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05 June 1992, Volume 6 Issue 2 Previous Issue    Next Issue
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研究报告
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研究报告

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The Products of Genes Resistant to Rice Blast by Using Some Pairs of Near-Isogenic Lines Huang Danian,Yang Wei,Wang Jinxia,Fan Zaifeng,Zou Qin,He Zuhua,Shen Zongtan 1992, 6(2): 49-52 .  Abstract ( )   PDF (510KB) ( )   With classical genetical methods. we have constructed several sets of near-isogenic lines, which are very similar in their genetic background except in resistant/susceptible genes to rice blast. The patterns of PAGE and IEF gel of isoperoxidase as well as 2-D electrophoresis for each pair of near-isogenic lines showed that both were highly bomogeneity. The results of 2-D electrophoresis of protein from near-isogenic pairs without the inoculation of blast pathogen indicated that the generation of blast disease in rice plants may have a close association with some of its protein subunits in the region of pI 7.5-8.5 and MW 30-45kDa. Therefore, this region may be called as"pathogenesis-related region" (PR-region). It was considerable that the protein variation of the plants at 5 days after inoculation also appeared in this region.

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Varietal Difference in Photosynthetic Response to Different Light Intensity in Rice Yan Jianming,Jiao Demao,Zhu Xiandai,Wang Gongjin,Chen Bingsong,Tong Hongyu 1992, 6(2): 53-56 .  Abstract ( )   PDF (286KB) ( )   To elucidate varietal difference in photosynthetic response to different light intensity in rice, photosynthetic capability and RuBPC activity and PEPC activity in rice leaves were determined by using 14C-tracer techniques under continued high light and low light. The results showed that photosynthetic rate and RuBPC activity in indica-japonica hybrid rice Yayou 2 were inhibited lesser and appeared to be a property of photosynthetic stability as compared with that in indica hybrid rice Shanyou 63. It was worthy of being noted that PEPC activity was induced to increase remarkably under photoinhibitory condition in the rice variety Yayon 2. Meanwhile, photosynthetic performances of indica-japonica hybrid rice and their parents were studied. Photosynthetic characteristics in indica-japonica hybrid rice Yayou 2 based on japonica rice 02428, which is a valuabled germplasm in the breeding of indica-japonica hybrids.

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Effect of Low Temperature of Chlorophyll Fluorescence at 77K of Flag Leaves in Hybrid Rice F1 and Its Parents Li Ping,Wang Yirou,Chen Yizhu,Liu Hongxian 1992, 6(2): 57-62 .  Abstract ( )   PDF (375KB) ( )   Using three hybrid rice combinations Shanyou 63, Qingyouzao and Xiuyou 57 grown in field (natural condition) as material, effect of chilling (5℃) and light (210 μmol m-2s-1 PFD) on chlorophyll fluorescence at 77K of flag leaves in hybrid rice F1 and its parents were investigated. Results showed that the parameters of fluorescence, Fo, Fm and Fv were decreased by chilling treatment. The cold tolerance among three hybrid rice combinations could be reflected from variable fluorescence. The cold tolerance of F1 hybrid rice was between that of male sterile line and restorer line. During chilling under low light Fo, Fm and Fv increased but Fv/Fm and Fv/Fo did not change. It was demonstrated that the chilling treatment with the lower light intensity had no significant effects on the efficiency of the primary conversion of the light energy of PSⅡ and the transport rate of the light energy of PSⅡ as compared with that of under growing condition. So, the photoinhibition was not occurred in the photochemical reaction of photosynthesis. Based on this result, the flag leaves taken from the field under strong light intensity, under 5℃ and 210μmol m-2s-1PFD treatment, light 210 μmol m-2s-1PFD might facilitate the adaptation of rice to chilling so that the degree of injury of photochemical process in leaves was reduced.

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Genetics and Stability of Thermo-sensitive Genic Male Sterile Rice Wu Xiaojin,Yin Huaqi 1992, 6(2): 63-69 .  Abstract ( )   PDF (377KB) ( )   Thermo-sensitive Genic Male Sterile Rice (TGMS) lines Annong S-1, Hengnong S-1 and W6154S were used to study their genetics and stability in fertility transformation. All the three TGMS lines had a stable fertility transformation; and the genes responsible for the fertility of the three TGMS lines might be non-allelic. The fertility of Annong S-1 and Hengnong S-1 was controlled by a couple of recessive genes, the genetic mode of the fertility of W6154S could not be defined according to the segregation ratio of F2 and BF1; W6154S did not have a stable (even) population in fertility, the percentage of stained pollens were different among plants, panicles and spikelets. The expression of genes responsible for fertility of W6154S and Annong S-1 was influenced by the genetic background; the sterile plants selected from the combinations of W6154S still showed fertility segregation.

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Monitoring in Susceptibility of Whitebacked Planthopper and Brown Planthopper to Thirteen Insecticides Mao Lixin,Liang Tianxi 1992, 6(2): 70-76 .  Abstract ( )   PDF (475KB) ( )   Susceptibility levels of whitebacked plathopper (WBPH, Sogatella furcifera Horvath) and brown planthopper (BPH, Nilaparvata lugens Stal) to 13 insecticides were monitored in laboratory by using standard topical application method. The monitoring results during 1987-1991 indicated: (1) Strains of WBPH and BPH were most susceptible to carbofuran, the lowest to malathion. The LD50values fluctuated among years as the two kinds of hoppers were migrant pests. (2) The development of resistance in WBPH population was faster than that of in BPH population. Compared with LD50values of some insecticides of Nagata (1967), WBPH (Zhejiang, 1990) had a 110.56-fold resistance to malathion, 48.90-fold to fenitrothion, and BPH had a 11.61-fold resistance to malathion, 6.11-fold to fenitrothion at the same monitoring method. (3) There was a negative relation between resistance level of BPH population and the local chemical used. (4) There existed a wide variation of toxicity of the different insecticide varieties of the organophosphorous. The toxicity of monocrotophos was more than 10 times as high as that of malathion.

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Screening of the Antagonistic Bacteria for Biocontrol of Rice Sheath Blight (in English) Lin Birun,Wu Shangzhong,Xu Xianming,T W Mew,A M Rosales 1992, 6(2): 77-82 .  Abstract ( )   PDF (292KB) ( )   Bacteria isolated from healthy rice plant, infected rice plant, rhizosphere soils, water in paddy field and sclerotia showed antagonism to Thanatephorus cucumeris (Rhizoctonia solani). Most of the isolates inhibited mycelial growth of pathogen in vitro test. Some of the isolates could suppress the disease and protect the rice from infection in the greenhouse. Some isolates (1 out of 49) could promote rice seedling growth. The relative lesion length of rice sheath blight was significantly correlated with disease incidence (r2=0.33) but not the inhibition zone (r2=0.03) nor detached leaf lesion length (r2=0.12). The seedling dry weight was also not significantly correlated with relative lesion length (r2=0) nor disease incidence (r2=0.01). The isolating and screening way for effective isolates was also supposed.

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Somatic Variability of Buff Pigment Mutants of Rice Blast Fungus (in English) Shen Ying,Zhu Peiliang,Yuan Xiaoping,Hei Leung 1992, 6(2): 83-88 .  Abstract ( )   PDF (170KB) ( )   We produced buff mutants from a field isolate using UV-mutagenesis. Of 13 UV-induced buff mutants tested six were able to cause sporulating. lesions on rice plants. Buff cultures were recovered from lesions on CO 39, IR50 and IR36, suggesting that certain buff mutants have the ability to infect rice without nurmal melanin synthesis. Lesions derived from some buff mutants given conidial cultures with wild type pigment at frequencies ranging from 10% to 100%. White variants were also recovered from lesions caused by buff mutants. Pigment variants did not occur at frequency greater than 10-3-10-4 in plating experiments. Lesions obtained from IR50 coinoculated with a buff mutant and a wild type isolate gave predominantly buff cultures. In one case,a single lesion caused by a buff mutant gave both wild type and buff cultures. These data suggest that somatic changes might occur during interaction with rice plants.

研究简报

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Distorted Segregation of Waxy Gene and Its Characterization in Indica-Japonica Hybrids Xu Yunbi,Shen Zongtan 1992, 6(2): 89-92 .  Abstract ( )   PDF (263KB) ( )   In order to study the segregation distortion of waxy gene, three intersubspecific compatible japonica varieties Xiushui 117, T8340 and 02428, and Taichung 65 and its four isogenic F1-sterile lines were used to cross and backcross with three pairs of waxy and isogenic nonwaxy indica lines Yuanfengzao vs Yuanfengzao Nuo, Guangluai 4 vs Guangluai 4 Nuo and Zhenzhu 19 vs Zhenzhu 19 Nuo. Results indicated that for grains setting on F1 plants and triple cross F1 plants, the segregation of nonwaxy(n) and waxy(w)could be classified into three types, namely, n: w> 3:1, n: w=3:1 and n: w<3:1. Some genetic factor was found to be responsible for the distorted segregation by influencing pollen competition to some extent and its function was independent of F1 sterility gene. Considering that the distorted segregation showed distinct characterizations from the gametophyte genes reported hitherto, the authors postulated that it could be controlled by the interaction between sporophytic and gametophytic genes.

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The Detection of Xanthomonas campestris pv. oryzae with the McAb-ELISA after Multiplication Li Qingxian,Li Shiwen,Gao Jinliang,Hu Guanggan,Zhu Hua,Huang Benli 1992, 6(2): 93-95 .  Abstract ( )   PDF (206KB) ( )   A double antibodies sandwich ELISA with the monoclonal antibody as the second antibody for the rapid detection of Xanthomonas campestris pv. oryzae in rice seeds was developed. The bacterial from husk of the seed samples were shake-cultured in sterile liquid medium for 48 h at 25℃, and followed by ELISA detection. 126 seed samples from Jiangsu and Zhejiang were tested, 93% of seed samples from infected rice were positive.