Diagnosis, occurrence and seed transmission studies of viruses infecting fourCentrosemaspecies in Nigeria

2007 ◽  
Vol 47 (4) ◽  
pp. 244-252 ◽  
Author(s):  
OO Odedara ◽  
J d'A Hughes ◽  
EI Ayo-John
Keyword(s):  
Seed Transmission ◽  
Transmission Studies

Seed Transmission Studies of Xanthomonas oryzae in Rice

1975 ◽  
Vol 65 (6) ◽  
pp. 663 ◽  
Author(s):  
H. E. Kauffman
Keyword(s):  
Seed Transmission ◽  
Xanthomonas Oryzae ◽  
Transmission Studies

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

1995 ◽  
Vol 46 (1) ◽  
pp. 153 ◽  
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.

scholarly journals Detection of Rhynchosporium secalis in barley seeds from Argentina through polymerase chain reaction technique

2007 ◽  
Vol 32 (5) ◽  
pp. 415-418 ◽  
Author(s):  
Melina Ocampo Ríos ◽  
Paula Fernández ◽  
Marcelo Carmona
Keyword(s):  
Polymerase Chain Reaction ◽  
Seed Transmission ◽  
Rhynchosporium Secalis ◽  
Chain Reaction ◽  
Necrotrophic Pathogen ◽  
Slow Growth Rate ◽  
Polymerase Chain ◽  
Transmission Studies ◽  
Barley Genotypes ◽  
Important Disease

Leaf scald of barley caused by Rhynchosporium secalis is an important disease in Argentina. The fungus is a necrotrophic pathogen which survives in stubble, seeds and weeds. Isolation of R. secalis from seeds on artificial media usually has not been successful due to the slow growth rate of the pathogen and strong inhibition by contaminants. The objective in this work was to detect R. secalis in different genotypes of barley seeds in Argentina using the polymerase chain reaction (PCR)-based diagnostic assay. Four barley genotypes were tested in 2004: Quilmes Ayelén, Quilmes Alfa, Barke and Maltería Pampa 1004. The previously described RS8 and RS9 primers were used for the detection of R. secalis in barley seeds. A 264-bp single band was obtained for each cultivar showing the presence of R. secalis. The use of specific primers was efficient in the detection of R. secalis in barley seeds in Argentina and could be used for routine diagnosis, epidemiology and seed transmission studies. This is the first report on the detection of R. secalis in barley seeds in Argentina.

scholarly journals First Report of Colletotrichum gloeosporioides f. sp. manihotis, Cause of Cassava Anthracnose Disease, Being Seed-borne and Seed-Transmitted in Cassava

Plant Disease ◽  
1997 ◽  
Vol 81 (6) ◽  
pp. 695-695 ◽  
Author(s):  
C. N. Fokunang ◽  
T. Ikotun ◽  
A. G. O. Dixon ◽  
C. N. Akem
Keyword(s):  
Colletotrichum Gloeosporioides ◽  
Seedling Emergence ◽  
Canopy Temperature ◽  
Seed Transmission ◽  
Significant Loss ◽  
Crop Failure ◽  
Manihot Esculenta Crantz ◽  
First Report ◽  
Anthracnose Disease ◽  
Transmission Studies

Cassava anthracnose disease is a major economic disease of cassava in the tropics (2). Infection can lead to a significant loss in planting materials and total field crop failure. The disease has been reported to be transmitted mainly by a bug (Pseudotheraptus devastans Dist) (1). Open pollinated seeds from 13 cassava (Manihot esculenta Crantz) genotypes, stored for 10 months after harvest in 1994, were used to investigate the presence of the cassava anthracnose disease fungus. Seeds, 200 from each genotype, were surface sterilized, cultured on potato dextrose agar (PDA), and incubated for 8 days, at 25 ± 2°C. Microscopic examination indicated that Colletotrichum gloeosporioides was one of the seed-borne fungi, with up to 40% incidence recorded in some genotypes. Seeds from five susceptible genotypes selected for seed transmission studies were planted in fine, steam-sterilized soils in jiffy pots and watered daily for seedling emergence. At a height of 10 to 15 cm, the seedlings were transferred to plastic pots (10.5 cm in diameter) filled with sterilized mixture of soil and sand (2:2, vol/vol). Pots were placed close to each other to obtain a thick plant canopy. Temperature of 25 to 32°C and humidity of 80 to 98% were maintained. After 45 days, some plants had cassava anthracnose symptoms, including defoliation, wilt, and necrotic lesions. Stems, leaves, and roots of infected plants were washed, surface sterilized, and plated on PDA for 5 to 7 days. Microscopic observation of the fungus showed conidia of C. gloeosporioides. The rest of the plants were monitored for 3 months under vector-free conditions for typical anthracnose symptoms. Mean maximum wilt and defoliation of 35 to 38% was recorded in some genotypes. Conidial suspensions of C. gloeosporioides were used in stem-puncture inoculations of young, healthy cassava plants. The typical anthracnose symptoms of stem necrosis were observed 2 weeks after inoculation, confirming isolates as C. gloeosporioides f. sp. manihotis. This is the first report of C. gloeosporioides f. sp. manihotis being seed-borne and seed-transmitted in cassava. References: (1) B. Boher et al. Agronomie 3:989, 1983. (2) J. C. Lozano. PANS 20:30, 1974.

scholarly journals Documentation of fungal endophytes of black pepper (Piper nigrum L.) and their seed transmission studies

1970 ◽  
pp. 113-121
Author(s):  
K Sreeja ◽  
M Anandaraj ◽  
R Suseela Bhai
Keyword(s):  
Endophytic Fungi ◽  
Fungal Endophytes ◽  
Seed Transmission ◽  
Black Pepper ◽  
Piper Nigrum ◽  
In Planta ◽  
Fungal Propagules ◽  
Back Ground ◽  
Transmission Studies

The present study envisaged to document the endophytic fungal association with black pepper through a series of in vitro and in planta investigations. Black pepper was found to harbour endophytic fungal flora belonging to the genera Alternaria, Acremonium, Aspergillus, Cladosporium, Chaetomium, Curvularia, Colletotrichum, Fusarium, Humicola, Paecilomyces, Rhizoctonia, Phoma and non-sporulating forms. Further, it was found that the endocarp of black pepper seed is free from culturable endophytic fungi. This was evident from the absence of culturable fungi in in vitro grown black pepper seedlings. The growth of fungi from the seedlings grown under green house conditions reveal that the fungal endophytes establish from fungal propagules falling on the (test) plants that may enter the plant tissues as back ground inoculum and grow as endophyte. This was also supported by the study that the type of endophytic fungi that harbour black pepper plants varied with geographical locations from where the samples were collected.

PLANT-SEED TRANSMISSION OF SOYBEAN IN Colletotrichum truncatum

Nucleus ◽  
2015 ◽  
Vol 12 (1) ◽  
Author(s):  
Gabrielle de Lima MASSON ◽  
Bruno Agostini COLMAN ◽  
Paulo Rogério Beltramin da FONSECA ◽  
Alexandre Dinnys ROESE
Keyword(s):  
Seed Transmission ◽  
Colletotrichum Truncatum ◽  
Plant Seed

scholarly journals Large-Scale Seedling Grow-Out Experiments Do Not Support Seed Transmission of Sweet Potato Leaf Curl Virus in Sweet Potato

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 139
Author(s):  
Sharon A. Andreason ◽  
Omotola G. Olaniyi ◽  
Andrea C. Gilliard ◽  
Phillip A. Wadl ◽  
Livy H. Williams ◽  
...  
Keyword(s):  
Sweet Potato ◽  
Large Scale ◽  
Seed Transmission ◽  
Potato Production ◽  
Potato Leaf ◽  
Vector Transmission ◽  
Leaf Curl Virus ◽  
Seed Coats ◽  
Potato Seedlings ◽  
Leaf Curl

Sweet potato leaf curl virus (SPLCV) threatens global sweet potato production. SPLCV is transmitted by Bemisia tabaci or via infected vegetative planting materials; however, SPLCV was suggested to be seed transmissible, which is a characteristic that is disputed for geminiviruses. The objective of this study was to revisit the validity of seed transmission of SPLCV in sweet potato. Using large-scale grow-out of sweet potato seedlings from SPLCV-contaminated seeds over 4 consecutive years, approximately 23,034 sweet potato seedlings of 118 genotype entries were evaluated. All seedlings germinating in a greenhouse under insect-proof conditions or in a growth chamber were free of SPLCV; however, a few seedlings grown in an open bench greenhouse lacking insect exclusion tested positive for SPLCV. Inspection of these seedlings revealed that B. tabaci had infiltrated the greenhouse. Therefore, transmission experiments were conducted using B. tabaci MEAM1, demonstrating successful vector transmission of SPLCV to sweet potato. Additionally, tests on contaminated seed coats and germinating cotyledons demonstrated that SPLCV contaminated a high percentage of seed coats collected from infected maternal plants, but SPLCV was never detected in emerging cotyledons. Based on the results of grow-out experiments, seed coat and cotyledon tests, and vector transmission experiments, we conclude that SPLCV is not seed transmitted in sweet potato.

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