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10 May 2005, Volume 19 Issue 3 Previous Issue    Next Issue
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研究报告
综述与专论
实验技术
研究简报


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研究报告

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Screening SSR Markers for Rice Variety Identification SHI Yong-feng ,YING Jie-zheng ,WANG Lei ,ZHU Zhi-Wei ,ZHUANG Jie-yun 2005, 19(3): 195-201 .  Abstract ( )   PDF (387KB) ( )   A total of 58 DNA simple sequence repeat (SSR) markers were selected to detect polymorphisms among 28 parental lines of commercial F 1 hybrid rice used in China. Fourteen of the markers were assayed by using both agarose gel electrophoresis and non-denaturing polyacrylamide gel electrophosresis (PAGE). It was shown that each of the rice lines can be unambiguous distinguished, and great variations on the frequency of polymorphism were observed among the markers used. Similar results were generated by agarose gel electrophoresis and non-denaturing PAGE, while the non-denaturing PAGE had higher resolution, showing feasibility for its application in the variety identification of rice. On average, the probability of distinguishing the rice lines by detection with 12 SSR markers was higher than 99.9%, but markers of higher variation and/or more markers may be required for varieties having high genetic similarity.

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Homologues of Nodulin Genes in Oryza sativa WANG Yan-zhang ,YU Guan-qiao ,ZHU Jia-bi 2005, 19(3): 202-208 .  Abstract ( )   PDF (228KB) ( )   Seventy-five nodulin genes, found in nucleotide databases, were used as probes to scan the rice genome by bioinformatics methods. Thirty-one homologues of nodulin genes were detected in the rice genome which exhibited more than 35% identities in amino acid sequences in comparison with leguminous nodulin genes. This result indicated that leguminous nodulin homologous genes existed extensively in rice genome. In comparison with the leguminous nodulin gene enod40, sucrose synthase gene and Rab gene, their corresponding homologues in rice showed that they all belonged to the classification of orthologous genes, presumably originated from the common ancestral genes. However, leguminous nodulin genes mutated during the early evolution so as to meet the requirements of nodule organogenesis. The other 44 leguminous nodulin genes, which have no homologs in rice genome, play essential roles in establishing symbiosis between the Rhizobium and the host legumes. It was suggested that the lack of these leguminous nodulin genes in rice might result in its disablility for nodulation and nitrogen fixation.

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Relationship Between Phenotype of Blast Resistance and Similarity of Resistance Gene (Analog) in Rice Varieties LIU Er-ming ,XIAO Yi-long ,YI You-jin ,ZHUANG Jie-yun ,ZHENG Kang-le ,LUO Feng 2005, 19(3): 209-216 .  Abstract ( )   PDF (289KB) ( )   Six pairs of primers, viz. RGA1(Resistance gene analog) (XLRR-for/ XLRR-rev), RGA2 (XLRR-inv1/XLRR-inv2), RGA3(NLRR-for/NLRR-rev), RGA4 (NLRR-inv1/NLRR-inv2), RGA5 (Pto-kin1/Pto-kin2) and RGA6 (Pto-kin3/Pto-kin4), were used to fingerprint 21 rice varieties based on RGA-PCR. Clustering analysis showed that the 21 varieties could be both classified into 5 groups at 0.72 similarity coefficient or using index of leaf blast severity at 0.84 level. Although there is no parallelism relationship between group and group in two different types of the clustering, the varieties, such as Xiangzi 3150, IR156, Zhuliangyou 02 and ZR02 with broad spectrum or durable resistance can be finely fallen into the same group. It was also suggested that 3 pairs among 6 primer pairs, viz. RGA1 and RGA2 designed from the LRR region of rice Xa21 gene and RGA3 from the LRR region of tobacco N gene, were more suitable to evaluate rice germplasms for their genetic responses to rice blast by RGA-PCR.

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Mapping Cold Tolerance Gene by Near-Isogenic Lines at Booting Stage in japonica Rice SHEN Shi-quan ,ZENG Ya-wen ,LI Shen-chong ,WEN Guo-song ,PU Xiao-ying 2005, 19(3): 217-222 .  Abstract ( )   PDF (195KB) ( )   Genetic analysis showed that cold tolerance at the booting stage in near-isogenic line(NIL) of Kunmingxiaobaigu was controlled by gene with large phenotypic variance. One hundred and sixty-four simple sequence repeat(SSR) markers on 12 chromosomes were used to detect polymorphism between Towata (RP) and near-isogenic line pool(NILP). Two SSR markers at terminal of long arm of chromosome 5 had polymorphism in comparison with RP genome. RM31 of them was found possibly linked with the cold tolerance gene at the booting stage through one-way ANOVA, then 12 SSR markers around RM31 were used for further detection of polymorphisms between RP and NIL, and RM7452 had polymorphism. The locus of cold tolerance gene at the booting stage was mapped on chromosome 5 between RM7452 and RM31 with a genetic distance of 4.8 cM and 8.0 cM, respectively, which explained 10.50% of phenotypic variance and 5.10% of phenotypic variance of full filled grains. This gene was tentatively designated as Ctb(t).

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Genetic Analysis on Panicle Angle and Number of Spikelets per Panicle in japonica Rice (Oryza sativa) LIU Jin-bo ,HONG De-lin 2005, 19(3): 223-230 .  Abstract ( )   PDF (226KB) ( )   Phenotypic distributions of panicle angle and number of spikelets per panicle were investigated in P1, P2, F1 and F2 generations(in 2002) and P1, P2, F1, F2, F2∶3 generations(in 2003) from the cross Bing 8979(erect panicle, japonica rice) and C Bao(curved panicle, japonica rice). Genetic analyses for the two traits were conducted by using major gene-polygene mixed inheritance models and joint analysis method of segregating plus non-segregating generations. Both panicle angle and number of spikelets per panicle were controlled by two major genes+polygenes. Both the independent two major genes and polygenes had additive-dominance-epistatic effects.Panicle angle was mainly governed by major gene, while number of spikelets per panicle was by polygenes.

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Some Factors Affecting Agrobacterium-Mediated Transformation Frequency in Rice LI Shuang-cheng ,WANG Shi-quan ,YIN Fu-qiang ,ZOU Liang-ping ,QI Deng-feng ,JIANG Hong ,LI Ping 2005, 19(3): 231-237 .  Abstract ( )   PDF (408KB) ( )   Several important factors affecting rice transformation mediated by Agrobacterium were investigated with three indica and two japonica rice varieties. Co-transformation with Agrobacterium strains AGL1 and EHA 105, and by re-suspending the strains with NB culture media before transformation could improve the resistant calli rate significantly. Because of distinct influence on both the resistant calli rate and the differentiation rate, doubling the agar powder and being blew on the worktable for 4 h were considered as suitable approaches for desiccation culture. Adding DMSO or proline into the differentiation media, and NAA to the rooting media could, to some extent, improve the regeneration rate and the surviving rate, respectively. Many useful transgenic plants identified by PCR and Dot-blotting were obtained by using this protocol.

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Effect of Ridge Cultivation on Root Growth of Rice in Cold Region QIAN Yong-de ,LI Jin-feng ,ZHENG Gui-ping ,LU Yan-dong ,GUO Xiao-hong ,SUN Chang-yan 2005, 19(3): 238-242 .  Abstract ( )   PDF (172KB) ( )   A high yielding and superior quality japonica rice variety Kongyu 131 was employed to study root growth characteristics in cold region under ridge cultivation and conventional cultivation. There were significant differences in root growth and distribution under different cultivation methods. Root length, dry weight, number of roots (especially number of roots in deep soil layers), and root absorption area, root/shoot ratio and grain yield under ridge cultivation were increased in comparison with those under conventional cultivation.

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Source-Sink Characteristics of Main Crop and Ratooning Rice of Several New Hybrid Rice Combinations YI Zhen-Xie ,TU Nai-mei ,CHEN Ping-ping 2005, 19(3): 243-248 .  Abstract ( )   PDF (190KB) ( )   Eight hybrid rice combinations were used to study the source-sink characteristics of main crop and ratooning rice in hybrid rice, and the source-sink relationship for yield formation in ratooning rice. The results indicated that:(1) Leaf area index(LAI) of ratooning rice was about one third of that of the main crop, and leaf area per culm of ratooning rice was about from one seventh to one third of that of the main crop. The whole sink volume of the main crop was about 1.5 times of that of ratooning rice. The ratio of grain number to leaf area in ratooning rice was 1.5 to 2 times of that in the main crop. (2) High ratio of grain number to leaf area was beneficial to get high yield in the main crop. High LAI at maturity stage, low ratio of grain number to leaf area, high weight of stem-sheath at maturity stage and high export percentage of the matter in stem-sheath in the main crop were helpful to obtain high yield in ratooning rice. (3)There was a positive correlation at the 0.05 level between LAI at full heading stage and yield of ratooning rice. To upper-node ratooning rice, there were a positive correlation at the 0.01 level between leaf area per culm at full heading stage and yield per culm, a negative correlation between the ratio of grain number to leaf area and seed setting rate, and a negative correlation at the 0.01 level between the ratio of grain number to leaf area and yield. The type of source-sink relationship of ratooning rice, especially of upper-node ratooning rice belonged to the source-limited. (4)The yields of ratooning rice of Lu 18S/53159, Kangliangyou 2054, Pei′ai 64S/E32 and Peiliangyou 500 were all above 5200 kg/hm2. Considering synthetically yield of ratooning rice and the total of the two crops, under the climate conditions of 2002 in Changsha region, the optimal combination for ratooning was Pei′ai 64S/E32, followed by Kangliangyou 2054 and T98A/259.

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Response of Flag Leaves of Super High-Yielding Rice Pei′ai 64S/E32 and Liangyoupeijiu to High Temperature OU Zhi-Ying ,LIN Gui-Zhu ,PENG Chang-lian 2005, 19(3): 249-254 .  Abstract ( )   PDF (226KB) ( )   Two newly bred hybrid rice combinations, super high-yielding rice Liangyoupeijiu (Pei′ai 64S×9311) and Pei′ai 64S/E32 were used to investigate the photosynthetic characteristics at high temperature in comparison with hybrid rice (Shanyou) 63. High temperature caused a decreasing photosynthetic efficiency and aggravated photoinhibition. The optimum temperatures of photosynthetic electron transportation and photosynthetic CO2 fixation were about 28℃ and 35-40℃, respectively. Linear electron transportation was more sensitive to high temperature than the photochemical process. The mechanism of high temperature adaptation in super high yielding rice might involve that carotenoid increase more quickly in super high-yielding rice and act as a better antioxidant system to reduce the active oxygen production and avoid the photosynthesis machinery hurting, and super hybrid rice has a higher efficiency of xanthophylls cycle to dissipate excess excitation energy, and has a more stable photosynthetic function, higher photosynthetic efficiency and more heat stable protein content.

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Regulation of Senescence and Photosynthetic Function of Rice Leaves by Controlled Release Nitrogen Fertilizer NIE Jun ,ZHENG Sheng-xian ,DAI Ping-an ,XIAO Jian ,YI Guo-ying 2005, 19(3): 255-261 .  Abstract ( )   PDF (253KB) ( )   The physiological traits of senescence and photosynthetic function of rice leaves were analyzed when two hybrid rice combinations were supplied with controlled release nitrogen fertilizer (CRNF), urea and no nitrogen fertilizer. CRNF showed obvious effects on delaying the senescence and prolonging the photosynthetic function duration of rice leaves. Compared with urea, CRNF could significantly increase the chlorophyll contents of the functional leaves at different stages in both early and late rices, and the difference between the treatments became larger with rice development. Photosynthetic rates of the functional leaves at different stages in CRNF treatment were significantly higher than those in urea treatment. Moreover, compared with urea, CRNF increased the activities of active oxygen scavenging enzymes, such as SOD and POD, and decreased the accumulation amount of MDA in the functional leaves during rice leaf aging. IAA and ABA contents in the functional leaves were also obviously regulated by CRNF. At the every stage, IAA content in CRNF treatment was higher and ABA content was lower than those in urea treatment. Being attributed to the effects of CRNF mentioned above, the rice yield was obviously increased after CRNF application.

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Effects of Soil Cu Concentration on Growth and Development and Yield Formation of Rice XU Jia-kuan ,YANG Lian-Xin ,WANG Zhi-qiang ,DONG Gui-Chun ,HUANG Jian-Ye ,WANG Yu-long 2005, 19(3): 262-268 .  Abstract ( )   PDF (243KB) ( )   Pot experiments were conducted in 2002-2003 using japonica variety Wuxiangjing 14 and hybrid rice Shanyou 63 as materials. Effects of lower soil Cu concentrations (100, 200 mg/kg) were light on rice height, leaf number of the main stem, elongated internode number and heading date. However, when soil Cu concentration reached 400 mg/kg,rice growth was inhibited seriously, and the degrees of damage on rice growth were enlarged with the increment of soil Cu concentration. With the increase of soil Cu concentration,the yield loss became significant. Which were attributed to the reduction of spikelet numbers per panicle under lower soil Cu concentration (100, 200mg/kg), and the decreases of panicle numbers and spikelet numbers per panicle under higher soil Cu concentration (400 mg/kg and above). The decreases of panicle numbers at higher soil Cu concentrations were mainly related to delay in reviving and establishment of plant,lower initial tillering velocity and maximum tiller numbers. The decrease of spikelet numbers per panicle at higher soil Cu concentrations was chiefly caused by the drop of dry matter weight per stem and spikelet surviving ability (the ratio of survived spikelet number per panicle to the dry matter weight per stem) at heading stage. Total biomass fell significantly with the increase of soil Cu concentration, while no significant decrease of economic coefficients were detected except at very higher soil Cu concentrations (800 mg/kg and above).

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Effects of Pb Pollution on Seed Vigour of Three Rice Varieties CHEN Zhen-hua ,ZHANG Sheng ,Hu Jin ,CHEN Jian-feng ,ZHENG Yun-ye 2005, 19(3): 269-272 .  Abstract ( )   PDF (148KB) ( )   Seed germination and seedling development at different Pb concentrations in three rice varieties (Jiayu 293, (Jiayu) 948 and Xieyou 963) were investigted. The method of qualitative trait combining with quantitative trait by orthogonal polynomials was applied to analyze rice seed vigour by regression model. Seeds from different rice varieties showed different sensitivities to Pb poison. In the Pb concentration of 100-700 mg/L, Pb had significant inhibitory effects on root length and shoot height, and the restraint would aggravate along with the increase of Pb concentration. However, Pb had no inhibitory effect on root dry weight and shoot dry weight, indicating that different physiological characteristics had different sensitive reactions to Pb. The gained predicting equation of regression could predict the effects on rice seed vigour at different Pb concentrations.

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Effect of Grain Position in a Panicle and Varieties on As,Cd,Cr,Ni,Pb Contents in Grains of Late japonica Rice CHENG Wang-da ,ZHANG Guo-ping ,YAO Hai-gen ,Peter Dominy ,WANG Run-yi 2005, 19(3): 273-279 .  Abstract ( )   PDF (248KB) ( )   Two japonica rice varieties, a compact panicle type variety (CP) Xiushui 63 and a loose panicle type variety (LP) Xiushui 11, were grown in a slightly contaminated paddy field to determine the effect of grain position within a panicle and varieties on toxic heavy metal content in rice grains. There was a significant variation in heavy metal content among grains within a panicle. Furthermore, this variation varied with variety and metal. Shch as, Xiushui 63 showed higher variation than Xiushui 11, and As, Cd, Cr and Pb had a significant variation, while no significant variation for Ni. The top grains (TG) in a panicle had higher As, Cd and Ni contents compared with the middle ones (MG), and the bottom grains (BG) had the lowest. With regard to Cr and Pb, the case was opposite. The significantly positive correlations were found between grain weight and As, Cd, Ni contents in grains, but negative for grain weight and Cr, and Pb content. There was a remarkable difference in grain filling pattern among grains within a panicle, and between Xiushui 63 and Xiushui 11. In comparison with middle grains and top grains in a panicle, the bottom ones had lower grain filling rate and grain weight, leading to obvious difference in grain weight among grains within a panicle, and Xiushui 63 had significantly larger difference than Xiushui 11. There were significant and positive correlations between As, Cd, Ni content in grains and the maximum grain filling rate, but negative between the contents of these elements in grains and the time reaching the maximum grain filling rate. Concerning Cr and Pb, the case was just opposite. It is suggested that the accumulation of As, Cd and Ni is accompanied by accumulation of carbohydrates in rice grains.

综述与专论

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Conception of Late-Stage Vigor Super Hybrid Rice and Its Biological Significance CHENG Shi-hua ,CAO Li-yong ,CHEN Shen-guang ,ZHU De-feng ,WANG Xi ,MIN Shao-kai ,ZHAI Hu-qu 2005, 19(3): 280-284 .  Abstract ( )   PDF (233KB) ( )   China initiated its research program of super rice breeding in 1996, in reference of new plant type rice breeding program of IRRI. The super hybrid rice was depicted as the combination of ideo-plant type and strong subspecies heterosis,and the targeted grain yield for single season cropping in 2005 is 12 t/hm2 under the scale of 6.67 hm2. The status of super hybrid rice breeding program in China and high-yielding rice breeding program in other countries were introduced. Xieyou 9308, a super hybrid developed by China National Rice Research Institute(CNRRI), showed high-yielding potential in combination with ideo-plant type and vigorous leaf and root in late growth period. It yielded the record of 11 837 kg/hm2under 6 67 hm2and (12 282) kg/hm2in small plot at Xinchang, Zhejiang in 2000. Based on its performance, the conception of late-stage vigor super hybrid rice and its biological significance are formulated. Meanwhile, the further breeding strategy for super hybrid rice is discussed.

实验技术

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One-Step PCR Method for Detecting the First Base of Splice Donor of Wx Intron 1 in Rice MAO Xing-xue ,XIAO Xin ,CHEN Jian-wei ,LUO Wen-yong ,LIU Yan-zhuo ,LI Xiao-fang 2005, 19(3): 285-287 .  Abstract ( )   PDF (146KB) ( )   A new method to detect the first base of splice donor of Wx intron 1 in rice was reported, and some indica rice samples from Guangdong Province were analyzed using this method. The results showed that this new method is credible, easier and cheaper than the usual PCR-Acc Ⅰ method. It meets the requirement for amylose content selection in rice breeding.

研究简报

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Study on Asexual Recombination in Magnaporthe grisea by Using Nitrate Non-Utilizing (nit) Mutants and Fungicide-Resistance as Independent Genetic Markers ZHANG Chuan-qing ,ZHOU Ming-guo 2005, 19(3): 288-290 .  Abstract ( )   PDF (119KB) ( )   Genetics of kitazin P resistance in asexual recombination of Magnaporthe griseawas studied by using nitrate non-utilizing (nit) mutants. Asexual recombinants were detected in all the three pairings, namely DY2-3(nit1-LR)×A7-3(nitM-S),A7-3(nitM-S)×F4-2(nit1-MR), and F4-2(nit1-MR)×DY2-4(nitA-LR). The frequencies of the asexual recombinations were 7.31%, 14.00% and 8.63%, respectively. Most of recombinants had satisfied growth, spore production and pathogenicity ability, indicating that asexual recombinants had high fitness. These results suggested that asexual recombination caused by hyphal fusion might play an important role in the development of fungicide resistant population in M. grisea.