Soybean preference for Bradyrhizobium japonicum for modulation

Abstract

Caldwell and Vest (1968) planted soybeans (Glycine max L. Merr.) with various genotypes at Beltsville, USA, without inoculating them with Bradyrhizobium japonicum, and showed that soybeans preferred certain serotypes of rhizobial strains for nodulation. Recently, the authors have reported that soybeans carrying nodulation-conditioning genes preferred appropriate strains showing specific behavior for nodulation (Ishizuka et al. 1991). For instance, nodulation of soybean cv. Hardee which carries the nodulation-conditioning genes, Rj ₂ and Rj ₃, does not occur with B. japonicum USDA122, USDA33, Is-1, etc. Nodulation of cv. Hill which carries the Rj ₄ gene, does not occur with B. japonicum USDA61, Is-21, etc. while A62-2 which carries a recessive gene rj ₁, does not nodulate with almost any of the strains of B. japonicum. Therefore, the B. japonicum strains can be classified into three nodulation types based on the compatibility with these Rj-cultivars, that is, type A strains which effectively nodulated both Rj ₂ Rj ₃-cultivars and Rj ₄-ones, type B strains which did not nodulate the Rj ₂ Rj ₃-cultivars and type C strains which did not nodulate the Rj ₄-cultivars. When the nodulation types of the isolates from nodules of field-grown soybeans were examined, it was suggested that the Rj ₂ Rj ₃-cultivars and Rj ₄-cultivars preferred the type C and type B strains, respectively (Ishizuka et al. 1991).     

Volatile 1-octen-3-ol induces a defensive response in <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis>

1-Octen-3-ol is a major volatile metabolite produced by mold fungi. When Arabidopsis plants were treated with 1-octen-3-ol, some defense genes that are turned on by wounding or ethylene/jasmonic acid signaling were induced. The treatment also enhanced resistance of the plant against Botrytis cinerea. When the induction of defense genes with 1-octen-3-ol was compared with that by volatile methyl jasmonate (MeJA) and methyl salicylate treatments, the induction pattern was similar to that caused by MeJA. Thus, Arabidopsis seems to recognize 1-octen-3-ol and consequently activates its defense response.     

4个抗黄萎病海岛棉染色体片段导入系黄萎病抗性配合力分析

以海岛棉7124抗黄萎病染色体片段导入系CSIL-035、CSIL-096、CSIL-108和CSIL-155为父本,新陆早33号、新陆早40号、新陆早42号、新陆早45号为母本,采用不完全双列杂交法配制16个组合,进行海岛棉染色体片段导入系黄萎病抗性配合力研究。研究结果表明,导入系CSIL-035、CSIL-096、CSIL-108和CSIL-155的发病率、病情指数、相对病指均具有较高的负向一般配合力(General combining ability,GCA)效应,均达到了显著水平。新陆早33号分别与导入系CSIL-035、CSIL-096、CSIL-108和CSIL-155配置的组合,其发病率、病情指数、相对病指特殊配合力(Specialcombiningability,SCA)效应为负值,均达到了显著或极显著水平。组合新陆早40号×CSIL-035和新陆早42号×CSIL-155的病情指数、相对病指SCA效应为负值,对黄萎病的抗性具有正向的促进作用。     

Effects of crown length on indole acetic acid (IAA) amounts in cambial region tissues in lower and upper trunks of sugi cultivars (Cryptomeria japonica) in September

Indole acetic acid (IAA) was believed to be an important regulator in xylem formation in conifers. However, few studies have been done on the endogenous amount of IAA in cambial region tissues in sugi (Cryptomeria japonica) trees. In this study, we report the IAA amounts in the lower and upper trunk of mature sugi cultivars (Kumotoshi, Yaichi and Obiaka) in September, and the effects of growth traits on the IAA amounts. The effect of height position (lower or upper trunk) on IAA amounts was found to be larger than that of genetic variation (Kumotoshi, Yaichi or Obiaka) by two-way ANOVA. There was no significant interaction effect (genetic variation × height position). The IAA amounts of all trees varied from 3 to 42 ng/cm² at the lower trunk and 9 to 47 ng/cm² at the upper trunk. Crown length and distance from crown base had significant positive and negative effects on IAA amounts in the trunk of sugi cultivars, respectively. Distance from crown base had a larger effect on IAA amounts than crown length. In Yaichi, taller trees had larger IAA amounts at both the lower and upper trunk.     

Age and growth of yellowstriped butterfish, <Emphasis Type="Italic">Labracoglossa argentiventris</Emphasis>, around Izu Oshima Island

ABSTRACT:   Age and growth of the yellowstriped butterfish, Labracoglossa argentiventris , around Izu Oshima Island were studied using a total of 1450 fish. Age was determined by counting the edge of the opaque zones as a ring mark on sectioned sagittal otoliths. Formation of the first ring was observed during spring or summer, corresponding to 1.5 years after hatching. Thereafter, one ring was formed each year in the same season as the previous year. The growth of the butterfish was rapid until 2 years of age. The maximum likelihood method was applied to the age and length data for estimating parameters in von Bertalanffy, Gompertz, and Logistic growth models. The selected model, based on the Akaike Information Criterion, was the von Bertalanffy growth model, which indicated differential asymptotic length and variance by sex.     

Texture analysis of stereograms of diffuse-porous hardwood: identification of wood species used in Tripitaka Koreana

Tripitaka Koreana is a collection of over 80,000 Buddhist texts carved on wooden blocks. In this study, we investigated whether six hardwood species used as blocks could be recognized by image recognition. An image data set comprising stereograms in transverse section was acquired at 10×?magnification. After auto-rotation, cropping, and filtering processes, the data set was analyzed by an image recognition system, which comprised a gray-level co-occurrence matrix method for feature extraction and a weighted neighbor distance algorithm for classification. The estimated accuracy obtained by leave-one-out cross-validation was up to 100% after optimizing the pretreatments and parameters, thereby indicating that the proposed system may be useful for the non-destructive analysis of all wooden carvings. We also examined the specific anatomical features represented by textures in the images. Many of the texture features were apparently related to the density of vessels, and others were associated with the ray intervals. However, some anatomical features that are helpful for visual inspection were ignored by the proposed system despite its perfect accuracy. In addition to the high analytical accuracy of this system, a deeper understanding of the relationships between the calculated and actual features is essential for the further development of automated recognition.     

农业政策性金融服务乡村振兴的可行性分析

探讨了新时代数字农业政策性金融服务体系的建设和推进,以促进经济高质量发展。研究指出,建设该体系对于将发展红利通过金融手段普及给广大人民群众至关重要。此外,本文还探讨了数字农业政策性金融服务与乡村振兴、城镇化建设之间的关联,强调了提高服务质量和效率的策略。在保障服务质量方面,本文提出了建立透明严格的监管制度的必要性,以应对金融风险。最后,为推进地区间数字农业政策性金融服务的融合交流,促进金融服务与经济发展的协调,呼吁加强区域合作和支持中西部地区的发展,为新时代数字农业政策性金融服务体系的发展提供参考。     

Genomic in situ hybridization (GISH) analysis of intergeneric hybrids in Colchicaceae

Some intergeneric hybrids produced by the crosses among several colchicaceous ornamentals, Gloriosa superba ??Lutea?? (2n = 2x = 22), G. ??Marron Gold?? (2n = 4x = 44), G. ??Verschild?? (2n = 7x = 77), Littonia modesta Hook. (2n = 2x = 22), and Sandersonia aurantiaca Hook. (2n = 2x = 24), were subjected to genomic in situ hybridization (GISH) analysis in order to clarify their genome constitutions. Chromosome preparation was made from root tip cells of L. modesta × G. superba ??Lutea??, L. modesta × S. aurantiaca, S. aurantiaca × G. superba ??Lutea??, L. modesta × G. ??Marron Gold??, S. aurantiaca × G. ??Marron Gold?? and G. ??Verschild?? × S. aurantiaca. Total DNA of one parent was labeled with digoxigenin or biotin and used as probe, and chromosomes were counterstained with 4??-6-diamidono-2-phenylindole (DAPI). For all the nine intergeneric hybrids, chromosomes from each parent could be clearly distinguished by GISH analysis. Thus GISH analysis is a powerful tool for identifying the genome constitution of intergeneric hybrids in colchicaceous ornamentals. The results obtained by GISH analysis study may be important for further progress in breeding of colchicaceous ornamentals.     

Effects of symbiosis with Rhizobium fredii on transport of fixed nitrogen in the xylem of soybean plants

An experiment was conducted to identify the main nitrogenous compound transported in the xylem sap of soybean plants nodulated with Rhizobium fredii. Soybean (Glycine max L. Merr.) cultivars, wild type Bragg (nod⁺, fix⁺) and its nitrate tolerant, hypernodulating mutant ntsll16 (nod⁺⁺, fix⁺) were used for this experiment. These soybean plants were inoculated with a slowgrowing rhizobium, Bradyrhizobium japonicum USDAllO or fast-growing rhizobia consisting of a mixture of R. fredii USDA191, USDA193, and USDA-194 and grown in a phytotron under natural light and controlled temperature conditions. Xylem sap was collected from Bragg and ntsll16 plants at the flowering and pod elongation stages. Acetylene reduction activity per plant or per nodule weight was not different between soybean lines and inoculums. The composition of the nitrogenous compounds in the xylem sap was compared between the symbionts, with B. japonicum and R. fredii. At the flowering stage, ureide-N and amide-N accounted for 53 to 70% and 20 to 27% respectively of the total N in the sap collected from the plants inoculated either with B. japonicum or R. fredii. At the pod elongation stage, ureide-N and amide-N accounted for 74 to 85%, and 7 to 19% of total sap N. With the growth of the soybean plants, the ratio of ureide-N in the xylem sap increased. These results suggest that in the case of wild soybean and the hypernodulating mutant line nodulated by R. fredii, ureide is transported as the main nitrogenous compound of fixed nitrogen in the xylem sap in the same way as in plants nodulated with B. japonicum.