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10 April 2000, Volume 14 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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Preliminary Detection of Quantitative Trait Loci for Salt Tolerance in Rice GU Xing-you,MEI Man-tong,YAN Xiao-long,ZHENG Shao-ling,LU Yong-gen 2000, 14(2): 65-70 .  Abstract ( )   PDF (255KB) ( )   Restriction fragment length polymorphism (RFLP) and tillered plant line assessment were employed to detect the quantitative trait loci (QTLs) for salt tolerance at different stages of rice development from a BC 1 [Peta/Pokkali(salt tolerant)∥Peta(salt sensitive)] population. Phenotypic evaluation was conducted in hydroponic culture with (treatment) or without (control) 60 mol/m 3 NaCl. Three indices (ranking of salt injury, Na + content in shoot and the ratio of shoot fresh weight/dry matter weight) at seedling stage and ten agronomic traits in control and salt treated plants at mature stage were measured. Single point analysis of 43 polymorphic markers screened from 12 chromosomes identified a total of 15 markers that were significantly associated with the indices mentioned above. The results from linkage analysis revealed: 1) There were 4 putative QTLs for salt tolerance at the seedling stage and all of the positive alleles came from Pokkali; 2) The QTLs for the salt tolerance at the mature stage distributed in one or two linkage regions on six chromosomes where the favorite alleles dispersed in both parents; 3) Two QTLs in the vicinity of RG678 and RZ400B RZ792 exhibited salt tolerance at both stages.

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A Molecular Map Based on an Indica/Indica Recombinant Inbred Population and Its Comparison with an Existing Map Derived from Indica/Japonica Cross in Rice LI Wei-ming ,TANG Ding-zhong ,WU Wei-ren ,LU Hao-ran ,A. J. WORLAND 2000, 14(2): 71-78 .  Abstract ( )   PDF (360KB) ( )   With the eventual purpose of precisely locating quantitative trait loci (QTLs) in indica rice, a molecular linkage map was constructed based on an indica × indica derived recombinant inbred (RI) population consisting of 131 (F6∶7 ) lines. The map consists of 160 RFLP markers detected by 113 rice and 28 wheat probes and 78 AFLP markers revealed by five Pst Ⅰ/ MseⅠ primer combinations. The heterozygosity rate of the population was close to the expectation, indicating that the population had a normal genetic structure. Segregation distortion was observed in six chromosomal regions, suggesting that abnormal segregation could happen even in an intra subspecies population. The map covers a length of 1435.8 cM, with an average distance of 6.38 cM between adjacent markers. A set of RFLP landmarks generated by the Japanese Rice Genome Program (RGP) was applied to allow comparison between our map and the RGP map. Both maps have nearly the same total map length regarding the coverage by common markers. Nine of 12 chromosomes showed complete linkage conservation in the two maps and rice chromosome 1 represented strong linearity to wheat group 3 chromosomes. Distinct organization between the two maps was evident. Four small inversions in chromosome arms 1S, 1L, 4L and 8L and nineteen additional loci mapping to all twelve chromosomes except chromosomes 5 and 6 were detected. Four regions on chromosome arms 2S, 7S, 10L and 11S exhibited no, or at least very low polymorphism resulting in obvious distal deficiencies in these regions of the indica map. The conservation of duplicated fragments between chromosome 11 and 12 was not detected in the indica map. Chromosome rearrangement involving in genome evolution in O. sativa is discussed.

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Further Report on the Incorporation of the Rice Blast Durable Resistance into Hybrid Rice ZHOU Shao-Chuan ,ZHU Xiao-Yuan ,JIANG Yan-fang ,YANG Qi-yun ,KE Wei ,MIAO Ruo-wei ,WU Shang-zhong 2000, 14(2): 79-82 .  Abstract ( )   PDF (114KB) ( )   By crossing two durably resistant cultivars (Sanhuangzhan 2, Sanluzhan 7), and two resistant cultivars (Wai xuan 35, Aisanluzhan), with two popular sterile lines susceptible to rice blast (Guang A,Bo A), their hybrid rice combinations were studied with respect to qualitative resistance, quantitative resistance and field resistance in different blast conducive areas. Results indicated that the combinations with durably resistant donor showed the same durably resistant characteristics as correspondingly durably resistant cultivars. Quantitative resistance and field resistance in different blast conducive areas could be as indicators of durability of resistance. Quantitative resistance was closely related to field resistance in different blast conducive areas, and might be an important indicator of durable resistance to blast. These results suggested that it would be possible to breed for durable resistance to rice blast by means of selecting quantitative resistance which could be tested under artificial inoculation in greenhouse.

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Dynamic Change of Chalkiness and Observation of Grain Endosperm Structure with Scanning Electron Microscope under Controlled Temperature Condition CHENG Fang-ming ,HU Dong-wei ,DING Yuan-shu 2000, 14(2): 83-87 .  Abstract ( )   PDF (428KB) ( )   Based on the experiment with two chalkiness types of indica rice variety (Xinong8116 and Guang’er’ai 104) and two different temperature treatment (the daily average temperature was 33℃ and 23℃, respectively) in climatic chamber, chalkiness change of rice grain during grain filling stage and its relationship with the endosperm starch structure characteristics such as starch shape, size, developing degree and arrange pattern which was observed by scanning electron microscope were analysed.The result showed that the key stage of the chalkiness change of rice grain during the filling stage was from 5 days to 15-20 days after heading, but at the other stage the chalkiness change was not clear; the difference of chalkiness change between 33℃ high temperature treatment and 23℃ proper temperature treatment was mainly at the stage of 10 days to 20 days after heading; through the observation of grain endosperm structure with scanning electron microscope, it was found that the distinguish between “uncovered endosperm starch” and “ covered endosperm starch” had close relationship with starch developing degree in endosperm cell, no inevitable relative to the chalkiness type of rice variety.

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Biological Effects of Lilibao on Rice Plant TAO Long-xing,HUANG Xiao-lin,WANG Xi,YU Mei-yu 2000, 14(2): 93-97 .  Abstract ( )   PDF (256KB) ( )   Using two hybrid rice combinations and two conventional varieties as materials, the experiment was carried out under different season in Hangzhou, China and Bangalore, India . When the Lilibao (a plant growth substance including GA 3 and PP 333 , meaning every grain will be filled) was applied at initial heading stage, the panicle neck length could be enhanced by Lilibao treatment, the senescence of the latest three leaves was delayed; apical dominance inter grain could be regulated, and resulted in increasing grain weight and yield.

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Evaluation and Utilization of Antagonistic Bacteria against Rice Sheath Blight CHEN Zhi-yi ,XU Zhi-gang ,GAO Tai-dong ,NI Shou-kun ,YAN Da-fu ,LU Fan ,LIU Yong-feng 2000, 14(2): 98-102 .  Abstract ( )   PDF (166KB) ( )   One thousand two hundreds seventy four bacterial isolates were obtained from paddy soil, sclerotia of Rhizoctonia solani, sheath blight (ShB) lesions and healthy rice plants. Their antagonism to Rhizoctonia solani were tested in vitro. Sixty one strong antagonistic strains, 727 moderate and weak antagonistic strains and 486 non-antagonistic strains were 4.8%, 57%, and 38.1% of the total, respectively. Twenty four strains were used for biocontrol of ShB at rice tillering stage of rice in pots, 6 strains with over 60% of control effect on ShB were further tested biocontrol in the field plots. The results indicated that strain B-916 was the best in control effect on rice ShB in the field. Performance test of B-916 of biocontrol on ShB was continuously carried out during 1994-1997 at three sites (Jiangyan, Wujiang, and Jurong Cities, Jiangsu Province), the results showed that ferment product of B 916 which could effectively control rice ShB infection under field conditions, has 50.0% to 81.9% of control effect on ShB.

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Effect of Chilling Induced Photoinhibition Stress on Chlorophyll Fluorescence in Flag Leaves at Heading Stage in Indica Rice Varieties with Different Cold Tolerance LI Ping,LI Xiao-ping,CHEN Yi-zhu,LIU Hong-xian 2000, 14(2): 99-92 .  Abstract ( )   PDF (255KB) ( )   The possible mechanisms of preventing chilling photoinhibition damage in indica rice varieties with different cold tolerance i.e. Qinghua 6 (cold sensitive) and Guishan’aixuan 3 (cold tolerant)were explored using PAM pulse modulation fluoremeter to analyse its chlorophyll fluorescence in flag leaves. The results indicated that after chilling induced photoinhibition stress the initial fluorescence Fo in the flag leaves was increased and its Fv/Fm ratio was significantly decreased which were greater than those in the dark chilling treatment. Comparing the varieties with different cold tolerance, the rise of Fo and decline of Fv/Fm were more significant in Guishan’aixuan 3 than those of Qinghua 6. However, its Fo and Fv/Fm recovered fast after treating for 5 h at room temperature with weak light (20 μmol photons/m2·s). The fluorescence quenching analysis also expressed that photochemical quenching (qP) decreased and no photochemical quenching (qN) increased by chilling photoinhibition. The effect of DTT treatment on qP was not significant, it markedly inhibited the increase of qN. The decrease of qN in Guishan’aixuan 3 was more significant than that of Qinghua 6, but its recovery was faster at room temperature with weak light. It was considered that occurrence of photoinhibition in indica rice was induced by low temperature. It was shown that the degree of chilling photoinhibition was not the only factor to cause cold damage as ability of recovery of the cold tolerance of the varieties also reflected its effect on photoinhibition. Since Guishan’aixuan 3 had a stronger ability of preventing chilling photoinhibition than Qinghua 6, this may be related to the capacity of xanthophyll cycle pool and regulatory role of zeaxantin

综述与专论

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Advances on Transferring Elite Gene from Wild Rice Species into Cultivated Rice ZHONG Dai-bin,LUO Li-jun,YING Cun-shan 2000, 14(2): 103-106 .  Abstract ( )   PDF (154KB) ( )   There are two cultivated and twenty wild species of genus Oryza. These wild species of Oryza with 2n=24 or 48 chromosomes representing AA, BB, CC, BBCC, CCDD, EE, FF, GG and HHJJ genomes are an important reservoir of useful genes. Resistance to biotic and abiotic stresses as well as useful traits of wild species are described, and the recent advances on utilization of wild species for transferring elite gene into cultivated rice from wild species are summarized. The molecular mapping of alien genes introgressed from wild species into rice and mechanism of alien introgression as well as the prospects of utilization of wild species are also discussed.

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Current Knowledge and Prospects of Breeding Rice Varieties for Problem Soils LI Yang-sheng,LI Da-mo,ZHOU Jian-lin,LI Shao-qing 2000, 14(2): 107-111 .  Abstract ( )   PDF (147KB) ( )   Problem soils where rice grows can be divided into two classes according to whether toxicity or deficiency predominate. The strategies of their amelioration and utilization for agriculture depend on predominant stress factors in a range of different problem soils. To increase sustainably productivity on problem soils, it is a important approach to develop new rice varieties appropriate to these soils. Current knowledge and prospects of breeding rice varieties for problem soils, including screening techniques, breeding methods, genetic variability etc., have been discussed.

研究简报

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Contribution of Rice Genetic Improvement to Yield Increase in China MA Zhong-yu,WU Yong-chang 2000, 14(2): 112-114 .  Abstract ( )   PDF (141KB) ( )   On the basis of the establishment of simulation model for analyzing the share of rice improvement in contribution of technological advance to rice yield increase, the contribution of rice genetic improvement, fertilizer input and management to rice yield increase in five provinces in China were analysed by using the established model. The result shows that, of the contribution of technological advance during 1985 to 1994, the average share of improved rice is 29.2%, fertilizer input 43.2% and management 27.6%. Among the five provinces, there are three major matches of above mentioned technological elements, which are fertilizer dominated, improved variety dominated and integrated fertilizer, improved variety and cropping management match, The rational measures for raising rice yield in future were discussed and suggested. In particular, the government needs to further increase the investment into the research of rice genetic improvement in order to maintain a higher share of rice improvement in contribution to rice yield growth, which is the most cost effective measure for enhancing yield. At the same time, much effort should be devoted to the improvement of integrated approach of fertilizer, improved variety and cropping management in order to improve the resource use efficiency of rice production.

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Correlation of Indica Japonica Classification and Morphological Character of Yunnan Nuda Rice Cultivars ZENG Ya-wen,XU Fu-rong,SHEN Shi-quan,DENG Jia-you 2000, 14(2): 115-118 .  Abstract ( )   PDF (115KB) ( )   Correlation between indica japonica classification index and morphological character of 20 cultivars of Yunnan nuda rice, two wide compatible cultivars (02428, and Dular) and four indica japonica tested cultivars were studied by using Cheng’s and Yu’s classification methods. The results indicated that 20 Yunnan nuda rices have 13 varieties and 69 forms, japonicaclinous rice have higher proportion in tested cultivars, and have good wide compatibility. There are significant correlation coefficients in Cheng’s indica japonica rice classification index and other characters especially anther length, internode length and plant height. It is suggested that differentiation of indica japonica rice of the primitive Yunnan nuda rice depended on temperature, and it was correlated with latitude and elevation.

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Preliminary Analyses of the Effect of Genetic Purification of Thermosensitive Genic Male Sterile Line Peiai 64S by Anther Culture ZHOU Yuan-chang,LIN Li-hui,JIANG Shu-ye,JI Biao-jun,MAO Da-mei,CHEN Qi-feng,LI Wei-ming 2000, 14(2): 119-121 .  Abstract ( )   PDF (125KB) ( )   Ninty one doubled haploid plants from thermo sensitive genic male sterile line Peiai 64S core seeds were obtained by anther culture, and their H2, H3, H4 generations pollen sterility were observed under the natural climatic condition in Fuzhou (26°05′N), China. Results showed that:(1)the fertility extensively segregated in the H2 generation and could be mainly divided into three types: completely sterile (Peiai 64HS) with more than 99.8% pollen sterility and long stable sterility duration; basically fertile (Peiai 64HF) with high pollen fertility and no stable sterility duration in the whole; intermediate fertile (Peiai 64HM) with high pollen sterility instability and short pollen sterility duration. (2)Peiai 64HS, Peiai 64HF, Peiai 64HM had the same sterility expression tendency in H2, H3 and H4 generations. (3)Peiai 64HS had much longer stable sterility duration, stabler sterility and higher pollen sterility than Peiai 64S core seeds. Results also indicated that Peiai 64S core seeds were genetically heterozygous in the fertility and anther culture was useful to Peiai 64S in genetic purification.

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Changes of Root Exudate of Indica Japonica Hybrid Rice and Its Relation to Leaf Physiological Traits SHEN Bo,WANG Xi 2000, 14(2): 122-124 .  Abstract ( )   PDF (160KB) ( )   Using indica japonica hybrid rices of Ⅱyou2070, Ⅱyou419 and their restorer lines 2070, Zhong419 as materials, the changes of root exudate after initial heading stage were studied. The results show that root activity of indica japonica hybrid rices were higher than their restorer lines, especially from initial heading stage to milk ripening stage, however, the amount of root exudate rapidly decreased after milk ripening stage. This dynamic change was consistent with the photosynthesis rate and chlorophyll content of leaf at different levels and green leaf areas above the ground.

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Ecological Control of Barnyardgrass by Different Morphological Type Rice XU Zheng-hao,YU Liu-qing 2000, 14(2): 125-128 .  Abstract ( )   PDF (161KB) ( )   The growth character of barnyardgrass [Echinochloa crusgalli (L.) Beauv. var. mitis (Pursh) Peterm.] in mixture transplanting with different morphological type rice varieties (combinations) were studied. The hybrid rice combination Ⅱ you 2070 with the plant morphological type of long stalked and great canopy (LSGC) reduced the plant height, leaf area index, plant dry weight, panicle length, tiller number and spikelets per panicle of barnyardgrass significantly in the transplanted rice. The competitive ability of LSGC with barnyardgrass was more powerful compared with the plant morphological type of middle stalked and medium canopy (MSMC) and the plant morphological type of short stalked and small canopy(SSSC). The yield components of indica hybrid rice with LSGC was no decrease markedly under barnyardgrass interference of 50 plants per square meter. However, the yield components of japonica rice with SSSC declined seriously resulting in 40 percent loss of grain yield.