Archive

28 March 2007, Volume 14 Issue 1 Previous Issue    Next Issue
---
Research Paper
Review or Special Topic
Short Communication


For Selected:

Download Citations EndNote Ris BibTeX

Toggle Thumbnails

Research Paper

Select

Utilization of eui Gene from a Recessive Tall Rice Mutant 02428h in Breeding WANG Cai-lin, ZHAO Ling, ZHU Zhen, ZHANG Ya-dong 2007, 14(1): 1-6 .  Abstract ( )   PDF (97KB) ( )   In order to improve the panicle extrusion of photo- and thermo-sensitive sterile line ‘Pei’ai 64S’ by using elongated uppermost internode (eui) gene of the wide compatibility rice mutant ‘02428h’, a new photo- and thermo-sensitive sterile line ‘P8hS’ characterized with elongated uppermost internode was developed by transferring the eui gene into Pei’ai 64S through three successive backcrossing. Compared with Pei’ai 64S, the plant height of P8hS was 35.6 cm higher resulted from the elongation of the uppermost and the second internodes from the top. The panicle extrusion of Pei’ai 64S was completely improved and positive effects were found on the main economic characters of P8hS and its hybrids by introducing eui gene into Pei’ai 64S.

Select

Analysis of QTLs for Flag Leaf Shape and Its Response to Elevated CO2 in Rice (Oryza sativa) FAN Gui-zhi, DONG Yan-jun, WANG Chun-ming, WAN Jian-min, XIE Hui, XU Chang-liang, ZHU Jian-guo, CAI Qing-sheng 2007, 14(1): 7-12 .  Abstract ( )   PDF (64KB) ( )   To understand the responses of flag leaf shape in rice to elevated CO2 environment and their genetic characteristics, quantitative trait loci (QTLs) for flag leaf shape in rice were mapped onto the molecular marker linkage map of chromosome segment substitution lines (CSSLs) derived from a cross between a japonica variety Asominori and an indica variety IR24 under free air carbon dioxide enrichment (FACE, 200 μmol/mol above current levels) and current CO2 concentration (Ambient, about 370 μmol/mol). Three flag-leaf traits, flag-leaf length (LL), width (LW) and the ratio of LL to LW (RLW), were estimated for each CSSL and their parental varieties. The differences in LL, LW and RLW between parents and in LL and LW within IR24 between FACE and Ambient were significant at 1% level. The continuous distributions and transgressive segregations of LL, LW and RLW were also observed in CSSL population, showing that the three traits were quantitatively inherited under both FACE and Ambient. A total of 16 QTLs for the three traits were detected on chromosomes 1, 2, 3, 4, 6, 8 and 11 with LOD (Log10-likelihood ratio) scores ranging from 3.0 to 6.7. Among them, four QTLs (qLL-6*, qLL-8*, qLW-4*, and qRLW-6*) were commonly detected under both FACE and Ambient. Therefore, based on the different responses to elevated CO2 in comparison with current CO2 level, it can be suggested that the expressions of several QTLs associated with flag-leaf shape in rice could be induced by the high CO2 level.

Select

Relationship Between Coleoptile Length and Drought Resistance and Their QTL Mapping in Rice HU Song-ping, YANG Hua, ZOU Gui-hua, LIU Hong-yan, LIU Guo-lan, MEI Han-wei, CAI Run , LI Ming-shou , LUO Li-jun 2007, 14(1): 13-20 .  Abstract ( )   PDF (86KB) ( )   By using a set of recombinant inbred line (RIL) population involving in 195 lines derived from a cross of Zhenshan 97B (lowland variety) and IRAT109 (upland variety), the correlation analysis between coleoptile length (CL) and drought resistance index (DRI) and their QTL identification were conducted. There existed a significantly positive relationship between CL and DRI with the correlation coefficient of 0.2206** under water stress conditions. Under normal and water stress conditions, a total of eleven and four QTLs for CL and DRI, respectively, were detected on chromosomes 1, 2, 4, 5, 6, 7, 9, 11 and 12 by using a linkage map including 213 SSR markers, which explained 4.84% to 22.65% of phenotypic variance. Chromosomes 1 and 9 possessing the QTLs for DRI harbored simultaneously QTLs for CL, and qCL9 shared the same chromosome location with qDRI9 (RM160-RM215). Comparing the QTLs related to drought resistance in other studies, QTLs for CL and DRI were located in the same or adjacent marker interval as those related to root traits, such as number, dry weight, depth, and length of root. Moreover, sixteen and three pairs of epistatic loci for CL and DRI were found, which accounted for 56.17% and 11.93% of the total variation in CL and DRI, respectively. Key words:

Select

Source and Inheritance of the Within Cultivar Residual Variation Detected in an indica Variety IR64 WU Jian-li , SHI Yong-feng, CHEN Jie, Casiana Vera CRUZ , ZHUANG Jie-yun, Hei LEUNG, ZHENG Kang-le 2007, 14(1): 21-26 .  Abstract ( )   PDF (52KB) ( )   The phenotypically uniform indica variety IR64 was chosen for study of the source and inheritance of within cultivar residual variation using a set of SSR markers. Residual heterogeneity in IR64 was identified on the short arm of chromosome 2 involving at least 5 SSR loci spanning nearly 30 cM. The SSR variations originated from the parental lines of IR64 (IR5657-33-2 / IR2061-465-1-5-5) and were segregating in the selfed bulk seed stock in a Mendelian manner for more than 20 years. This study verified that the within cultivar variations of SSR in a morphologically uniform variety IR64 of a selfing crop came from its parental lines, which has immediate and commercial applications including test of hybrid seed purity, varietal fingerprinting, and curation and propagation of germplasm collections.

Select

Analysis on Factors Affecting Seedling Establishment in Rice LUO Ju, TANG Shao-qing, HU Pei-song, Aleman LOUIS , JIAO Gui-ai, TANG Jian 2007, 14(1): 27-32 .  Abstract ( )   PDF (82KB) ( )   Abstract: Elongations of coleoptile and mesocotyl are related directly to rice seedling establishment in soil and height of plant is related to lodging in rice production. Twelve typical rice cultivars with different lengths of coleoptile and mesocotyl (long, medium and short) were selected by screening the lengths of coleoptile and mesocotyl in 1500 accessions. The seedling establishments of these typical cultivars were compared under the combinations of different sowing depths and flooding durations, and two semi-dwarf varieties (G140, Zhong 96-21) with good seedling establishments and optimum mesocotyl lengths were found. The length of mesocotyl was completely fitted negative binomial distribution and the length of coleoptile was nearly fitted lognormal distribution. Analysis of the relationships among mesocotyl, coleoptile, seeding depth, flooding duration, and their interactions to seedling establishment percentage showed that there existed significant relations among mesocotyl, coleoptile, mesocotyl × coleoptile, seeding depth, flooding duration and mesocotyl × sowing depth in the experiment for seedling establishment.

Select

Relationships of Ethylene Evolution Rate and 1-Aminocylopropane -1-Carboxylic Acid Concentration in Grains during Filling Period with Appearance Quality of Rice YANG Jian-chang, CHANG Er-hua, TANG Cheng, ZHANG Hao, WANG Zhi-qin 2007, 14(1): 33-41 .  Abstract ( )   PDF (437KB) ( )   To elucidate the relationship between ethylene evolution from the grains and the appearance quality of rice, ten different rice genotypes were used to determine the ethylene evolution rate, 1-aminocylopropane-1-carboxylic acid (ACC) concentration in grains during grain filling and the appearance quality of rice, and the effects of chemical regulators on concentrations of ethylene and ACC in the grains during grain filling were also investigated to verify the roles of ethylene in the rice quality formation. The ethylene evolution rates and ACC concentrations in grains during the mid and late grain filling stages were very significantly and positively correlated with chalky kernel percentage and chalkiness. The cultivars with a low ACC concentration in grains exhibited a close amyloplast arrangement and small space between starch granules, whereas those with a high ACC concentration in grains showed a loose arrangement and wide space between the granules. Application of 1 μmol/L ACC to panicles at mid and late grain filling stages significantly loosened amyloplast arrangement and increased chalky kernel percentage, chalky area and chalkiness, and the results were reversed when 1 μmol/L amino-ethoxyvinylglycine, an inhibitor of ACC synthesis enzyme, was applied to panicles. A practice of moderate dry-wet alternate irrigation reduced ethylene evolution and ACC concentration in grains and thereby reduced chalkiness. The results suggested that ethylene and ACC in grains play an important role in the endosperm structure and appearance quality of rice, and the appearance quality would be improved by reducing ethylene evolution and ACC in grains through either variety breeding and selection, or chemical regulations or cultivation techniques.

Select

Effects of Formulated Fertilizer Synergist on Abscisic Acid Accumulation, Proline Content and Photosynthetic Characteristics of Rice under Drought WANG Shao-xian, XIA Shi-tou, PENG Ke-qin, KUANG Feng-chun, CAO Yong, XIAO Lang-tao 2007, 14(1): 42-48 .  Abstract ( )   PDF (55KB) ( )   To investigate the effects of formulated fertilizer synergist on the drought tolerance in rice, pot experiment was conducted to analyze the photosynthetic characteristics and the accumulation of abscisic acid (ABA) and proline in middle-season rice variety Peiliangyou 93. The synergist could improve the net photosynthetic rate, and coordination between the water loss and the CO2 absorption as well as reduce the harmful effect on photosynthetic process under drought conditions. Under drought, the ABA accumulated massively both in roots and leaves, while the ABA content in roots was far higher than that in leaves. The results indicate that synergist could increase the ABA accumulation, but reduce the proline accumulation in rice plant under drought.

Select

Response of Exotic Invasive Weed Alternanthera philoxeroides to Environmental Factors and Its Competition with Rice YU Liu-qing, Yoshiharu FUJII , ZHOU Yong-jun, ZHANG Jian-ping, LU Yong-liang, XUAN Song-nan 2007, 14(1): 49-55 .  Abstract ( )   PDF (57KB) ( )   A greenhouse experiment was conducted to determine the influence of the environmental factors such as low-temperature, drought stress, salt-alkali and flooding on the survival rate, propagation rate, fresh biomass and viability of the Alternanthera philoxeroides and its competitive ability against rice by using bioassay method. A high viability of 84% was found when the stems were treated at 4℃ and then grew under normal conditions, while no viable plant was noted when the stems were treated at -20℃ and grew under normal conditions. Compared to the fresh stem with water content of 93.5%, the survival rate, number of propagated stems and fresh biomass of A. philoxeroides derived from the stems with water content of 30.2% were reduced by 45%, 33% and 74% respectively. The treatments of 0.1% salt-alkaline solution led to loss of viability of A. philoxeroides. The stems of A. philoxeroides could grow in wet soil with different depths of water-layer. The A. philoxeroides at density of 23-180 plants/m2 reduced the rice grain yield by 43-50% at the rice plant density of 100 plants/m2.

Review or Special Topic

Select

Effect of Nitrogen Fertilizer on Herbivores and Its Stimulation to Major Insect Pests in Rice LU Zhong-xian, YU Xiao-ping, Kong-luen HEONG , HU Cui 2007, 14(1): 56-66 .  Abstract ( )   PDF (71KB) ( )   Nitrogen is one of the most important factors in development of herbivore populations. The application of nitrogen fertilizer in plants can normally increase herbivore feeding preference, food consumption, survival, growth, reproduction, and population density, except few examples that nitrogen fertilizer reduces the herbivore performances. In most of the rice growing areas in Asia, the great increases in populations of major insect pests of rice, including planthoppers (Nilaparvata lugens and Sogatella furcifera), leaffolder (Cnaphalocrocis medinalis), and stem borers (Scirpophaga incertulas, Chilo suppressalis, S. innotata, C. polychrysus and Sesamia inferens) were closely related to the long-term excessive application of nitrogen fertilizers. The optimal regime of nitrogen fertilizer in irrigated paddy fields is proposed to improve the fertilizer-nitrogen use efficiency and reduce the environmental pollution.

Short Communication

Select

Relationship Between Canopy Temperature at Flowering Stage and Soil Water Content, Yield Components in Rice ZHANG Wen-zhong, HAN Ya-dong, DU Hong-juan 2007, 14(1): 67-70 .  Abstract ( )   PDF (59KB) ( )   The canopy temperature of rice at the flowering stage and the soil water content were investigated under different soil water treatments (the soil water contents were 24%, 55%, 90% and 175% at the flowering stage). The canopy temperature was lower than air temperature, and the soil water content significantly influenced the canopy temperature. The lower the soil water content, the higher the canopy temperature, the less the accumulative absolute value of canopy-air temperature difference. Moreover, the maximum difference between treatments and CK in the accumulative absolute value of canopy-air temperature difference appeared at 13:00 p.m. in a day, thus, it could be considered as a suitable measuring time. Under the lowest water content treatment, the peak flowering occurred in the first three days (about 70% of panicles flowered), resulting in shortened and lightened panicle of rice. As to the CK and the high water content treatments, the peak flowering appeared in the middle of flowering duration, with longer panicle length and higher panicle weight. Results indicated the lower the soil water content, the less the filled grain number and grain yield.