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10 April 1997, Volume 11 Issue 2 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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The Diversity of Cytoplasmic Effects on Some Quantitative Traits in Hybrid Rice Wang Wenming,Zhou Kaida,Wen Hongchan,Zheng Jiakui,Zhu Yongchuan,Yuan Guoliang,Wan Xianqi 1997, 11(2): 65-69 .  Abstract ( )   PDF (934KB) ( )   Analysis on the diverse effects of cytoplasmic male sterility (CMS) was carried out in a 9×8 uncomplete diallele cross including 3 series of isonuclear-allocytoplasmic lines under 3 kinds of CMS background, i. e. 9 CMS lines, and 8 restorer lines, with split-split plot design. The effects of different CMSs on one trait are diverse from each other, so are the effects of one CMS on different traits. Besides, the effect of CMS consists of one or more of four components, namely, the GCA of CMS, the special GCA of interaction in CMS-maintainer combination which can be fixed in a certain sterile line, the SCA of CMS-restorer interaction and the SCA of CMS-maintainer-restorer interaction. Effects on 1000-grain weight were revealed significantly different among W-cms, D-cms and Kcms with identical effects on the other traits. Accordingly, a sterile line with multiple-cytoplasm and multiple cytoplasmic hybrid rice could be raised and exploited in hybrid rice production.

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Correlation between Eating Quality arid Physico-Chemical Properties of High Grain Qualitiy Rice Chen Neng,Luo Lijun,Zhu Zhiwei,Zhang Boping,Zheng Youchuan,Xie Lihong 1997, 11(2): 70-76 .  Abstract ( )   PDF (294KB) ( )   Multiple comparisons and the correlation coefficients between eating quality(EQ) and physico-chemical properties of 78 samples of high-quality indica and japonica rice varieties were studied. Physico-chemical properties included grain length (GL), length/width ratio(L/W),chalky grain, chalkiness, translucency, gelatinization temperature (GT,alkali spreading value ), gel consistency (GC), amylose content (AC) and protein content (PC). The results showed (1)A significant positive'correlation effect between EQ and GL factor and chalkiness factor,and a significant negative correlation effect between EQ and L/W factor. The order of significance of the three factors to EQ was GL > L / W > chalkiness. (2) A significant negative correlation effect between the translucent degree of japonica rice varieties and EQ. (3)For indica rice varieties, the varieties with low AC(<18. 6% ) were of good EQ, but those of high AC (24. 5 % )were of worse EQ. Indica rice varieties with high GC (76. 4 mm) were better than those of medium GC (52. 3 mrn) in EQ. Their GT (>4 grade)had no effect on EQ. (4) For japonica rice varieties, their AC, which was lower than 20%, or GC, which was higher than 73. 5 mm, or GT, which was higher than the sixth grade, had no significant effect on EQ.

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Studies on Combining Ability of the Main Economic Characters in Upland Rice Yang Guifen,Tao Dayun,Hu Fengyi,Yang Jianyi 1997, 11(2): 77-82 .  Abstract ( )   PDF (404KB) ( )   Analysis of the combining ability and the hereditability was conducted to improve Yunnan traditional upland rice by using the model (Burton 1951, 1959) based on the data obtained in incomplete diallel crossed with seven abroad medium or semidwarf improved upland rice accessions and seven Yunnan traditional upland rice varieties in 1993. The results showed that the combining abilities were different for different materials on one character or different strains on the same material, they were concerned with materials for GCA (general combining ability), SCA (special combining ability). The GCA of abroad upland rice was better than that of Yunnan's, selection of the researched characters was important for abroad or Yunnan upland rices, with particular reference to panicles per plant, spikelets fertility about abroad upland rices, and spikelets per panicle about Yunnan's. The SCA of the two kinds of varieties combining were significant or highly significant on panicles/plant, days to heading and spikelets/panicle. It's effective to improve Yunnan traditional upland rice by crossing the abroad with the traditional and verified by the fact of breeding, which should be used the traditional breeding method and polycross, the selection emphasis should be plant height, days to heading and combinations in earlier generations, and panicles/plant, spikelets/panlcle, grains/panicle, fertility and single plant in advanced generations. Slmultanlously the 14 parents were evaluated and were proposed good GCA's parents of IRAT216, IRAT104, Tos 2300, Mengwangu. At last. it was discussed that the effect of GCA, SCA to different breeding strategy, the possibility of improving Yunnan upland rice by crossing irrigated rice with upland rice.

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The Fertility Expression of Dual-purpose Genic Male Sterile Line Indica Rice Pei’ai 64S:Changes of NAD+-MDH and AP Isoenzyme during Spikelet Development Li Ping,Liu Hongxian,Wang Yirou,Zeng Shaoxi,Li Meiru,Zhang Xu,Lin Daoxuan,Chen Zhaoming,Liu Yanzhuo,Kong Qingni 1997, 11(2): 83-88 .  Abstract ( )   PDF (393KB) ( )   The dual-purpose genic male sterile line indica rice Pei'ai 64S and conventional rice cultivar Jingxian 89 were used as experimental materials. The mechanisms of fertility conversion and expression in the male sterile line were studied using PAGE to comparably analyse its changes of NAD＋-MDH and AP isoenzyme during pollen mother cell formation, reduction division and pollen ripening stage at spikelet development period. Results indicated that Pei'ai 64S sown on 25 February, 10 March and 30 March in 1993 was all sterile. Their pollen abortion percentage was above 99. 7% and the seed setting rate was below 0. 3%. Pei'ai 64S sown on 1 August 1994 was fertile with a seed setting rate above 19%. Conventional rice cultivar Jingxian 89 sown at the same time could all obtain normal grains with a seed setting rate above 68%. Furthermore, the abortion of Pei'ai 64S sown in 1993 was markedly related with the decrease of NAD＋-MDH enzyme activity in spikelet and anther during the polIen ripening stage. Its abortion was also closely related with the change of AP activity and isoenzyme components in the spikelet at pollen mother cell formation-reduction division stage. Pei'ai 64S sown in 1994 showed fertility which did not exhibit these changes. So we think that fertility expression of Pei'ai 64S could be related with fat metabolism at the initial stage in pollen development or its respiratory metabolism at the late stage of pollen development.

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The Relationship between Phytase Activity in Rice Seed and Germination (in English) Wen Tieqiao,Song Guoqing,Zhou Yong,Zhang Yang 1997, 11(2): 89-92 .  Abstract ( )   PDF (106KB) ( )   Phytase activity in Oryza sativa L. (tested cvs: Huda 242, Bin 064, Qionggeng 2 and Minghui 63 ) with an optimum pH of 5. 8 was discovered from extracts of dormant and germinative seeds, phytase activity has a direct bearing on seed germination. When phytase is inhibited, the seeds do not sprout. The phytase is activated by calcium and inhibited by glucose. Phytic acid substantially inhibits seed bud, and phytase can remove this inhibition.

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Relationship among Generation Rate of Superoxide, Resistance of Rice to Blast Fungi and Activation of Inducible Phenylalanine Ammonia-lyase, Chitinase,β-1,3-glucanase Xiao Shuangsuo,Wang Jun 1997, 11(2): 93-102 .  Abstract ( )   PDF (442KB) ( )   The generation of superoxide(O2-) in incompatible and compatible combinations among nineteen rice (Oryza sativa L. ) cultlvars and eight Pyricularia oryzae races or their hyphal metabolites (RBHM) had been measured. The O2- generation was enhanced in incompatible combinations but not in compatible combinations. Digitonln could induce O2- generation increased rapidly in rice seedlings and accompanied by the increase of their resistance to the infection by compatible blast pathogen. Dethyldithiocarbamate (DDTC), the inhibitor of cooper-type superoxide dismutase (SOD), could induce O2- generation seriously. N-ethylmaleimide (NEM), the scavenger of O2-, could induce the increase of rice SOD activity. Actinomycin D and cycloheximide could also induce O2- generation accompanied by the inhibition of SOD activity. The activity of phenylalanine ammonia-lyase (PAL) could be induced stronger and faster in incompatible system than in compatible system. However, the inducible PAL activity seems to be no specific relationship to rice resistance to blast infection because it could be induced by many different chemicals including digitonin, DDTC and NEM. The activity of chitinase and β-1,3-glucanase could not be induced by DDTC, NEM and digitonin. Their activation seems no relationship to O2- generation, and the signal transduction pathway for induction of their expression may not be similar to the pathway for PAL activation.

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Studies on Natural Population Parameters of Hydrellia sasakii Qin Houguo,Ye Zhengxiang,Li Hua,Luo Renhua 1997, 11(2): 103-106 .  Abstract ( )   PDF (249KB) ( )   The development period, survival rate and fecundity of natural population of Hydrellia sasakii 1-5 generations were studied in 1993 - 1995. The results show that the duration of first generation was the longest, the third and fourth generations were the shortest. The hatching rate of egg and the survival rate of larva were the smallest at first generation. It is higher at second to fifth generation. The survival rate of pupa of first generation was the lowest and hereafter increased generation by generation. The sex ratio of adults were 1: 1 around. The precede period of egg oviposition was 2 d or so at first generation, 1. 4 d at second generation and 1 d or so at third to fifth generation. There were no significant differences among the number of egg oviposition of female at second to fifth generation. It averages 24 granules or so per female. At first generation, it is less than 21. 9 granules per female. The longevity of adults of first generation was the longest and hereafter shortened generation by generation. The population trend index of fourth generation was the largest and that of first generation was the smallest. Ichneumonidae is a natural enemy of Larva. Tetrastichus hydrellia and Braconidae are natural enemies of pupa.

综述与专论

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Current Status and Prospects of Research on Intersubspecific (Indica-Japonica) Hybrid Rice (in English) Tao Ailin,Zhou Wenhua 1997, 11(2): 107-112 .  Abstract ( )   PDF (349KB) ( )   The current status of researches on intersubspecific (indica-japonica) hybrid rice in the past few years was reviewed. This paper suggests that solving the problem of low seed set of F1 depends on transfering of wide compatibility (W. C. ) genes to the parents of two-line or three-line so as to breed up W. C. sterile lines or restorer lines. Meanwhile, good W. C. parents will improve the plumpness of the grains of F1. collecting the parents with light photosensitivity may solve the problem of the maturation period transgression, which is helpful to solve the problem of plant height transgression. Ideotype breeding, which includes transfering of allelic semidwarf genes, selecting of the parents with good plant type and balanced relationship of source-flow-sink and with good rice quality and similar grain shape, will make the plant height amenable, improve the plumpness of the grains of F,, and weaken the phenomena of the segregation of rice quality. All the above will help intersubspecific hybrid rice transmit from experimental to commercial planting.

研究简报

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Embryological Studies on Apospory in Rice HDAR Yao Ailin,Cai Detian,Ma Pingfu,Zhu Hong 1997, 11(2): 113-117 .  Abstract ( )   PDF (174KB) ( )   An embryological investigation on the development of female gametophyte formation and embryogenesis in rice HDAR was made. The results revealed that the aposporous embryo sacs originated from certain somatic cells in the vicinity of megasporocyte. As aposporous initials developed simultaneously with megaspore mother cell and competed with each other,either multiple embryo sacs or sometimes only single embryo sac could be observed at later stage in one ovule. Their multiple embryo sacs differed extensively to each other in shape, structure, and polarity. Also, egg-cell in certain embryo sacs, which were difficult to determine their origins, possessed the capacity for parthenogenesis. The coexistence between apomictic ovary and sexual suggested that apospory in observed materials might be a typical facultative apomixis.

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Genetic Variability of Protein Content of Grain in Rice Hybrid Progenies He Guanghua,Xie Rong,Zheng Jiakui,Yin Guoda,Yang Zhenglin,Zuo Yongquan,Zuo Yongshu,Huang Jianguo,Shao Qiming 1997, 11(2): 118-120 .  Abstract ( )   PDF (178KB) ( )   P1, P2, F1, F2, B1, B2 in five combinations were used as materials and the genetic variability of grain protein content were analyzed. The results show protein content in rice grain belongs to quantitative traits controlled by polygene, F1 and backcross generations present approximately normal distribution in continuous variation. There are some plants whose protein content of grain are higher than parents with high content among segregating generations. Selection was undertaken beginning with low generations, it is probable to obtain fine individuals. Parents' protein content affects progenies, whereas the female parents have much bigger effect. It is beneficial to use parents with high protein content as female parents in breeding combinations.

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Screening and Preliminary identification of Somaclonal Variants Tolerant to Photooxidation in Oryza sativa L. Chen Yifeng,Sun Lihua,Zhu Yonglan 1997, 11(2): 121-123 .  Abstract ( )   PDF (118KB) ( )   A series of rice somaclonal variants with photooxidation tolerance have been screened and preliminarily identified. It is indicated that somaclonal variants (regenerating plants) from calli of mature caryopsis of 02428 and Chugoku 91 which are tolerable to photooxidation are also tolerant and that those from 842, Meixuan Minghui 63-38, Meixuan Minghui 63-53, and Guichao 2 which are sensitive to photooxidation display a wide spectrum from sensitivity to tolerance under photooxidative condition, among them (168 variants) from 4 sensitive parents 2 variants (numbered as 93012, 93236) have strong ability and 17 variants have medium ability against photooxidation. Decline of net photosynthetic rates of these tolerant variants is remarkably less than that of sensitive variants under photooxidative condition. Moreover it is initially proved in posterities of some variants that this type of variation is of genetic stability. We suggest that rice somaclonal variants with photooxidation tolerance provide a new source of variation which could be used in breeding rice cultivars with higher photosynthetic efficiency in the near future.

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Manipulation of Grain-filling Characteristics of Intersubspecific Hybrid Rice and Its Effect on the Yield Xu Rensheng,Tao Longxing,Yu Meiyu,Wang Xi 1997, 11(2): 124-128 .  Abstract ( )   PDF (363KB) ( )   In pot experiments of inter-subspecific rice hybrid Shanyou 413, higher level of IAA in rice plants, through IAA solution injected to the boot of the rice plant at booting stage, had little effect on the average weight and seed-setting of the superior grains located on the distal part of the panicle, nevertheless, significantly inhibited the filling of the inferior grains positioning on the secondary branches, which resulted in a longer "quiescent spell" before the beginning of the inferior grain filling and slower rate of the ovary expansion of the inferior grains. Consequently, the average weight and seed-setting of the inferior grains in treated plants was reduced to a large extent. Moreover, application of IAA to plants before heading promoted the abortion of the inferior florets. After heading, 3 top primary branches were clipped off and 20 μL lanoline, containing different quantities of IAA 0, 10 , 20, 30 and 40 ng/μL, were smeared onto the apex of the panicle axis. The results showed that clipping and only lanoline smeared decreased unfilled and partially-filled grain (UPG) percentage of the inferior grains on the secondary branches of the 3 base primary branches from 47.7 % of check to 8.2%. However, when the clipping and IAA applied, the UPG percentage was nearly restored to the level of check except the highest IAA quantity used, which indicated that as the influence on the filling of the inferior grains was concerned, IAA was able to substitute for the superior grains. It is deduced that the superior grains inhibit the filling of the inferior grains by the "apex dominance". When the inhibition occurs, the inferior grain filling can not be improved though the assimilate supply is quite rich. In field yield test of 1993-1994, uniconazole was proved to increase yield of intersubspecific rice hybrid Xieyou 413 and Shanyou 413 in advantage of above 10% to check, by ameliroating the filling of the inferior grains and resulted higher seed-setting. The possibility for fulfillment of the highest yieldingpotential in inter-subspecific rice hybrids is also discussed.