The occurrence of Indian peanut clump, a soil-borne virus disease of groundnuts (Arachis hypogaea) in India

A disease characterised by severely stunted plants with small dark green leaves was found in groundnut (Arachis hypogaea) in sandy soils in Punjab State, India. The disease occurred in patches in the field and reappeared in the same positions in succeeding groundnut crops. Plants infected early did not produce mature pods. Seeds sown in soil collected from infected fields produced plants with typical disease symptoms. Phaseolus vulgaris cv. Local and Chenopodium quinoa were found to be good diagnostic hosts. The disease was shown to be caused by a rod-shaped virus c. 24 nm in diameter with predominant particle lengths of c. 249 and 184 nm when stained in uranyl acetate. The virus, named Indian peanut clump virus (IPCV), resembled peanut clump virus (PCV) reported from W. Africa in symptomatology on groundnuts, particle morphology and soil-borne nature. However, it is not serologically related to two W. African PCV isolates tested, or to tobacco rattle (PRN and CAM strains) or pea early browning virus (Dutch isolate) in microprecipitin, enzyme linked immunosorbent assay and immunosorbent electron microscopy tests

Unmasking motherhood : a poststructuralist study of motherhood and its meanings for women

The intention of the following paper is to explore from a poststructuralist perspective the reasons why women choose to have children and the consequences resulting from this choice. Interviews were conducted with women who were mothers, and a selection of contemporary feminist literature, some related to motherhood and some to poststructuralist feminist theory, reviewed, in order to develop an understanding of the subject positions available to women in the discourses of motherhood. Two paradoxical and contradictory discourses of motherhood emerge, which are described in the concluding chapter of the paper

Turnip mosaic potyvirus probably first spread to Eurasian brassica crops from wild orchids about 1000 years ago

Turnip mosaic potyvirus (TuMV) is probably the most widespread and damaging virus that infects cultivated brassicas worldwide. Previous work has indicated that the virus originated in western Eurasia, with all of its closest relatives being viruses of monocotyledonous plants. Here we report that we have identified a sister lineage of TuMV-like potyviruses (TuMV-OM) from European orchids. The isolates of TuMV-OM form a monophyletic sister lineage to the brassica-infecting TuMVs (TuMV-BIs), and are nested within a clade of monocotyledon-infecting viruses. Extensive host-range tests showed that all of the TuMV-OMs are biologically similar to, but distinct from, TuMV-BIs and do not readily infect brassicas. We conclude that it is more likely that TuMV evolved from a TuMV-OM-like ancestor than the reverse. We did Bayesian coalescent analyses using a combination of novel and published sequence data from four TuMV genes [helper component-proteinase protein (HC-Pro), protein 3(P3), nuclear inclusion b protein (NIb), and coat protein (CP)]. Three genes (HC-Pro, P3, and NIb), but not the CP gene, gave results indicating that the TuMV-BI viruses diverged from TuMV-OMs around 1000 years ago. Only 150 years later, the four lineages of the present global population of TuMV-BIs diverged from one another. These dates are congruent with historical records of the spread of agriculture in Western Europe. From about 1200 years ago, there was a warming of the climate, and agriculture and the human population of the region greatly increased. Farming replaced woodlands, fostering viruses and aphid vectors that could invade the crops, which included several brassica cultivars and weeds. Later, starting 500 years ago, inter-continental maritime trade probably spread the TuMV-BIs to the remainder of the world

Critical structure factor in Ising systems

We perform a large-scale Monte Carlo simulation of the three-dimensional Ising model on simple cubic lattices of size L^3 with L=128 and 256. We determine the corresponding structure factor (Fourier transform of the two-point function) and compare it with several approximations and with experimental results. We also compute the turbidity as a function of the momentum of the incoming radiation, focusing in particular on the deviations from the Ornstein-Zernicke expression of Puglielli and Ford.Comment: 16 page

Tobacco rattle virus genome alterations in the Hosta hybrid ‘Green Fountain’ and other plants: reassortments, recombinations and deletions

Tobacco rattle virus from a Hosta hybrid contained one RNA1 (Ho-1) and two RNA2 species (Ho-2a, Ho-2b). Whereas Ho-1 resembles TRV Al RNA1 from Alstroemerias, Ho-2a and Ho-2b resemble TRV TpO1 RNA2 from a potato field. Ho-2a has a complete RNA2-specific sequence, whereas that of Ho2-b carries a large deletion. The short RNA1-related 3' end of Ho-2a is distinct from that of Ho-1, whereas the longer one of Ho-2b is identical to that of Ho-1. TRV RNA2 molecules may apparently become associated with different TRV RNA1 molecules, from which they can acquire 3'ends of various lengths while often losing large portions of their RNA2-specific sequences.Biophysical Structural Chemistr

Biological characteristics of tomato mild mottle virus A potyvirus isolated from tomato and thorn apple in Ethiopia

Two isolates of the virus 246/94 and 277/94, acquired from thorn apple (Datura stramonium   ) and tomato (Lycopersicon lycopersicum   (L.) Karst. Ex. Farw., syn. esculentum), respectively, were characterised biologically and serologically and compared with a local isolate of Potato virus Y (PVY) isolated from tomato and other potyviruses and isolates infecting vegetables. Both isolates of TMMV infected only 16 of 28 plant species inoculated mechanically and induced indistinguishable symptoms. The most susceptible hosts were D. metel, D. stramonium   and Nicotiana glutinosa   L. However, these isolates differed from the PVY isolate by infecting Datura spp.   and Solanum demissum   L., while the PVY isolate infected Chenopodium quinoa   Wild and Capsicum annuum   L. Isolate 277/94 was transmitted non-persistently by the aphid, Myzus persicae Sulz. from diseased tomato to virus-free D. stramonium, D. metel L., N. glutinosa   and tomato plants and from these back to virus-free test plants of each species. Purified particles of isolate 277/94 contained a single protein species with a molecular weight of 39 kDa. Furthermore, in double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) antiserum to isolate 277/94 reacted strongly with a Yemeni isolate of TMMV (Y90/7), but did not react with any other potyvirus. This clearly shows that the Yemeni and Ethiopian isolates of TMMV are similar serologically

Biological characteristics of tomato mild mottle potyvirus isolated from tomato and thorn apple in Ethiopia

Two isolates of the virus 246/94 and 277/94, acquired from thorn apple (Datura stramonium) and tomato (Lycopersicon lycopersicum (L.) Karst. Ex. Farw., syn. esculentum), respectively, were characterised biologically and serologically and compared with a local isolate of Potato virus Y (PVY) isolated from tomato and other potyviruses and isolates infecting vegetables. Both isolates of TMMV infected only 16 of 28 plant species inoculated mechanically and induced indistinguishable symptoms. The most susceptible hosts were D. metel, D. stramonium and Nicotiana glutinosa L. However, these isolates differed from the PVY isolate by infecting Datura spp. and Solanum demissum L., while the PVY isolate infected Chenopodium quinoa Wild and Capsicum annuum L. Isolate 277/94 was transmitted non-persistently by the aphid, Myzus persicae Sulz. from diseased tomato to virus-free D. stramonium, D. metel L., N. glutinosa and tomato plants and from these back to virus-free test plants of each species. Purified particles of isolate 277/94 contained a single protein species with a molecular weight of 39 kDa. Furthermore, in double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) antiserum to isolate 277/94 reacted strongly with a Yemeni isolate of TMMV (Y90/7), but did not react with any other potyvirus. This clearly shows that the Yemeni and Ethiopian isolates of TMMV are similar serologically. RÉSUMÉ Datura stramonium et Nicandra physalodes Gaertn en Ethiopie. Deux formes du virus 246/94 et 277/94, ont ete obtenue respectivement partir du Datura stramonium et de tomates (Lycopersicon lycopersicum (L.) Karst. Ex. Farw., syn. esculentum) infectees. Leurs compositions biologique et sérologique ont été identifiées et comparées avec: d'autres potyvirus, un virus présent dans les pommes de terre locales Y (PVY) et isolé à partir des tomates, et d'autres formes de virus présents dans des légumes contaminés. Les deux formes du virus TMMV ont contaminé 16 des 28 plants inoculés mécaniquement, provoquant des symptômes similaires. Les plants où le virus s'est cependant le mieux développé sont: le D. metel, le D. stramonium et le Nicotiana glutinosa L. Cependant, ces deux formes different du virus PVY dans la mesure où ils ont contaminé le Datura spp. et le Solanum demissum L, alors que le PVY a contaminé le Chepodium quinoa Wild et le Capsicum annuum L. Le virus 277/94 a été transmis de manière non persistante par l' Aphid, Myzus persicae Sulz. Des tomates contaminées vers du D. stramonium, D. metel L., N. glutinosa et des plants de tomate saints, puis de ces plants infectés vers d'autres plans tests saints de chaque espèce. Des particules purifiées du virus (277/94) contiennent une seule espèce de protéine avec une molécule pesont 39 kDa. De plus, une enzyme sandwich d'anti-corps immunosorbent assay (DAS-ELISA) antiserum permettant d'isoler le 277/94, a réagi fortement avec la forme Yéménite du virus TMMV (Y90/7). Ceci démontre clairement que les formes Yéménite et éthiopienne du virus TMMV sont très proches d'un point de vue sérologique. (African Crop Science Journal 2001 9(3): 517-526