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10 October 1999, Volume 13 Issue 4 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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Isolation and Cytological investigation on Two Tetrasomics in Rice Yu Hengxiu,Cheng Zhukuan,Li Xin,Gu Minghong 1999, 13(4): 193-196 .  Abstract ( )   PDF (367KB) ( )   From the progenies of triplo-9 and triplo-11 of an indica rice variety, Zhongxian 3037, two morphological variants were selected. Cytological investigation was conducted on the variants. Three types of synaptic configuration, i. e., 12 +2 I, 11 1 +1 N and 11 1 +l +1 I, were detected at both pachytene and diakinesis in meiosis in pollen mother cells.Moteover,26 separated chromosomes were detected in anaphase I. It is shown that both of the two variants are tetrasomicswith a pair of extra chromosomes of chromosome 9 and chromosome 11, respectively, according to their pachytene karyotype.

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Genetic Expression for Quality Traits of Rice Grain in Japonica Hybrids Li Xin,Mo Huidong,Wang Anmin,Xu Chengwu,Zhu Yihua,Yu Hengxiu 1999, 13(4): 197-204 .  Abstract ( )   PDF (645KB) ( )   A statistical method recently proposed by Mo et al. for analysing the inheritance of seed trait in p + q + 2pq mating design was used to investigate the genetic expression of nine quality traits in japonica hybrid rice. The parents were p= 4 maintainers and q = 7 restorers. The results showed: (1)The expression of brown, milled, and head rice rates (BRR, MRR, HRR), grain length (GL), grain width (GW), and chalkiness score (CS) in hybrids was subject to the diploid maternal genotypes and no genetic segregation occurred among F2 grains born on F1 plant. However, very significant segregation was found among F2 grains in gelatinization temperature (GT), amylose content (AC), and gel consistency (GC). This indicated that the inheritance of GT, AC, and GC was mainly controlled under the endosperm genotype. (2) The additive variation was principal component in all traits except AC. But the variance due to F2 grain segregation had a considerable share intotal genetic variance in AC, GT, and GC traits. This suggested further that the three traits were mainly controlled by triploid endosperm genotyps. (3) The result of reciprocals showed there was a significant cytoplasmic effect in all nine qualitytraits, but their shares were not large, only from 2. 49% (GT) to 29. 3% (MRR) and concentrating from 2% to 5%. Although variation was also observed among traits or crosses.

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Varietal Difference of Heat Tolerance at Grain Filling Stage and its Relationship to Photosynthetic Characteristics and Endogenous Polyamine of Flag Leaf in Rice Huang Yingjin,Luo Yongfeng,Huang Xingzuo,Rao Zhiming,Liu Yibai 1999, 13(4): 205-210 .  Abstract ( )   PDF (548KB) ( )   The evaluation of heat tolerance at grain filling stage was studied on 65 early season rice varieties from differentgene sources ,and the physiological reaction around high temperature stress at grain filling stage was compared between the varieties with much difference in heat tolerance. The results indicated that the stress index of unfilled grain rate, filled grainweight, head rice rate, chalkiness and protein content could be regarded as the five indexes of heat tolerance for field directevaluation at grain filling stage in rice. There was much difference in heat tolerance among the different varieties according tothe comprehensive evaluation of heat tolerance by subordinate function value. Thus several varieties with high heat tolerancewere screened. The photosynthetic ability of rice can be affected seriously by high temperature stress,but the decrease extentof flag leaf photosynthetic rate of varieties with high heat tolerance is significantly lower. The recovery level is also higher after removing stress. The changing trend of chlorophyll content, RuBPc activity and endogenous polyamine content is thesame,which is the important physiological characteristics of heat tolerance in rice.

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Comparison of Carbon Nutrition Between Effective Tillers and ineffective Tillers in Rice Jiang Pengyan,Hong Xiaofu,Xu Zhifu,Ni Zhuru 1999, 13(4): 211-216 .  Abstract ( )   PDF (475KB) ( )   A pot experiment was carried out to study the character of carbon nutrition of effective and ineffective tiller byusing rice variety Zhe 8619 as materials. When the leaf-index of main stem was in the range of from 84. 5% to 91. 6%, the dryweight of ineffective culms almost did not increase in this period. As a result the largest critical dry weight of the ineffectivetillers was taken as the critical individual dry weight of effective tillers and the period was called dry weight stagnating increase stage. The dry weight stagnating increase stage could be taken as the index for direct diagnosis of turn stage from ineffective tillers to effective tillers. The results also showed the carbon nutrition characteristics of ineffective tillers: The abilityof ineffective tillers accepting nutrition was no less than that of other tillers in the early growing stage I Since the tillers stagnated growth the total amount of 14C-glucose accumulated in the tillers was distinctly lower because the assimilation productwhich main stems exported to tillers was reduced. During the turn stage, the photosynthetic ability distinctly became less andthe accumulation of photosynthetic products was reduced. When the ineffective tillers were dying there were a few assimilation products exporting from ineffective tillers. The poorer the ineffective tillers were, the less the assimilation products exported.

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Regulating the inter-Grain Apical Dominance of Rice by GA3 and PP333 Wang Xi,Tao Longxing,Huang Xiaolin,Yu Meiyu 1999, 13(4): 217-222 .  Abstract ( )   PDF (473KB) ( )   The regulation of GA3 and PP333 applied at initial heading stage on rice grain filling characteristics was studied in some hybrid rice combinations and conventional rice varieties. The results indicated that the panicle apical dominance could be enhanced by application of GA3 and inhibited by PP333. GA3 treatment could increase 1000-grain weight with low seed-setting rate, eventually decrease the grain yield of hybrid rice. PP333 application at initial heading stage could increase grain yield both in hybrid rice and in conventional varieties. High concentration of GA3(>30 mg/L) and PP333 (>50 mg/L) treatment could have negative effects on grain yield. The two-component plant growth substance, Lilibao (meaning every grain will be filled), were formulated.

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Residual Effects of the Paddy-Upland Yearly Rotation Wang Renmin,Chen Jinxin,Ding Yuanshu 1999, 13(4): 223-228 .  Abstract ( )   PDF (484KB) ( )   After a 6-year (1987-1993) long-term experiment with barley-rice-rice (BRR, CK) and barley-corn-rice(BCR) cropping system, the effect of different cropping system on the yield and growth of the succeeding crops and its mechanism were studied in 1993-1994 in Zhejiang Province. The results showed that the yields of the succeeding crops late-rice andbarley after barley-corn-rice cropping system were significantly higher than that after barley-rice-rice cropping system. There was no significant difference in the yield of the 3rd succeeding crop early rice between two cropping system. It was more beneficial to the increasing of the crop yield and the improving of the soil fertility that two cropping system was rotated each otherevery year in production. The reason for those were mainly that the soil physical and chemical characteristics were more im. proved under BCR than under BRR, so that the hydrolytic N, available P, and available K content of paddy soil under BCRwere higher than those under BRR, the root oxidative power of the succeeding crop late rice was increased under BCR. All ofthose accelerate the growth of the succeeding crops and the absorption of nutrients. Then the effective panicle number, seedsetting rate and filled grain number of the succeeding crop late rice were increased and the effective panicle number and 1000 grain weight of the succeeding crop barley were increased. The result also showed that the fertilizer application could reducethe residual effect of the paddy-upland yearly rotation.

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Virulent Shift in Populations of Nilaparvata lugens (Homptera: Delphacidae) Wang Guirong,Lai Fengxiang,Fu Qiang,Zhang Zhitao,Guo Lanfang 1999, 13(4): 229-232 .  Abstract ( )   PDF (319KB) ( )   The shift of virulence in ASD7 of rice brown planthopper from field and laboratory was studied. The results showed that the field populations with different virulence, of which the virulence was determined by the amount of honeydew excreted on ASD7, can shift to ASD7 population after rearing four generations on ASD7 respectively. On the contrary, the virulence of ASD7 population became weak gradually during rearing on TN1. After seven generations rearing on TN1, ASD7 population degenerated into TN1 population. It is suggested that virulence of rice brown planthopper was variable and the character of variety resistant or susceptible to insect was the exterior factor of virulent shift.

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Microbial Diversity of Nonpathogenic Pseudomonads and Related Bacteria from Rice Seeds in Zhejiang Province of China and Luzon Island of the Philippines (in English) Xie Guanlin,Wu Zhixian,Yu Xuefang,T W Mew 1999, 13(4): 233-238 .  Abstract ( )   PDF (453KB) ( )   One hundred and sixteen seed samples from Zhejiang Province of China and 129 from Luzon Island of the Philippines were studied for species diversity of Pseudomonads and related bacteria during 1993 - 1998. Over 1200 bacterial isolatesfrom Zhejiang Province and 2300 from Luzon Island were picked and identified by bacteriology, pathogenicity and numeric taxonomy method (Biolog). The fluorescent bacteria population in unit of rice seed from Luzon island was significantly higher thanthat from Zhejiang Province. Sixteen species or types of Pseudomonas and two related species were identified, about half of which were not recorded from rice seeds before. Five hundreds and three nonpathogenic Pseudomonads and related bacterial isolates from Zhejiang Province and Luzon Island were tested for antagonists against Rhizoctonia solani, Sarocladium oryzae, and Acidovorax avenae subsp. avenae. About 12% and 17% of the total isolates were antagonistic against one or more of the pathogens in Zhejiang Province and Luzon Island respectively.

综述与专论

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On Genetic Basis of Heterosis Breeding incorporated with Elite Pure Lines in Rice Li Renhua,Yang Zhenyu,Luo Xiaohe,Wang Xiangkun 1999, 13(4): 239-241 .  Abstract ( )   PDF (271KB) ( )   The progress in genetic basis of heterosis were reviewed. Multi-phasal classification was made to the main female parent, Pei'ai 64S, which is widely used in commercial two-line-system hybrid rice breeding. A viewpoint of favorable genes and favorable genic interactions has been proposed to explain the genetic basis of heterosis in which elite pure lines are incorporated.

研究简报

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Breeding of Resistance to Brown Planthopper (Nilaparvata lugens) in Indica Hybrid Rice Wang Jianjun,Yu Xiaoping,Lu Zhongxian,Tao Linyong,Shi Shouyun,Dong Wenqi 1999, 13(4): 242-244 .  Abstract ( )   PDF (239KB) ( )   The characters of resistance to brown planthopper (Nilaparvata lugens) of 80 restorers in indica hybrid ricewere evaluated. It was found that 30 restorers express medium- or higher-grade resistance. Twelve of them show super to ASD7 in durable resistance. These materials, 0-3 degree of resistant grade and durable resistance >7 d, were divided into first degree of resistant materials. After testing heterosis, assessing apparent rice quality, evaluating resistance to rice leaf blight and rice blast, two new restorers were selected. One restorer, Aihong/Tai 1059, expressed medium grade of resistanceto rice leaf blight and rice blast and brown planthopper. The yield of its hybrid with Xieqingzao A increased 12. 9% than thatof CK Shanyou 10. Another, LS-2/Milyang 46, possessed such characteristics as high resistance to brown planthopper and rice blight, medium resistance to rice leaf blight, and excellent apparent rice quality.

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A Further Study on the Effects of Copper in Rice Callus Culture (in English) Yang Yuesheng,Zheng Guichao,Jian Yuyu 1999, 13(4): 245-247 .  Abstract ( )   PDF (254KB) ( )   Calli of an indica rice cultivar Qiuguiai 11 were used as material for a further study on the effects of copper in calli cultures. Supplement of copper to a medium containing 2,4-D and proline had little effect on the proliferation rate of the calli, however, upon transfer to the plant regeneration medium, these calli would regenerate significantly more number of plants. On the other hand, supplement of copper to a medium containing proline, BA and NAA would significantly stimulate or suppressthe proliferation of the calli depending on the amount of copper supplemented. Nevertheless, all these calli, no matter the proliferation of which had been stimulated or suppressed by the copper, were able to regenerate more number of plants with higher quality on plant regeneration medium.

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Special Functions of Sorbitol on Rice Somatic Cell Culture Huang Huijun,Huang Daoqiang 1999, 13(4): 248-250 .  Abstract ( )   PDF (238KB) ( )   The effects of sorbitol and mannitol as carbon source on callus induction, plantlet regeneration and haploid chromosome doubling in diploid and haploid young panicle culture of indica rice line TC90 were studied. The results showed that 2% or 4% sorbitol as medium carbon source could efficiently maintain explants alive at least for 25 days, and plantlet regeneration frequency reached 52. 6% and 90. 0% respectively, and haploid doubling rate reached as high as 30. 5%. On the contrary, the explants did not produce any callus, became pale, shrunk and died out after being cultured seven days when 2%or 4% mannitol used as carbon source.

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Photosynthetic Character of Greenable Albino Mutant Line of Rice during Greening Period Weng Xiaoyan,Lu Qing,Mao Weihua,Jiang De'an 1999, 13(4): 251-253 .  Abstract ( )   PDF (227KB) ( )   A greenable albino mutant line of rice W25 and its original line 2177S were used as tested materials. The result showed that lower chlorophyll and protein content were found in leaves of W25 at the albino stage. The content of chlorophyll in leaves increased and got the same level as that of its parent line at the 30th day during the greening period. The content of protein and Rubisco also significantly increased, Rubisco content and activity were higher than those of parent line at the 30th day during greening period, the photosynthetic rate was close to that of parent line at the 18th day during greening period.

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Biological Diversity of Plants on Ridge of Paddy Yu Liuqing,Lu Yongliang,M Nemoto,N Shimizu,Wang Mingyao,Xu Qing 1999, 13(4): 254-256 .  Abstract ( )   PDF (287KB) ( )   Plant species on ridge of paddy at Yushanwu where rice fields were irrigated with spotless water were more than at Chengbei where rice fields were irrigated with water polluted by industrial waste. In the same type of plant community, Yushanwu provided significantly higher total important value [ Iv(t) ] of plant species on ridge of paddy than Chengbei did. The index of biological diversity (H') between two villages were given with the similar trends. The various type of plant community showed the different data of biological diversity. Dominant community of short-stalked plants offered the great advantage of plant species number, Iv(t) and H' compared with the dominant community of high-stalked plants and dominant community of exotic plants. Attention must be paid to the control of an exotic plant Alternanthera philoxeroides, limit ofdominant community of high-stalked plants, as well as protection of dominant community of short-stalked plants.