Peiliangyou 500, the RNA and protein contents in ovaries of superior and inferior grains were analyzed. At heading, total RNA contents per unit weight in superior grain ovaries were higher than those in inferior grain ovaries, and protein content contrarily. At the fifth day after heading, total RNA contents per unit weight in superior grains ovaries were still higher, the difference of the mRNA was not significant, protein contents per unit weight were lower compared with those in inferior grain ovaries. Either superior grains or inferior grains, the contents of total RNA, mRNA and protein in a single grain increased from heading to the fifth day after heading, and the contents in superior grains were higher than those in inferior grains at every stage. Two protein bands were found in superior grains but none in inferior grains at heading, and only one in inferior grains at the fifth day after heading. It suggested that the gene related to grains filling in superior grains expressed earlier and more briskly than that in inferior grains.