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10 October 2003, Volume 17 Issue 4 Previous Issue    Next Issue
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研究报告
研究简报
实验技术
综述与专论


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研究报告

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Genetic and Allelic Analysis of New Dwarf Genes in Two Double-Dwarf Germplasms MA Liang-yong ,ZHU Xu-dong ,LI Xi-ming ,YANG Chang-deng ,ZHUANG Jie-Yun ,MIN Shao-kai ,XIA Ying-Wu 2003, 17(4): 291-296 .  Abstract ( )   PDF (210KB) ( )   Genetical analysis of dwarfism in two double-dwarf germplasms indicated that the dwarfism in Qiannong and Te’ai were controlled by two recessive dwarf genes, respectively, of which a common one was allelelic to sd-1 and the others were non-allelic to sd-1. Xinqian’ai and Xinte’ai possessing new semi-dwarf genes sd-q(t) and sd-e(t)from Qiannong and Te’ai, respectively, were selected.Allelism test between sd-q(t)and other genes conferring dwarfism or semi-dwarfism in rice indicated that sd-q(t) was non-allelic to d-29, d-32, d-59, sd-g, sd-6 and d-1X . Xinqian’ai carrying the new semi-dwarf gene sd-q(t) showed to have promising characteristics on agro nomic traits such as grain number per panicle, 1000-grain weight and seed setting rate, suggesting that sd-q(t) might be utilized in rice breeding in rep lacement of sd-1 gene.

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Genotypic Identification of the S-b Locus in the Ind ica-Compatible Japonica Lines of Rice (Oryza sativa) DING Xiao-hua,ZHANG Ze-min,ZENG Rui-zhen,LI Wen-tao,ZHANG Gui-quan 2003, 17(4): 297-301 .  Abstract ( )   PDF (2580KB) ( )   S-b is one of the hybrid sterility loci between indica and japonica cultivars in rice. The genotype of Taichung 65 (T65) and Guanglu’ai 4 (GLA 4) at the locus is Sj/Sj and Si/Si, respectively. Four indica-compati ble japonica lines (ICJLs), G2416-3, G2417-2-1, G2605 and G3004-4 were cros sed with testers, T65 and GLA 4, and their S-b locus genotypes were identified. The segregation of PCR-based molecular markers linked tightly with S-b locus in F2 population showed that G2416-3 and G2417-2-1 possessed Si/Si genotype, while G2605 and G3004-4 contained genotype Sn/Sn. Comparison of genetic effect among the alleles at S-b locus in four ICJLs showed no significant difference between the Si genes in G241 6-3 and G2417-2-1, and between the Sn genes in G2605 and G3004-4, but significant difference between the Si and Sn genes.

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Analysis of Resistance to Rice Sheath Blight for Transgenic Lines of Rice LI Ai-hong ,XU Xin -ping ,DAI Zheng-yuan ,CHEN Zong-xiang ,LI Bao-jian ,ZHANG Hong-xi ,PAN Xue-biao 2003, 17(4): 302-306 .  Abstract ( )   PDF (191KB) ( )   Forty-one homozygous rice lines transferred with chitinase gene (RC24) and β-1,3-glucanse gene(β-1,3-Glu)were selected to study on their resistance to sheath blight. The resistance of transgenic lines had significant differences, and according to t he result of cluster analysis, they could be divided into resistant, moderately resistant, moderately susceptible and susceptible types, but 92.1% of them belonged to the type of moderately resistant or moderately susceptible. For diffe rent resistant or susceptible type lines, rice sheath blight resistance was significant correlated with the chitinase activity of transgenic lines except resistant type lines, in which enzyme activity coded by target gene was lower than that of moderately resistant type. The chitinase activity of transgenic lines at different time after inoculation or different parts of the same plant were alike, which suggested that the expression of chitinase gene was constitutive. Check varieties’chitinase activity would chang e at different time after inoculation and reach a peak at sometime, but it had n o differences at different parts of the same plant.

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Analysis on Resistant Spectrum to Rice Blast in Transgenic Rice Lines with Chitinase Gene and β-1,3-Glucanase Gene XU Ming-hui ,LI Cheng-yun ,LI Jin-bin ,TAN Xue-lin ,TIAN Ying-chuan ,CHEN Zheng-hua ,TANG Zuo-shun ,TIAN Wen-zhong 2003, 17(4): 307-310 .  Abstract ( )   PDF (156KB) ( )   Four transgenic rice lines harboring binary chitinase gene and β-1,3-glucanase gene were challenged in the greenhouse by inoculating 33 isolates belonging to 24 races of Magnaporthe grisea collected from Yunnan Province. Results showed that transgenic rice lines exhibited high resistance to 20 isolates which could infect the receptor cultivar Nan 29 and almost all of the isolates which could not infect the receptor cultivar. It indicated that introduction of binary chitinase gene and β-1,3-glucanase gene into restorer line of Dian-type hybrid rice enhanced resistance to blast, and the transgenic rice lines possessed wide-spectrum resistance against various rice blast races. Disease score of leaf blast were 0-1 degree and disease incidence of neck blast were 0.3%-10.23% in the transgenic lines under the blast nursery, showing resistance to the disease enhanced in transgenic line. It suggested that these transgenic rice lines could be available for breeding resistant variety.

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Resistance to Bacterial Leaf Blight in Somaclonal Mutant HX-3 at Cell Level GAO Dong-ying ,HUANG Xue-qing ,LIU Yong-feng ,SUN Li-hua ,CHEN Zhi-yi ,LIU Ai-min 2003, 17(4): 311-314 .  Abstract ( )   PDF (156KB) ( )   The interaction between rice host and its pathogen Xanthomonas oryzae pv. oryzae (Xoo) at cell level was studied using a resistant somaclonal mutant HX-3 and its donor Minghui 63. After inoculation of Xoo strain Zhe 173(Chinese pathotype Ⅳ), the activity of superoxide dismutase(SOD) and peroxidase(POD) in the callus of Minghui 63 was increased dramatically, and the active oxygen was produced at a higher rate; Meanwhile, the callus grew slowly with the reduction of protein content. However, the activity of SOD and POD, the product ion rate of active oxygen and the fresh weight in HX-3 callus varied little after inoculation. It could be proposed that there were great differences between the resistance of HX-3 and Mighui 63 at cell level. There was no difference in resistance to bacterial leaf blight in HX-3 between the plant and the callus.

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Analysis of QTLs for Resistance to Rice Bacterial Blight YU Yan-chun ,TENG Sheng ,ZENG Da-li ,DONG Guo-jun ,QIAN Qian ,HUANG Da-nian ,ZHU Li-huang 2003, 17(4): 315-318 .  Abstract ( )   PDF (145KB) ( )   A japonica/indica double haploid(DH) population, derived from Zhaiyeqing 8 and Jingxi 17, was used to analyze QTLs for resistance to rice bacterial blight (BBR). Both the parents and DH population did not carry any major gene and the parents were moderately susceptible to strain of Xanthomonas oryzae pv. oryzae(Xoo), Zhe 9612. Four QTLs (qBBR-3, qBBR-4, qBBR-5, and qBBR-6) were detected for BBR on chromosome 3, 4, 5 and 6, respectively. qBBR-3 and qBBR-4 showed additive effect, and qBBR-5 and qBBR-6 negative, the total effect of four QTLs was 38.6%. The variance analysis and significance test showed that the BBR effect of the rice lines with four QTLs was highly significant, and the resistance to Xoo strain could be attained by pyramiding minor genes.

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Transfer of Starch Viscosity Characteristics Between Subspecies (Variety) and Variety in Rice WU Dian-xing,DUAN Zhi-ying,SHU Qing-yao,XIA Ying-wu 2003, 17(4): 319-322 .  Abstract ( )   PDF (164KB) ( )   The progenies derived from crosses, using early indica rice Zhefu 504 as female parent, three types of representative good grain quality varieties, i.e. single cropping indica rice IR64, javanica rice Lemont, and japonica rice Xiushui 11 as the donors, were investigated to explore the potentiality in developing good grain quality early indica rice through transfer of starch viscosity characteristics between subspecies (variety) and variety. The lines with low apparent amylose content (AAC) derived from three crosses had the similar starch viscosity characteristics, but the lines with intermediate AAC were obviously different. Rich variations in RVA profile were observed in the progenies derived from Zhefu 504/IR64, and it was easy to screen the lines with the same starch viscosity characteristics as IR64 did. Only a few lines with the similar starch viscosity characteristics as Lemont did were screened from the Zhefu 504/Lemont-derived progenies, however, it failed to detect the lines with better starch viscosity characteristics like Xiushui 11 from the Zhefu 504/Xiushui 11-derived progenies.

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Research on the Methods for Transforming BADH Gene into Rice LU De-zhao ,ZHU Shui-jin ,QIAN Qian ,WANG Hui-zhong ,YAN Mei-xian ,HUANG Da-nian 2003, 17(4): 323-327 .  Abstract ( )   PDF (1142KB) ( )   The transformation effects of BADH gene (encoding betaine aldehyde dehydrogenase) into rice by particle bombarment and Agrobacterium tumefaciens mediated were compared in transgenic plant number, transformation efficiency, rate of PCR positive plantlets, foreign gene copies and their expression activity, and seed setting rate of T0 generation. Results showed that transformation efficiency and rate of PCR positive plantlets by Agrobacterium tumefaciens mediated were higher than those by particle bombardment method. Moreover, the performance in seed setting rate of T0 generation and some other agronomic traits of transgenic rice obtained from Agrobacterium tumefaciens mediated gene transfer system were better compared with particle bombarment methodology.

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Difference of RVA Profile Among Different Early Indica Rice Varieties and Effect of Temperature at Grain Filling Stage on it WANG Feng ,CHENG Fang-min ,ZHONG Lian-jin ,SUN Zong-xiu 2003, 17(4): 328-332 .  Abstract ( )   PDF (197KB) ( )   Using rapid visco analyzer(RVA),the starch viscosity properties of ten early indica rice varieties with different taste types and their relation with temperature condition at grain filling stage were analyzed. Results indicated that the taste of early indica rice varieties was closely associated with their starch viscosity properties. In general, the early indica rice varieties with superior taste had higher breakdown, lower setback and consistence. On the contrary, the ones with inferior taste had lower breakdown, higher setback and consistence. The differences in peak viscosity, holding strength and final viscosity among varieties with different taste were not significant; Effect of temperature treatments at filling stage on the starch viscosity properties was more closely related to setback and consistence, rather than the breakdown. Compared with high temperature treatment, higher final viscosity, setback and consistence could be found for the proper temperature treatment, it was suggested to be an important physical-chemical criterion for its better taste when some early indica rice varieties was cultivated in late season.

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Analysis of Factors on Outcrossing Seed-Setting Obstacles in Photo-Thermo Sensitive Genic Male Sterile Rice CHEN Xiong-hui,WAN Bang-hui,PENG Hai-feng,LU Yan-peng,LIANG Ke-qin,ZHAO Jing 2003, 17(4): 333-338 .  Abstract ( )   PDF (205KB) ( )   Using photo-thermo sensitive genic male sterile lines (PTGMS) Pei′ai 64S, W7 415S, W6154S, N26S, Annong S, Nongken 58S, 7001S, and 5008S as female parents, a nd conventional indica rice 8258, and U89 as male parents, affecting factors for outcrossing seed-setting were analyzed. Results showed that PTGMS had outcros sing-seed-setting obstacles affected by inheritance and environment at varyi ng degree, environment temperature was the main factor, the sensitive time was at the early grain filling stage for outcrossing seed-setting. It existed sig nificant differences in the sensitive stage, the length of sensitive stage, the sensitive level and the effective level of outcrossing seed-setting obstacles a ffected by environment temperature among different PTGMS.

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Stablility of Seed Setting Rate for a Two-Line Hybrid Rice Liangyoupeijiu in Associated with Temperature LU Chuan-gen,ZONG Shou-yu,ZHAO Ling,WANG Cai-lin,SUN Yong-hua,ZOU Jiang-shi 2003, 17(4): 339-342 .  Abstract ( )   PDF (147KB) ( )   In comparison with an indica hybrid rice Shanyou 63 (CK), Liangyoupeijiu, a two-line indica hybrid rice, showed the seed setting rate of 75.2%-77.2% which was lower by 4.3%-7.5% than that of CK, and approxima te values of grain yield and its variance as planting in southern China in 1999 -2000. Sowing during 5-25th, May in Nanjing (32°3′N, 118°48′E), China, Liangyoupeijiu headed before 4th, September, showed seed setting rate of 75%-90%, and grain yield over 1 kg/m2. Its heading date would be late as 17-21st, September, and seed setting rate would be lowed by 10%-15% in comparison with a suitable sowing date if its sowing date be delayed as 14-15th, June. When flowering took place within an average daily temperature range from 13.7-28.5℃, spikelet fertility (SP) of rice was increased by 1.9%-10.7%, for each degree rise of temperature. The suitable (SP≥90%) and safe (SP≥75%) temperatures at flowering stage were 26.5℃ and 22.9℃, respectively. To get a high and stable seed setting rate for cultivating Liangyoupeijiu, areas being south of 34°N would be suitable, and the average daily temperature during heading stage would be at 26-28℃.

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Effects of Rice Ridge Cultivation on Grain Yield and Quality and Its Physiological and Ecological Mechanisms ZHANG Xiu-fu,WANG Dan-ying,SHAO Guo-sheng 2003, 17(4): 343-348 .  Abstract ( )   PDF (238KB) ( )   With the indica hybrid rice combination Xieyou 9308 and japonica cultivar Bing 98110 as material, the physiological and ecological mechanisms of ridge-cultivated rice were studied. Daily temperature difference (especially at 5-10 cm soil depth) and oxidation-reduction electric potential(5 cm soil depth) were higher under ridge-cultivated condition compared with conventional cultivated condition (rice grew in submerged field). Ridge cultiv ation hastened rice tillering, increased leaf area index, accumulated more dry matter, and produced larger amount of roots in upper soil at filling stage. The plant length, panicle length, percentage of active tillers of ridge cultivated rice were lower than those of conventional cultivated rice, and the panicles per area, seed setting rate, 1000-grain weight conversely. There was no significant difference between the two cultivated methods in chlorophyll content and photosynthetic rate at tillering or full heading stage, SOD and MDA content at late grain filling stages. Yield between ridge cultivated and conventional cultivated rice was significant for Xieyou 9308 but not significant for Bing 98110. The milling, appearance traits of grain were improved under ridge cultivation condition.

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Influence of Soil Drought Stress on Leaf Rolling Index in Different Rice Varieties JIN Qian-yu ,OUYANG You-nan ,YU Sheng-miao ,XU De-hai ,ZHANG Guo-ping 2003, 17(4): 349-354 .  Abstract ( )   PDF (232KB) ( )   The influence of soil drought stress on leaf rolling index (LRI) and its relationship with stomatal conductance (SC), transpiration rate (TR), net photosynthetic rate (Pn) and water use efficiency (WUE) were investigated by using 13 rice ( Oryza sativa L.) varieties differing in drought resistance under the condit ion of artificially-controlled soil water. The drought stress in soil was initiated at effective active tillering stage and ended at booting stage by re-irrig ating. Results showed that there were obvious differences among rice varieties in the initial increasing date, increasing rate and maximum value of LRI. Thirteen rice varieties may be classified into three categories, i.e. sensitive ( e.g. Zhonghan 1), intermediate (e.g. Handao 8) and insensitive (e.g. I APAR 9 ), according to the development of LRI in response to soil drought stress. The LRI increased with the soil water stress for all varieties, but there was dramatic difference among varieties in the relationships between LRI and SC, TR, Pn a nd WUE. With the increase of every one scale in LRI, SC in Zhonghan 1, Handao 8 and IAPAR 9 decreased by 0.26, 0.20 and 0.17 mm/s, respectively, and TR decreased by 0.86, 0.66 and 0.49 mmol/(m2 ·s), respectively. The LRI resulting in substantial reduction in Pn was much smaller in Zhonghan 1 than that in IAPAR 9 . It also showed that the moderate LRI increased WUE, and the effect of LRI on WUE could be attributed to the change of both Pn and TR for Zhonghan 1, but for IAPAR, only the change of TR was significantly related.

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Effects of Different Irrigation Patterns on Physiological Characteristics of Root and Photosynthetic Traits of Flag Leaf after Flowering Stage in Hybrid Rice ZENG Xiang ,LI Yang-sheng ,XIE Xiao-li ,XIAO Guo-ying ,LIAO Jiang-lin 2003, 17(4): 355-359 .  Abstract ( )   PDF (219KB) ( )   The physiological characteristics of root and flag leaf in two hybrid rice, Honglianyou 6 and Liangyou 1193, after flowering stage under different irrigation patterns were studied. Root density and activity were higher under controlled damp irrigation than those of submerged irrigation. Chlorophyll contents in flag leaf under controlled damp irrigation were not different at flowering stage, but distinctly higher at mature stage compared with that under submerged irrigation. Net photosynthetic rate of flag leaf under controlled damp irrigation also significantly higher than that of submerged irrigation at reproductive stage. Compared with submerged irrigation, two hybrid rice combinations had higher community growth rate(CGR) and relative growth rate(RGR), and obtained higher grain yield under controlled damp irrigation. The higher yield might result from enhancement of the dry matter accumulation favorable to the grain development at reproductive stage under controlled damp irrigation.

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Threshold Population Sizes of Bacillus subtilis B5423-R to Suppress the Occurrence of Rice Sheath Blight LI Xiang-min ,HU Bai-shi ,XU Zhi-gang ,MEW T.W. 2003, 17(4): 360-364 .  Abstract ( )   PDF (198KB) ( )   The mechanism of Bacillus subtilis B5423 to suppress the occurrence of rice sheath blight is mainly by means of antibiotics produced by B5423. Under field conditions, the experiment of B5423-R(marker strain of B5423, a Rifampicin-resistant mutant ) to suppress vertical spread of sheath blight was conducted by inoculating R. solani and spraying B5423-R in different methods (including spraying times, and spraying intervals). Successive 3-4 times spraying with an interval of one day made the population sizes of B5423-R on rice stems be higher than 1×106 cfu/g within 6-7 days, and significantly reduced relative lesion height (RLH) of rice sheath blight. On the other hand, successive 3- 4 times spraying with an interval of four days made B5423-R on rice stems fluctuate from 1×106 to 1×105 cfu/g within 15 days, and not cause any significant reduction of RLH of rice sheath blight in 25 days. The above results revealed that the population threshold of B5423-R to suppress rice sheath blight should be higher than 1×106 cfu/g during the early infection of R. solani (within 6-7 days).

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Research on Effect of Temperature on Nutrient Release of Paddy Soil by Using Ion-Exchange Resin Capsules ZHANG Qi-chun,WANG Guang-huo 2003, 17(4): 365-368 .  Abstract ( )   PDF (179KB) ( )   Nutrients (N, P, K, Ca, and Mg) release from paddy soil were studied under different temperatures(15℃, 25℃, 35℃ ) by using UNIBEST(the universal bioavailabi lity environment/test) ion-exchange resin method. Results showed that the rele ase of N, P significantly increased with temperature increased. During seven weeks incubation, N accumulative extraction at 25℃ and 35℃ were 91% and 189% more than that at 15℃, respectively. The P accumulative extraction at the same period at 25℃ and 35℃ were 131% and 393% more than that at 15℃, respectively. Effect of temperature on the release of K, Ca, and Mg in soil was relatively small. The dynamics of soil nutrient release was fit to equation RAQ(i,t) =atb (a and b are the constants, RAQ means resin adsorption quantity, t means incubation time).

研究简报

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Chlorophyll Contents and Net Photosynthetic Rates of T-DNA Inserted Rice Mutant Population LIN Yu-qiong,LIU Song,FU Ya-pin,YU Yong-hong,HU Guo-cheng,SI Hua-min,SUN Zong-xiu 2003, 17(4): 369-372 .  Abstract ( )   PDF (176KB) ( )   Twenty-one lines with phenotype variation were screened from T-DNA inserted population of rice (Oryza sativa L. subsp. japonica cv. Zhonghua 11), chlorophyll content and net photosynthetic rate were m easured at booting stage. There were obvious differences in chlorophyll content among lines, two lines with low content of chlorophyll b were found. Linear relationships existed between the contents of chlorophyll a, chlorophyll b and ch lorophyll (a+b) respectively. Leaf color was related to the content of chlorophyll. Usually, lines with dark green leaves had higher chlorophyll contents and those with light green leaves had lower contents, while the relation to net photosynthetic rate was complicated. The net photosynthetic rate of all lines was lower than that of the control. It was also found that the net photosynthetic rate of several dwarf lines was very low.The role of these mutants on plant physiology and rice functional genomics research were discussed.

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SSR Analysis and Soluble Protein Content in Leaf of Rice Mutants Induced by High Pressure HE Xiu-ying ,XU Shi-ping ,LIAO Yao-ping ,MAO Xing-xue ,WENG Ke-nan ,CHEN Zhao-ming ,CHEN Yue-han ,XIAO Wan-sheng 2003, 17(4): 373-375 .  Abstract ( )   PDF (1088KB) ( )   Rice variety Yuexiangzhan and its mutants induced by high pressure, were studied by using microsatellite marker and soluble protein content analysi s. Results indicated that 11 of the 88 microsatellite primer pairs showed polymorphism. The polymorphic frequency was 3.4%-11.3% between mutants and Yuexiangzhan. The polymorphic markers were randomly located on rice chromosomes. The more similar the plant type of the mutants looked like their original variety(Yuexiangzhan), the less polymorphic loci were obtained. In addition, content of soluble protein in leaves of mutant was significantly lower than that in the original variety.

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Improvement of Shedding Habit of Restorer Line for Super Hybrid Rice Xieyou 9308 SHEN Sheng-quan,WU Dian-xing,SHU Qing-yao,XIA Ying-wu 2003, 17(4): 376-378 .  Abstract ( )   PDF (116KB) ( )   To solve the easy shedding habit of super hybrid rice Xieyou 9308, the dry seeds of restorer T9308 was treated by gamma irradiation, and one elite mutant M930 8 with difficult shedding habit was obtained. Except for the shedding habit, no significant differences in the major agronomic traits, grain quality, and disease resistance were found between the mutant M9308 and the original parent T9308 and their F1 hybrids derived from Xieqingzao A with them. Genetic analys is indicated that the difficult shedding habit of mutant M9308 was controlled by a single recessive gene.

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Effects of Long-term Ultradry Storage on Viability and Vigor of Different Kinds of Rice Seeds HU Wei-min,HU Jin,SONG Wen-jian,DUAN Xian-ming 2003, 17(4): 379-382 .  Abstract ( )   PDF (153KB) ( )   Three kinds of rice seeds (Oryza sativa L.)were ultradryly treated by usin g an approach of silica gel drying, and then stored for nine years under room temperature and airtight condition. Seed germination parameters and POD and SOD ac tivities were investigated. Results showed that japonica rice seeds (Xiushui 37 ) were not suitable to store for long-term under room temperature. While indic a rice seeds (Zhe 733) and hybrid rice seeds(Xieyou 46, Shanyou 63) could be stored very long in ultradry condition. The viability and vigor of indica rice see ds with 2.7% moisture content and hybrid ones with 5% were the highest, and their germination rate was about 80%. The storability of hybrid rice seeds were high er compared with indica rice seeds and their germination rate only reduced by 8 %-9%. Both viability and vigor of indica and hybrid rice seeds were significantl y reduced when moisture contents were too low or too high. Positive correlations were observed between POD activity and the viability or vigor of the seeds.

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Tolerance of Eight Species of Echinochloa to Pretilachlor WANG Qing-ya ,QIAO Li-ya ,WEI Jie-gang ,DONG Li-yao ,LI Yang-han 2003, 17(4): 383-386 .  Abstract ( )   PDF (152KB) ( )   The seeds of eight species and varieties of barnyar dgrass were treated with pretilachlor. Differences in bud length, leaf cells length, coleoptile cells length, and α-amylases activities of barnyardgrass after the herbicide treatment were found among eight species and varieties of barnyardgrass. Control percentage of the herbicide to Echinochloa crusgalli var. mitis was the lowest, and E. colonum was the highest among the tested barnyardgrass. It seemed th at the different species and varieties of barnyardgrass have various tolerance to the pretilachlor.

实验技术

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A Rapid Method for Screening Storable Rice Cultivars by Carotene Bleaching SHEN Wen-biao ,YU Wei-wei ,WANG Ren ,JIANG Ling ,ZHAI Hu-qu ,CHENG Shi-hua ,WAN Jian-min 2003, 17(4): 387-389 .  Abstract ( )   PDF (142KB) ( )   Based on co-oxidation secondary reaction functio n of lipoxygenase-3(LOX-3) in rice embryo, a rapid method for detecting the lack of LOX-3 in rice embryos by carotene bleaching for only three hours was developed and optimized. The method is simple, inexpensive and suitable to rapid screening storable rice cultivars compared with monoclonal antibody technique and indide-starch method. It was deduced that LOX-1 and LOX-2 in rice embryos probably displayed less or no co-oxidation activities under normal air condition in comparison with that of LOX-3. The perspective of carotene bleaching method on the usage in breeding for storable rice cultivars and related-cloning research was also discussed.

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Preliminary Study on Inoculation Method of Rice False Smut and Its Effect ZHANG Jun-cheng ,ZHANG Bing-xin ,CHEN Zhi-yi ,LIU Yong-feng ,LU Fan 2003, 17(4): 390-392 .  Abstract ( )   PDF (109KB) ( )   Artificial inoculation of Ustilaginoidea virens (Cooke.) Tak. cultured in vitro was made by injecting at nightfall during booting stage of rice . The mixture of hyphae broken and conidia of the pathogen could cause serious disease of false smut. The maximum percentage of infected panicle(PIP) was 100 %, the maximum number of spore balls(NSB) of a panicle was 106, and the maximum disease index(DI) was 85.5. Disease severities caused by different strains, and disease severities of different rice materials caused by the pathogen were different; and there was obvious correlationship between DI and PIP, and between DI and average NSB of a panicle. It seemed that there existed specific interaction between strain and variety.

综述与专论

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Review of the Research on the Classification of the Genus Oryza ZHANG Nai-qun ,LI Yun-xian ,ZHU Li-li ,HE Guang-cun 2003, 17(4): 393-397 .  Abstract ( )   PDF (204KB) ( )   The genus Oryza L. is one of the important plant groups in the grass family, which includes more than 20 species and is distributed in tropics and subtropics of the world. During about 250 years since the first description of the genus Oryza by Linnaeus, great changes have taken place in the genus in terms of the number of species and taxonomic status. The existing problems were discussed, and the suggestion on the taxonomy of the genus Oryza was given.