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10 January 1995, Volume 9 Issue 1 Previous Issue    Next Issue
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研究报告
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研究报告

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A Primary Study of Cultivated Rice(Oryza sativa)and Common Chinese Wild Rice(O. rufipogon)Using Random Amplified Polymorphic DNA(RAPD) Sun Chuanqing,Mao Long,Wang Zhenshan,Zhu Lihuang,Wang Xiangkun 1995, 9(1): 1-6 .  Abstract ( )   PDF (671KB) ( )   Ten cultivated rice varieties(O. sativa) and 27 accessions of Chinese common wild rice(O. rufipogon)were analyzed by RAPD using 35 primers. The results indicated that almost 60% of used primers could reveal polymorphisms between indica and japonica varieties. The difference of O. rufipogon to O. sativa disptayed mainly between the wild rice and O. sativa ssp. indica. It suggested that most accessions of wild rice have the similar RAPD patterns to that of O. sativa ssp. japonica. This indicated that most Chinese common wild rice is similar to japonica type, and also some Chinese common wild rice is similar to indica type.

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Preliminary Analysis of the Population Structure of Xanthomonas oryzae pv. oryzae in China Zhang Qi,Wang Chunlian,Jan E. Leach,R J Nelson,T W Mew 1995, 9(1): 7-14 .  Abstract ( )   PDF (264KB) ( )   Seventy eight strains of Xanthomonas oryzae pv. oryzae collected mostly from North, Northeast and a few from Center and South China have been assessed the RFLP types for analyzing the population structure and genetic diversity by using two probes, pJEL 101 and pBSavrXa 10. Genomic DNA from each strain of X. o. pv. oryzae was digested to completion by enzymes EcoR I or BamH I for blots probed with pJEL101 or pBSavrXa10. Sixteen RFLP types were identified respectively. Fourteen RFLP types were found in strains of pathotypes 1, 2 and 6, which were from North and Northeast China(using pJEL 101).Among them differed only at one or 3-4 banding positions. In comparison between those with RFLP types of strains from Guangdong and Yunnan provinces were distinct from one another at 7 or 8 positions varied. Cluster analysis based on RFLP banding showed six groupings at 85% similarity. The majority of strains from pathotypes 1, 2 and 6 were grouped in clusters 1. A few strains, LN43, GD1358 and YN5 were grouped in clusters 4, 5 and 6. respectively. The genetic diversities of the population of strains tested was 0.77 (for pJEL101 ) and 0.83 (for pBSavrXa10) respectively. Genetic diversities for each pathotypes tested as a subpopulation has been also calculated. The preliminary analysis here showed that the genetic diversity of X.o. pv. oryzae in China was various. It will be necessary to assess more strains collected from South, Center and Southwest China for analyzing the population constructure and genetic relationship of X.o. pv. oryzae in China systematically.

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Improving Transformation Efficiency of Pyricularia oryzae Huang Danian,Wang Jinxia,Yang Wei,Ni Yunmei 1995, 9(1): 15-20 .  Abstract ( )   PDF (661KB) ( )   The transformation system of rice blast fungus(Pyricularia oryzae) with hygromycin B as selective marker had been established in our laboratory. In order to improve transformation efficiency the effective conditions were studied. The transformation efficiency of using 40% PEG4000(or 40% PEG8000) were greater than that of 20% PEG4000(or 20% PEG8000). The best suitable CaCl2 concentration was 50-100 mmol/L in transformation. Adding 5-30 μg herring sperm DNA can improve transformation efficiency obviously and the herring sperm DNA may be one of indispendable condition of the transformation. Our result indicated that receipt strain DNA had negative influence on transformation, and 42℃ heat shock for 2 or 8 minutes had not active effect. Transformation with linear DNA was better than circular DNA, which conformed to the results of literature.

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Genetic Analysis of Heading Time Transgression of F1 between Lunhui 422 and Indica Varieties Gu Xingyou,Gu Minghong 1995, 9(1): 21-26 .  Abstract ( )   PDF (366KB) ( )   In remote crosses of indica and japonica rice varieties, maturation period transgression is a common phenomenon. In order to understand the genetic mechanism governing the phenomenon, the heading time of F1 to F3 and BC1 generations under long day and short day conditions were inspected in crosses between Lunhui 422(a japonica-cline wide compatibility varieties) and two indica varieties Nanjing 11 and 188025 (with a genetic marker cluster spikelet controlled by Cl gene in chromosome 6). Under the long day, the heading time of F1s was very late and their transgressive heterosis was over 49%. Two groups of plants(early and late) were obviously segregated in the F2 and BC1 populations or F3 plant-lines, and the ratios of the early and late plants conformed to the complementary model of two pairs of genes. Under the short day and in the same crosses, the transgression of the F1s was not remarkable and the heading time distributions in the F2s appeared a single peak which were similar to the ones of the early group under the long day. This proved that the late heading of the F1s was mainly caused by stronger photosensitivity of themselves and that the two genes above belong to photosensitive genes. The complementary test and linkage analysis showed that the one complementary gene in the two indica varieties was allelic, and that it was associated with the Cl gene and their recombination value was about 27.78±1.82%. According to the experiemental results, the complementation of photosensitivc genes may be the principal reason causing the maturation period transgression of the remote hybrids of rice.

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Inheritance and Improvement of Grain Shape in indica Rice Shi Chunhai,Shen Zongtan 1995, 9(1): 27-32 .  Abstract ( )   PDF (201KB) ( )   Grain shape of paddy rice, including length width, thickness and ratio of length to width were quantitative traits controlled by polygene. The most of the traits in crosses were mainly controlled by additive genetic effects and had higher genetic advance and the range of their heritabilities in broad and narrow-sense were 28.3%-94.0% and 4.0%-83.2%, respectively. There were closely relationships among grain length, grain width and ratio of length to width. Paddy grain length and ratio of length to width could be improved with heavier panicle and more panicles in higher selecting pressure. Using above methods of selection, Zhenong 928 and Zhenong 937 with preferable paddy grain shape and yield potential have been bred.

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Estimation of Relationship between Rice Yield and Panicle-Grain Structure Wang Lei,Zhu Defeng,Chen Xichun,Xie Fuxie,Cai Tichang,Gao Meili,Ji Xiping,Zhang Shenlong,Zheng Chaohua,Zhang Dibiao 1995, 9(1): 33-39 .  Abstract ( )   PDF (236KB) ( )   The rice yield is composed of panicles, the filled grains per panicle and the weight of 1000 filled grains. The theoretical rice yield is defined by their product. However, sometimes there are considerable discrepancies between theoretical and observed yields. One general model is proposed to approximate yield structure: yield=theoretical yield + linear adjustment + random error. Based on Bayes estimates, yield estimation in one area is obtained by combining estimates for different varieties. Similarly yield estimation covering different areas is given by combining estimates over these areas. Also, the accuracy of yield estimation for one variety with small sample size is expecting to be improved by borrowing strength from other varieties in the same area.The corresponding variation of these estimates is given. Data sets obtained from Shaoxing and Fuyang in Zhejiang province are analyzed as an illustration of the proposed methods.

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Agricultural Production Resources Allocation: Rice Input and Output Analysis Huang Jikun,Wang Qiaojun,Chen Qinggen 1995, 9(1): 39-44 .  Abstract ( )   PDF (376KB) ( )   Rice is the most important staple food in China. Using this vital crop as a case study, a production function is estimated based on time series and cross sectional data(by province). The estimated coefficients then are compared with the price ratio of output and input. The results indicate a larger misallocation of agricultural resources in rice production in China. In the fertilizer application, the poor allocation is mainly due to the unbalance of fertilizer distribution over regions. While in the labor use, a great overuse is revealed in all production regions, indicating the importance of shifting the labor force farming to non-farming sectors. ReplaceFont('ChDivSummary','以我国的最主要农作物水稻为例子，根据生产函数模型和资源配置优化原则，对我国稻区水稻生产的投入和产出进行综合分析。结果表明，目前农业生产在资源的利用上存在着极大的浪费。在化肥总用量上存在着地区间的不平衡；在劳动力使用方面，投入水平已经大大超过经济合理的界限。');ReplaceFont('EnDivSummary','Rice is.the most important staple food in China.Using this vital crop as a case study.a production function is estimated based on time series and cross sectional data(by province).The estimated coefficients then are compared with the price ratio of output and input.The results indicate a larger misallocation of agricultural resources in rice production in China.In the fertilizer application,the poor allocation is mainly due to the unbalance of fertilizer distribution over regions.While in the labor use,a great overuse is revealed in all production regions,indicating the importance of shifting the labor force farming to non-farming sectors.');if(document.getElementById('ChDivSummary') != null && document.getElementById('ChDivSummary').innerHTML!=""){CutSpan('ChDivSummary',500);DisplaySpanDiv('ChDivSummary');ClearSummaryOnLoad('SummaryLinkChID','SummaryLinkEnID');} if(document.getElementById('EnDivSummary') != null && document.getElementById('EnDivSummary').innerHTML!=""){CutSpan('EnDivSummary',1000);DisplaySpanDiv('EnDivSummary');ClearSummaryOnLoad('SummaryLinkEnID','SummaryLinkChID');}ReplaceChar1('ChDivSummary');ReplaceChar('ChDivSummary');ReplaceChar1('EnDivSummary');ReplaceChar('EnDivSummary');

研究简报

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Genetical Studies on Seedling Leaf Color in Purple Rice Mou Tongmin,Li Chunhai,Yang Guocai,Lu Xinggui 1995, 9(1): 45-48 .  Abstract ( )   PDF (237KB) ( )   The purple rice plants OPL and PL184 were segregated from normal green rice varieties Ketan Nangka and W6184S in 1988 and 1990, respectively. No segregation appeared in the sequent two generations. Their agronomic traits were stable. These two kinds of purple rice plant were crossed with each other, F1 and F2 showed purple color and no separations were found, inferring that the two kinds of purple rice plant may have a same genotype. The two kinds of purple rice plant were crossed with 22 normal green color rice varieties, the F1s were all green color. Investigations on the leaf color in seedling stage were conducted in 14 crosses. F2s from the crosses between W9056S, W8013S and PL184 had ratios of 3:1 for green:purple, indicating one pair of genes differences between them. The ratios of green:purple in F2s from the crosses between Shuangguang S, Zhenshan 97A, Mi'ai 64 S, Petai 64S, Yuetai A, W91273S and PL184 were 13:3, indicating the differences between them are based on two pairs of genes with one inhibitory gene. When the purple rice plants were crossed with W6068S. Annong S, 3285S, W91238S and E47S, the ratios of green:purle in F2s were accorded with the model of 55:9, indicating the differences between them are based on 3 pair of genes with one inhibitory gene. F2 from the cross HN5S/PL184 had a ratio of 229:27 for green:purple, making known the difference between them is based on 4 pairs of genes with one inhibitory gene. In the backcross Zhenshan 97A/PL184 PL184 and HN5S/PL184 PL184, the ratios of green:purple were 1:1. However, the ratio of green:purple in triple cross F2 of Shuangguang S W9056S/PL184 was 113:15, indicating the inhibitory genes in W9056S and Shuangguang S are non-allelic. To sum up, the expression of purple leaf color in OPL and PL184 is probably controlled by 3 pairs of basic genes and 2 pairs of inhibitory genes. It is possible for combining the purple leaf color and PGMS or TGMS or CMS.

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Discussion of Tester of Wide Compatibility in Three-line indica-japonica Hybrid Rice Gao Yong,Teng Lisheng,Shen Zongtan 1995, 9(1): 49-52 .  Abstract ( )   PDF (146KB) ( )   Using maintainer lines as testers of wide compatibility(WC) proved to be helpful for the development of indica-japonica hybrid rice in three-line system. Maintainer lines Digu, Zhenshan 97, Hanfeng and 76-27, when used as testers, could reveal WC differences among different varieties. The two parental lines, male sterile and restorer lines, carrying the identical or different WC genes would be useful for improvement of seed set on an indica-japonica hybrid rice.

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Response of Early-season Hybrid Rice to Foliar Loss:A Simulation to Damage by the Rice Leaffolder, Cnaphalocrocis medinalis(Lepidoptera:Pyralidae) Chen Zhongxiao,Feng Mingguang,Hu Guowen,Pan Qunwei 1995, 9(1): 53-56 .  Abstract ( )   PDF (145KB) ( )   A field trial was conducted under natural ecological conditions and regular management to evaluate the effect of the rice leaffolder, Cnaphalocrocis medinalis, damage on the yield of early-season hybrid rice (Shanyou 402) by artificial defoliation. Foliar area of plants were cut off at the rate of 5%-30% at early tillering, peak tillering, elongation, booting, and milky stage, respectively, with each treatment including four 1 m2 replications. The average yields from the plots defoliated at peak tillering were significantly higher than that of the control whereas the yields from the plots defoliated at the milky stage were lower than that of the control. Thus, the hybrid plants were apparently tolerant to foliar injury at tillering. This indicates that the current control thresholds recommended for the leaffolder should be reevaluated and that no spray one month after transplanting should be an acceptable practice for the strategy of the leaffolder control.

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Activity and Degradation of Londax in Paddy Field Tao Bo,Su Shaoquan 1995, 9(1): 57-59 .  Abstract ( )   PDF (100KB) ( )   The activity and kinetics of Londax in the paddy field were presented in this paper. The degradation of Londax was fast at initial period. The half-time were about 3-5 days and 11-15 days in water and soil respectively. Activity of Londax were increased with increasing pH and temperature of water. Activity of Londax varied in different water resources, the sequence of activity of Londax were in underground water>river water>distilled water.