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10 July 1996, Volume 10 Issue 3 Previous Issue    Next Issue
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研究报告
综述与专论
研究简报


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研究报告

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Genetic Analysis of Grain Plumpness of Hybrids between indica and japonica Rice Gu Shiliang,Hui Dafeng,Zhu Qingsen 1996, 10(3): 129-137 .  Abstract ( )   PDF (518KB) ( )   Five crosses were obtained by crossing 4 japonica wide compatibility varieties with 4 ordinary indica ones. The grain plumpness for these materials was analysed with additive-dominance genetic models of plant and endosperm genotypes. The main results are as follows: 1 )The differences of grain plumpness among crosses were obvious. Those from crosses as Ce 03×Yangdao 4 and Lunhui 422×3037, both parents and progenies were high, poor grain plumpness of F1 generations was not a problem. The generations from 02428×Minghui 63 had high values despite their parents' low expression. This shows that under certain genetic backgrounds, the plumpness of grain could be improved by some external supplementary genes, indicating that there are other methods of improving grain plumpness of the hybrids besides 'getting high with high'. Two parents of low grain plumpness could get possible high plump hybrids. The grain plumpness for generations of low parent PC311 with high parent Yangdao 4 tallied well with additive genetic model. The grain plumpness of the descendants from low parents PC311×IR36 was low with few exceptions. 2)Single and joint genetic analysis of grain plumpness of several crosses showed that the increasing effect of Yangdao 4 and Ce 03 and decreasing effect of IR36 and PC311 were obvious. The effects could be explained by joint additive-dominance models of plant and endosperm genotypes. Yangdao 4 and PC311 had the strongest increasing and decreasing genes, respectively. But the grain plumpness of descendants of 02428 and Minghui 63 was mainly caused by positive dominant effect. In the cross PC311×IR36, non-genetic variation played a big role. The genetic analysis for two crosses with Yangdao 4 had high determination coefficient. Over half of variation among generations could be explained by the additive model. Genetic analysis was reliable. In other crosses, the genetic determination coefficient was very low(0.17). The goodness of fit test of genetic model was significant, indicated that besides additive-dominance, other factors, such as epistasis, might affect grain plumpness.

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Morphological and Cytogenetical Studies of the Hybrids between Oryza sativa and Oryza officinalis Yan Huihuang,Hu Huiying,Fu Qiang Yu Hanyong,Tang Shengxiang,Xiong Zhenmin,Min Shaokai 1996, 10(3): 138-142 .  Abstract ( )   PDF (578KB) ( )   Three interspecific crosses involving two accessions of Oryza officinalis with brown planthopper(BPH) resistance and two improved susceptible lines of O. sativa were attempted, and F1, F2 and BC1F1 hybrids were prepuced through embryo culture. The F1 hybrids shared traits from O. officinalis such as purple stigma, long awn and BPH resistance, and were male sterile due to the low amount of chromosome pairing(0.77 bivalents) or failure of anther formation;nevertheless, one F2 plant with 2n =46 was unexpectedly obtained. BC1F1 plants resulted from backcrossing to O.sativa were allotriploid (AAC) with a chromosome configuration of 12.25 Ⅰ+11.85 Ⅱ+0.01Ⅲ at metakinesis Ⅰ(MI).

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Genetic Correlations Analysis of Seed, Cytoplasm and Maternal Plant for Nutrient Quality in indica Rice (in English) Shi Chunhai,Yu Yonggui,Xue Jianming,Yang Xiaoe,Zhu Jun 1996, 10(3): 143-146 .  Abstract ( )   PDF (105KB) ( )   Nine cytoplasmic male sterile lines and five restoring lines were used in an incomplete diallel cross for analyzing genetic correlations of nutrient quality traits(protein content,protein index, lysine content, lysine index and the ratio of lysine content to protein content) of milled rice in indica rice(Oryza sativa L.). The results indicated that the genetic correlations of seed, cytoplasm and/or maternal plant are responsible for genetic correlations of most pairwise nutrient quality traits. The seed additive and dominance correlations, cytoplasmic correlations, maternal additive and dominance correlations for most pairwise traits studied were significantly positive. Some of the pairwise traits had negative genetic correlations especially for the traits between nutrient quality traits and the ratio of lysine content to protein content. Indirect selection for those traits with additive correlations was better than with dominance correlations. But the dominance correlations could be effectively used in hybrid rice breeding. The cytoplasmic correlations could be applied in both conventional crossing breeding and hybrid rice breeding.

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Flowering and Grain-filling Characteristics of Inter-subspecific Rice Hybrid Xieyou 413 Xu Rensheng,Tao Longxing,Yu Meiyu,Wang Xi 1996, 10(3): 147-152 .  Abstract ( )   PDF (409KB) ( )   In pot experiment, the comparative study on the flowering and filling characteristics of inter-subspecific rice hybrid Xieyou 413, its restorer line Zhong 413 and indica rice hybrid Shanyou 10 was conducted. The results showed Zhong 413, Xieyou 413 and Shanyou 10 were the highest, second and the lowest respectively in total grain dry matter per panicle. Seed setting rate for Zhong 413 and Xieyou 413 was nearly the same, 80.8% and 83.9% respectively, which was significantly higher than Shanyou 10(70.5% ). Under the circumstances, the difference of productivity of various rice hybrid crosses and the restorer line was mainly related to their flowering and filling characteristics,i.e. the concentration of floret flowering for a panicle and the filling difference of superior grains on top part of the panicle and proximal inferior grains. The more concentrative the floret flowering for the panicle is, the less the difference of filling and ripening for superior and inferior grains is, the higher the yield for a panicle. In the paper, the short flowering duration for a panicle used as the breeding goal for inter-subspecific rice hybrids is also discussed.

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Studies on the Theory of Two-step-filling of indica Rice Cultivars(Oryza sativa)(in English) Ma Guohui 1996, 10(3): 153-158 .  Abstract ( )   PDF (301KB) ( )   This paper focused to study the filling theory on two-step-filling(TSF). The results showed that the TSF performed not only in hybrids but also in conventional varieties and this performance was operated by the processes of simultaneous step up filling(SSUF) and differential step up filling(DSUF) in vigor spikelets(VSs) and weak spikelets(WSs); the TSF would not be demonstrated clearly under the stronger SSUF without DSUF or with weaker DSUF, while the TSF would express very clearly under the opposite case. The strong SSUF associated with the earlier and faster grain filling and much more repartition so that it is helpful to improve grain plumpness and seed setting rate. This paper has given a proposed model on accumulation of photoproducts in spikelets. For the photosynthetic accumulations, the much stronger SSUF with the absence of the process of DSUF is the best character, the strong SSUF with effective DSUF is better one, but the weak SSUF with weaker DSUF or with worse DSUF should be avoided for the cultivation practices and the breeding programme.

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Effect of Blue Light on the Respiration of Rice(Oryza sativa) Seedlings Yu Rancai,Pan Ruichi 1996, 10(3): 159-162 .  Abstract ( )   PDF (253KB) ( )   Effect of blue light on the respiration of rice seedlings was studied. The respiratory rate of leaves in blue-light-grown seedlings was about 1.5 times over that in white-light-grown seedlings. Measurement of activities of key enzymes in respiratory pathways showed that the activities of pyruvate kinase and malate dehydrogenase were higher in blue light treatment. Using respiratory inhibitors, we have demonstrated that malonic acid inhibited 76%of total respiration in blue-light-grown seedlings and 70% in white-light-grown seedlings, and Na3PO4 only inhibited 24% and 32% of total respiration in blue-light and white-light-grown seedlings respectively. Those results indicated that the enhancement of seedling respiration caused by blue light was mainly from strengthening EMP-TCA pathway. The leaf ATP content was increased after blue light irridiation.

综述与专论

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Some Consideration on Prehistorical Rice Culture, Landrace Development in China,and japonica-indica Hybridization of the Present Cultivars: Statistical studies on excavated rice kernels at the delta of Yangtze River Chao-Hwa Hu 1996, 10(3): 163-172 .  Abstract ( )   PDF (822KB) ( )   Measurement of excavated rice kernels of Hemudu, China revealed that seed size(L/W ratio) varied from 1.8 to 3.8 with a mean of 2.75 which fell well into the "normal distribution". A comparison was made firstly to the rice seeds born on F2 plants population of short-grain (glutinous, sd 1) and long-grain (nonglutinous, sd6) hybrid of California semi-dwarf cultivars. They all fell into the same category of variation with only mode difference. Then a comparison was further made with data reported by Wasano(1994), 5000 to 7000 years old kernels excavated from six sites including Hemudu at the delta of Yangtze River. It showed similar continuous variation although slightly different among sites. Judging the results from the above, the so-called subspecies, japonica and indica, or keng-hsien polymorphism has not showed up at the time of prehistoric China. The broad genetic variability of seedshape found in Hemudu suggested that outcrossing pollination took place in which characteristic of wild rice is remained. Race development was possibly automatic after rice of proto-type became a self-fertilization of an annual crop on the time of dissemination. It is assumed that segregation of seed-shape, short to long, was derived from originated heterogeneous population. They gradually became homogeneous and were accelerated under the pressure of natural environment and associated with human efforts resulted in "disruptive selection" of seed shape when these rice dispersed into north and south peripheries. This can be comparable to those crosses of japonica-indica grown them into cool and warm locations. Discussion was extended to the pattern difference of esterase isogenic genotype found in wild rice in China whether or not related to keng-hsien phenotype differentiation.

研究简报

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Screening of Resistant Resources and Genetical Analysis of Resistance to Whitebacked Planthopper in Rice Li Ximing,Liu Guangjie,Ma Liangyong,Hu Guowen,Min Shaokai,Ma Jufa 1996, 10(3): 173-176 .  Abstract ( )   PDF (234KB) ( )   Six rice varieties resistant to whitebacked planthopper(WBPH) were found by Standard Seedbox Screening Test in 18 rice varieties. Genetical analysis of resistance showed that a single dominant gene governs the resistance to WBPH in Shiyazhan and 5006, and a single recessive gene governs the resistance to WBPH in Baigannuo and Nabeshi.

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Evaluation of Some American Rice Cultivars to Bacterial Leaf Blight and Bacterial Leaf Streaks Zhang Hongsheng,Lu Zhiqiang,Han Liang,Zhu Lihong 1996, 10(3): 177-180 .  Abstract ( )   PDF (215KB) ( )   Resistance of 42 rice cultivars, imported from the United States, to the bacterial leaf blight (BLB, Xanthomonas oryzae pv. oryzae) and bacterial leaf streaks (BLS, X. oryzae pv. oryzicola) were evaluated. The results showed that 28.6%-85.7% of tested cultivars were resistant or moderately resistant to the pathotype Ⅳ and Ⅴ of BLB, and 57.2%-83.4% were resistant or moderately resistant to the strains BS39 and BS93 of BLS. IR36M4 and Gulfrose were resistant to two different diseases. Those cultivars with high resistance to BLB were also more resistant to BLS. The possible relationship between two resistance in rice cultivars were discussed.

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Studies on the Qualitative and Quantitative Resistance of Rice Cultivars to Blast Disease Zhu Xiaoyuan,Yang Qiyun,Huo Chaobin,Wu Shangzhong 1996, 10(3): 181-184 .  Abstract ( )   PDF (239KB) ( )   Nine rice cultivars were evaluated for blast resistance relatively to the partially resistant check IR36 and the susceptible check B40, based on the measurement of resistant spectrum, lesion size, lesion density and diseased leaf area. Results indicated that three cultivars, namely Sanhuangzhan 2, Sanluzhan 7 and Meisanwu 2 appeared high qualitative and quantitative resistance either under artificial inoculation with 220 isolates of Guangdong Province or under a wide range of environmental diverse population of Pyricularia grisea, which may be considered to contribute the highly and stable blast resistance in different latitude in rice growing zone in China. But in some cases, the level of qualitative and quantitative blast resistance is not always positively correlated in the same cultivar.

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Studies on Estimation Methods of Larva Density of Hydrellia sasakii Qing Houguo,Ye Zhengxiang,Li Hua 1996, 10(3): 185-188 .  Abstract ( )   PDF (118KB) ( )   According to the relation between zero specimen frequency(P0) and larva density(m) of Hydrellia sasakii investigated in the field, with the help of methods of population density estimation put forward by Iwao, Nachman, Gerrard, 5 formulae estimating larva density(m) of Hydrellia sasakii with the help of zero frequency(P0) were formulated: (1) P0=(0.896+0.023m)/m(-0.104+0.023m);(2) m=exp[0. 913ln(-lnP0) + 0.0258];(3)m=1.013(-lnP0)0.913;(4) m=1.019(-lnP0)0.924;(5) m=0.9999(-lnP0)0.971. In which, (5) formula was obtained using the theory value of formula (1) and (2) coordinated m=α(-lnP0)β. The comparison of estimation precisions and field application test, consistently shows that formula (5) estimation error was the minimum, precision was the maximum.

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Study for Multi-seedling Percentage in Rice Hu Huiying,Sun Zongxiu,Cheng Shihua,Yan Huihuang 1996, 10(3): 189-190 .  Abstract ( )   PDF (127KB) ( )   The result indicated that there were 81 varieties with multi-seedlings among 5942 rice varieties tested, which account for 1.36% of total checked varieties. The multi-seedling percentage in a variety was low(0-3%).

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Specific Protein from Germinating Rice Seed Zhong Boxiong 1996, 10(3): 191-192 .  Abstract ( )   PDF (167KB) ( )   Protein extracted from embryos of rice by phosphate buffer and precipitated by TCA were used to study the protein differences in the dormant embryos and germinating embryos by the method of two-dimensional electrophoresis. It was discovered that three neutral proteins with relatively low molecular weights found in the dormant embryos were gradually disappeared in the germinating embryos. However, two new proteins with pI=7.15,MW=16kD and pI=3.00, MW=59kD, were found in the germinating embryos.