Seed and pollen transmission of asparagus virus 2

The spread of peach rosette and decline dlsease (PRD) was studied in two clingstone peach orchards, located 24 km apart in the Goulburn Valley of Victoria. Over 11 years the incidence of diseased trees in an orchard of cv. Golden Queen increased from 0.9 to 91.5%, while in an orchard of cv. Pullar's Cling the proportion of diseased trees rose from 1.5 to 29.6% over 5 years. The apparent infection rates were identical in both orchards over the first 5 years of the two epidemics.In both orchards, a significantly higher proportion of healthy trees growing adjacent to previously diseased trees became infected in subsequent seasons. This pattern of spread of the disease is discussed in relation to pollen transmission of the viruses and the foraging habits of bees. The spread of PRD was reduced by 29.4% over 2 years by the grubbing of all visibly diseased trees before flowering in a planting of cv. Golden Queen. Removing the flowers from diseased trees at the 'pink bud' stage also reduced the rate of spread of the disease by 13.8% in 1 year. Removing newly diseased limbs at the crotch of the tree within 4 weeks of flowering, however, did not prevent the spread of the disease into the rest of the tree.

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Pollen Transmission of Asparagus virus 2 (AV-2) May Facilitate Mixed Infection by Two AV-2 Isolates in Asparagus Plants

Phytopathology ◽

10.1094/phyto-12-13-0348-r ◽

2014 ◽

Vol 104 (9) ◽

pp. 1001-1006 ◽

Cited By ~ 5

Author(s):

Ryusuke Kawamura ◽

Hanako Shimura ◽

Tomofumi Mochizuki ◽

Satoshi T. Ohki ◽

Chikara Masuta

Keyword(s):

Mixed Infection ◽

Nicotiana Benthamiana ◽

Pollen Grains ◽

Mixed Infections ◽

Sequence Analyses ◽

Tobacco Plants ◽

Pollen Transmission ◽

Infected Tobacco ◽

Immunohistochemical Analyses

Asparagus virus 2 (AV-2) is a member of the genus Ilarvirus and thought to induce the asparagus decline syndrome. AV-2 is known to be transmitted by seed, and the possibility of pollen transmission was proposed 25 years ago but not verified. In AV-2 sequence analyses, we have unexpectedly found mixed infection by two distinct AV-2 isolates in two asparagus plants. Because mixed infections by two related viruses are normally prevented by cross protection, we suspected that pollen transmission of AV-2 is involved in mixed infection. Immunohistochemical analyses and in situ hybridization using AV-2-infected tobacco plants revealed that AV-2 was localized in the meristem and associated with pollen grains. To experimentally produce a mixed infection via pollen transmission, two Nicotiana benthamiana plants that were infected with each of two AV-2 isolates were crossed. Derived cleaved-amplified polymorphic sequence analysis identified each AV-2 isolate in the progeny seedlings, suggesting that pollen transmission could indeed result in a mixed infection, at least in N. benthamiana.

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Studies on seed and pollen transmission of Alfalfa Mosaic, Cucumber Mosaic and Bean Yellow Mosaic Viruses in cultivars and accesions of annual Medicago species

Australian Journal of Agricultural Research ◽

10.1071/ar9950153 ◽

1995 ◽

Vol 46 (1) ◽

pp. 153 ◽

Cited By ~ 10

Author(s):

W Pathipanowat ◽

RAC Jones ◽

K Sivasithamparam

Keyword(s):

Transmission Rate ◽

Seed Transmission ◽

Transmission Rates ◽

Pollen Transmission ◽

Immature Seeds ◽

Annual Medicago ◽

Carry Over ◽

Transmission Studies ◽

Medicago Species ◽

Seed Coats

Seed and pollen transmission of alfalfa mosaic (AMV), cucumber mosaic (CMV) and bean yellow mosaic (BYMV) viruses was investigated in annual medic species (Medicago spp.). For seed transmission studies with AMV, graft inoculation was used to establish early infection and maximize possible transmission rates to seedlings via seed, but with CMV and BYMV aphid and/or graft inoculation was used. For pollen transmission studies, pollen taken from virus-infected plants was used to pollinate healthy plants, the seed collected and seedlings tested. The rates of AMV isolate OUI-2 transmission to seedlings through seed produced on infected plants ranged from 6 to 53% for commercial cultivars and from 7 to 65% for accessions. Accession DZA 3181.1.1 of M. sphaerocarpos had the highest overall AMV transmission rate. Only two cultivars, cvv. Borung and Hannaford of M. truncatula, and accession SA 4268 of M. orbicularis, had transmission rates of less than 10%. The rates of CMV transmission to seedlings via seed produced on infected plants of the cultivars and accessions tested were 0.3 to 13%, the greatest being found in M. polymorpha cv. Serena, but 6 out of 11 had no detectable transmission. The rates of BYMV transmission to seedlings via seed of the cultivars and accessions tested were 0.3 to 1%, but in 12 out of 15 none was detected. AMV isolate OUI-2 was transmitted to 52% of seedlings via seed produced on healthy M. polymorpha cv. Circle Valley plants pollinated from infected plants. In contrast, no transmission to seedlings by either graft-inoculation or pollination of M. polymorpha plants was detected with a second AMV isolate, OUI-1, which appeared to have lost its ablilty to be seed transmitted. No CMV or BYMV transmission to seedlings via pollination of healthy plants with pollen from infected plants was detected in M. polymorpha cvv. Circle Valley or Santiago. When empty immature pods, and dissected seed coats and embryos from immature seeds produced on AMV-infected plants of M. polymorpha were tested, AMV isolates OUI-I and OUI-2 were detected in all pods and seed coats, but only in 59% of embryos with isolate OUI-2 and in none with isolate OUI-1. CMV was detected in 12% of embryos tested from immature seeds produced on CMV-infected M. polymorpha cv. Serena plants. Transmission of all three viruses through seed, and of AMV through pollen, is cause for concern in annual medic breeding and evaluation programs. Moreover, carry-over outside the growing season in medic pastures is possible through seed with all three viruses.

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Investigation onCacao swollen shoot virus(CSSV) pollen transmission through cross-pollination

Plant Pathology ◽

10.1111/j.1365-3059.2012.02640.x ◽

2012 ◽

Vol 62 (2) ◽

pp. 421-427 ◽

Cited By ~ 8

Author(s):

G. A. Ameyaw ◽

A. Wetten ◽

H. Dzahini-Obiatey ◽

O. Domfeh ◽

J. Allainguillaume

Keyword(s):

Pollen Transmission ◽

Cross Pollination

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Some ultrastructural aspects of the pollen transmission of barley stripe mosaic virus in barley

Canadian Journal of Botany ◽

10.1139/b86-111 ◽

1986 ◽

Vol 64 (4) ◽

pp. 853-858 ◽

Cited By ~ 7

Author(s):

Ronald H. Brlansky ◽

Thomas W. Carroll ◽

Susan K. Zaske

Keyword(s):

Pollen Tube ◽

Mosaic Virus ◽

Developmental Stages ◽

Ovary Wall ◽

Barley Stripe Mosaic Virus ◽

Thin Sections ◽

Virus Particles ◽

Pollen Transmission ◽

Transmission Electron ◽

Particle Form

To study the pollen transmission of barley stripe mosaic virus (BSMV) in barley with the transmission electron microscope, ultrathin sections of ovaries of pollinated pistils were examined. Healthy pistils were cross-pollinated with virus-infected pollen and collected at various intervals of time after pollination. When thin sections of the ovaries were viewed, virus particles were detected in specific sporophytic and gametophytic cells during critical developmental stages of pollination, fertilization, and embryogenesis. Before fertilization, BSMV particles were seen in the pollen tube between the integument and ovary wall, and in pollen tube discharge within the degenerating synergid. During and after fertilization, virus particles were found not only in the pollen tube and its discharge but also in the zygote, endosperm, persistent synergid, and nucellus. During embryogenesis, BSMV particles were very evident in the embryo, integument, and ovary wall. Some particles were scattered throughout the cell cytoplasm, while others were in mono- or multi-layer aggregates within the cytoplasm. Many particles were associated with spindle or cytoplasmic microtubules or with abnormal plastids. The prevalence of virus particles in the cells associated with sexual reproduction suggests that the nucleoprotein particle form of the virus plays some role in the pollen transmission of BSMV in barley.

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THE CYTOGENETIC LOCALIZATION OF THE ALCOHOL DEHYDROGENASE-1 LOCUS IN MAIZE

Genetics ◽

10.1093/genetics/94.3.687 ◽

1980 ◽

Vol 94 (3) ◽

pp. 687-700

Author(s):

James A Birchler

Keyword(s):

Alcohol Dehydrogenase ◽

Genetic Markers ◽

Meiotic Segregation ◽

Reciprocal Translocations ◽

Pollen Transmission ◽

Low Level ◽

Chromosome I ◽

Alcohol Dehydrogenase 1

ABSTRACT The alcohol dehydrogenase-I (Adh) locus in maize has been positioned relative to thirteen reciprocal translocations that have breakpoints in the long arm of chromosome I (1L). The methods of GOPINATH and BURNHAM (1956) to produce interstitial segmental trisomy with overlapping translocations and of RAKHA and ROBERTSON (1970) to produce compound B-A translocations were coupled with the co-dominant nature of the ADH isozymes to allow the cytological placement. The results of several crosses are consistent with Adh being in the region of 0.80-0.90 of 1L.—The duplication that results from the overlap of translocations 1-3 (5267) and 2-3 (5242) and that includes Adh was studied with respect to meiotic segregation and pollen transmission. When heterozygous with normal chromosomes, a low level of recombination within the duplicated regions is detectable and the duplication and normals are recovered with equal frequencies through the female. In the pollen, the hyperploid grains cannot compete equally with the euploids in achieving fertilization.—The use of co-dominant heteromultimeric isozymes as genetic markers for the development of a series of interstitial segmental trisomics in maize is discussed.

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