Alfalfa mosaic and pea seed-borne mosaic viruses in cool season crop, annual pasture, and forage legumes: susceptibility, sensitivity, and seed transmission

2001 ◽  
Vol 52 (7) ◽  
pp. 771 ◽  
Author(s):  
L. J. Latham ◽  
R. A. C. Jones

Field experiments determined the susceptibilities and sensitivities of a wide range of crop, annual pasture, and forage legumes to infection with alfalfa mosaic (AMV) and pea seed-borne mosaic (PSbMV) viruses. Seed harvested from most of the species was tested for virus seed transmission. With AMV, all 23 Cicer arietinum genotypes tested were ranked as highly susceptible, and 9 out of 19 Lens culinaris genotypes as highly susceptible, 8 susceptible, 1 moderately resistant, and 1 resistant. Genotypes of Vicia narbonensis (5), Lathyrus cicera (5), L. sativus (5), L. ochrus(2), V. sativa (1), and V. benghalensis (1) were highly susceptible, susceptible, or moderately resistant. Genotypes of Pisum sativum (5) and V. faba(3) were susceptible, moderately resistant, or resistant but 1 genotype of V. faba was not found infected. Sensitivities ranged from low in L. ochrus to high in some genotypes of most species tested exceptV. benghalensis. The 20 genotypes (19 species) of pasture and forage legumes ranged from ‘not found infected’ in Hedysarum coronarium to ‘highly susceptible’ in Ornithopus sativus and Trifolium resupinatum. Sensitivity varied from low in T. michelianum to very high in Biserrula pelecinusand Ornithopus sativus. With PSbMV, the genotypes ofP. s a t i v u m (17), V. narbonensis (5), and L. cicera(3) were ranked as highly susceptible, susceptible, or moderately resistant, while those of L. ochrus(3), V. faba(6), V. sativa (3), V. benghalensis (2) and V. ervilia(1) were either moderately resistant or resistant. The genotypes of C. arietinum (6) and Lens culinaris (6) were all resistant. With L. sativus, 2 genotypes were resistant and 1 was not found infected. Sensitivities ranged from low in some P. sativum genotypes to high in some ofL. ciceraand V. narbonensis. The seed coats of 9 crop legume species developed necrotic ring markings, a serious quality defect due to PSbMV infection. Of the 19 genotypes (1/species) of pasture and forage legumes, 4 were resistant with only symptomless infection developing and the remainder not found infected. In glasshouse inoculations to genotypes not found infected in the field, AMV infected V. faba cv. Ascot systemically butH. coronarium cv. Grimaldi (with AMV) and L. sativus BIO L254 (with PSbMV) only became infected in inoculated leaves, H. coronarium developing a localised hypersensitive reaction. Seed transmission of AMV was detected in L. cicera(2%), L. sativus (0.9–4%), V. benghalensis(0.9%), V. narbonensis (0.1%), and V. sativa (0.7%). It was also found in 15 pasture and forage legume species, ranging from 0.05% in T. michelianum to 7% in Trigonella balansae. Seed transmission of PSbMV was detected in L. cicera(0.4%), L. clymenum (5%), L. ochrus (0.7%), L. sativus (1%), P sativum(1–18%), V. benghalensis (0.1%), V. faba (2%), and V. sativa (0.3%). The implications of these findings and their importance to the management of these and other virus diseases are discussed.

2000 ◽  
Vol 51 (3) ◽  
pp. 325 ◽  
Author(s):  
S. J. McKirdy ◽  
R. A. C. Jones ◽  
L. J. Latham ◽  
B. A. Coutts

Seven field and 5 glasshouse experiments were done during 1994–98 to determine the relative susceptibilities and sensitivities of a wide range of alternative annual pasture, forage, and crop legumes to infection with isolate MI of bean yellow mosaic virus (BYMV). Seed harvested from some species was also tested for seed transmission of the virus. Seven of 18 genotypes belonging to 17 species of annual pasture and forage legumes evaluated in 2 replicated field experiments were ranked as highly susceptible to BYMV, 7 as susceptible, 2 as moderately resistant, 1 as resistant, and 1 as highly resistant. The most susceptible and sensitive were Biserrula pelecinus, Trifolium cherleri, T. incarnatum, and T. spumosum. Ornithopus sativus was resistant but sensitive, whereas Hedysarum coronarium was highly resistant. H. coronarium was not infected when manually inoculated repeatedly with 3 different BYMV isolates. Seventy-three of the 94 genotypes of 7 crop legume species tested in the same replicated field experiments were ranked as highly susceptible, including 58/68 of Lens culinaris. Of the remaining genotypes, 6 were susceptible, 5 moderately resistant, 9 resistant, and 1 highly resistant. Five other crop legumes were included in other field experiments in which these species were ranked as highly susceptible (1) or resistant (4). Overall, the most susceptible and sensitive crop legume species were Lens culinaris (most genotypes), Lathyrus cicera, L. ochrus, and Vicia narbonensis. Lathyrus sativus (3 genotypes only), V. sativa (4 genotypes), Cicer arietinum, Pisum sativum, and V. faba were resistant to isolate MI, and Lens culinaris ILL7163 was highly resistant. When infected, C. arietinum was ranked as highly sensitive but symptoms within the other resistant crop species varied in sensitivity between genotypes. Extreme resistance was confirmed in Lens culinaris ILL7163 when it was manually and aphid-inoculated repeatedly with 3 different BYMV isolates. When testing seedlings for seed transmission of BYMV, germination on moist paper towels before testing usually proved more effective than growing in soil in the glasshouse. Low rates of seed transmission of BYMV (0.03–1%) were detected in 9 alternative pasture or forage and 3 alternative crop legume species. This is the first report of seed transmission of BYMV in these species. The pasture or forage species with the highest seed transmission rates were T. clypeatum and T. spumosum (both 1%). The crop legume species in which seed transmission was found were L. cicera (0.1%), L. sativus (0.2%), and V. sativa (0.5%). The high susceptibility and sensitivity to BYMV in some alternative annual pasture, forage, and crop legumes is a cause for concern, especially when they are intended for sowing in BYMV-prone high rainfall zones. Seed transmission of BYMV also leads to inadvertent introduction of the virus to new sites.


2001 ◽  
Vol 52 (6) ◽  
pp. 683 ◽  
Author(s):  
L. J. Latham ◽  
R. A. C. Jones ◽  
S. J. McKirdy

Seven field experiments were done in 19944—98 to determine the relative susceptibilities and sensitivities of a wide range of alternative crop, annual pasture, and forage legumes to infection with cucumber mosaic virus (CMV). Seed harvested from some species was tested for seed transmission of the virus. Most of the 24 genotypes of Cicer arietinum and 39 of Lens culinaris tested in 2 replicated field experiments were ranked as highly susceptible or susceptible; moderate resistance was recorded in 8Lens culinaris genotypes, the most resistant of which was ILL7163, and in C. arietinum cv. Amethyst Mutant. Sensitivity varied from low to high in different Lens culinaris genotypes, whereas in C. arietinum they were all sensitive or highly sensitive. In 4 other experiments, 12 species (49 genotypes) of other crop legumes were ranked as follows: Vicia narbonensis susceptible to moderately resistant, V. ervilia susceptible, Pisum sativum resistant, and V. faba resistant to potentially highly resistant; Lathyrus cicera,L. clymenum, L. ochrus, L. sativus, L. tingitanus, V. benghalensis, V. monantha, and V. s a t i v a were not infected. V. ervilia andV. faba were very sensitive to infection, but V. narbonensis had intermediate sensitivity and P. s a t i v u m was tolerant. When single genotypes of each of 16 pasture and forage species were tested in 2 replicated field experiments, 1 was highly susceptible, 3 were susceptible, 9 moderately resistant, 2 resistant, and 1 was potentially highly resistant. The 4 most susceptible were the sensitive species Trifolium incarnatum and T. isthmocarpum and the intermediately sensitive species T. michelianum and T. vesiculosum. T. squarrosum (intermediate sensitivity) and T. spumosum (very sensitive) were resistant and Ornithopus sativus was not infected. In sap inoculations, L. ochrus,L. sativus, and P. sativum occasionally became infected. In aphid inoculations,Lens culinaris ILL7163 and V. faba became infected only rarely and V. benghalensis cv. Popany developed a systemic hypersensitive reaction. The following were not infected in the field or glasshouse: L. cicera ATC80521, L. clymenum C7022, O. sativus cv. Cadiz, and V. sativa cv. Languedoc.Seed transmission of CMV was detected for the first time in one crop species, V. narbonensis(0.1mp;mdash;0.8%), and confirmed in C. arietinum (0.2–0.3%) and Lens culinaris (0.3%). It was also detected in T. cherleri (0.05%), T. clypeatum (0.05%), T. dasyurum (0.1%), T. incarnatum (5%), T. purpureum (0.04%), T. spumosum (0.5%), T. squarrosum (0.1%), and T. vesiculosum (1%), but not in 8 other pasture or forage species. The high susceptibility and sensitivity to CMV of some alternative crop, annual pasture, and forage legumes is cause for concern, especially when they are intended for sowing in CMV-prone high rainfall zones. Infection of seed stocks with CMV is also of concern as it leads to inadvertent introductions of the virus.


Nematology ◽  
2019 ◽  
Vol 21 (6) ◽  
pp. 557-571 ◽  
Author(s):  
Abdelfattah A. Dababat ◽  
Fouad Mokrini ◽  
Salah-Eddine Laasli ◽  
Şenol Yildiz ◽  
Gül Erginbas-Orakci ◽  
...  

Summary The root-lesion nematode, Pratylenchus thornei, attacks a wide range of crops and causes significant reductions in global grain production. Breeding programmes are currently restricted to using parents with moderate resistance to P. thornei as cereal cultivars with complete resistance are yet to be identified. This study evaluated 484 of CIMMYT’s spring wheat accessions for resistance to P. thornei of which 56 lines were pre-identified as resistant under controlled growth room conditions. These lines were further evaluated for their resistance and tolerance reactions under field conditions, where 14 accessions maintained their resistance and 16 were moderately resistant against P. thornei. Four lines gave excellent resistant and tolerance reactions to P. thornei. The relationship between the nematode reproduction factor (Pf/Pi) and wheat grain yield in field experiments fits a linear regression model. These findings could be useful for improving P. thornei resistance in wheat.


1979 ◽  
Vol 19 (99) ◽  
pp. 495 ◽  
Author(s):  
RCN Laurence

Field experiments are described comparing a wide range of annual, winter-growing legume species with regard to their grain yield and protein content in South Australia. In 1974, a year when rainfall was considerably above average, Vicia faba (fieldbeans) outyielded all other species at each of two sites, eighty lines producing a mean yield of 8.2 t ha-1 of air-dry grain. In 1975, when rainfall was again generally above average but poorly distributed, V. faba, V. sativa and certain Lathyrus species yielded well, while other crops maintained average yields or failed in specific environments. The relative merits of new crop species in the diversification of rotations in dry land farming are discussed and it is concluded that field beans could be developed rapidly into a valuable alternative grain crop.


2008 ◽  
Vol 59 (12) ◽  
pp. 1130 ◽  
Author(s):  
B. A. Coutts ◽  
R. T. Prince ◽  
R. A. C. Jones

Field and glasshouse experiments (3 of each) were done during 2003–06 to determine the responses of a range of genotypes belonging to 13 species of cool-season crop legumes to infection with Pea seed-borne mosaic virus (PSbMV). Seed quality defects were determined and genotypes of some species were also tested for seed transmission of the virus. In field experiments, of 39 genotypes of field pea (Pisum sativum) evaluated, 15 were ranked as highly susceptible, 10 susceptible, 9 moderately resistant, and 5 resistant, while all 7 lupin species (Lupinus spp.) tested were resistant. In glasshouse sap and graft inoculations with PSbMV to genotypes not found infected in the field and 2 additional lupin species, no virus was detected in any of the 9 lupin species or in 5 field pea genotypes tested. Thus, the lupins all appeared to be non-hosts and the 5 field pea genotypes had resistance to the 2 PSbMV isolates used to inoculate them. All 14 genotypes of faba bean (Vicia faba) evaluated in the field were ranked highly susceptible, while 12 out of 16 lentil (Lens culinaris) genotypes were ranked as highly susceptible and 4 as susceptible. Chickpea (Cicer arietinum) genotypes were moderately resistant (50) or susceptible (7). Once infected, plant sensitivities (symptom severities) ranged from low in some field pea and most lentil genotypes to high in most faba bean genotypes. Chickpea genotypes all were ranked as moderately sensitive. Seed lots harvested from PSbMV-infected plants of field pea, faba bean, and chickpea all showed severe seed quality defects, but lentil was usually less affected. The predominant seed symptoms were necrotic rings and line markings on the seed coat, malformation, reduced size, and splitting. Kabuli chickpea types also showed darkening of the seed coat. Seed transmission of PSbMV was detected in faba bean (0.2%) and field pea (5–30%). When PSbMV infection foci were introduced into plots of lentil cv. Nugget, the virus spread to the lentil plants and decreased shoot dry weight by 23%, seed yield by 96%, and individual seed weight by 58%. Seed transmission of PSbMV (6%) was detected in seed from the infected lentil plants. In a survey for possible viral seed symptoms, all seed lots of kabuli chickpea (5) and field pea (70), and 10 of 18 of faba bean were affected, but none of the 23 of lentil. When seedlings from 16 faba bean and 7 field pea seed lots were tested for 3 viruses, neither Broad bean stain virus nor Broad bean true mosaic virus was detected, but PSbMV was found in 5 field pea seed lots at incidences of <1–14%. PSbMV was detected in commercial field pea seed stocks of cvv. Kaspa (33) and Parafield (12) at incidences of 0.5–47% and 0.3–30%, respectively. The implications of these findings in terms of genotype susceptiblility and sensitivity to PSbMV infection and their importance for the management of PSbMV in legume crops are discussed.


2016 ◽  
Vol 3 (4) ◽  
Author(s):  
H. K. Singh ◽  
Mahesh Singh ◽  
M. P. Chauhan ◽  
Tripti Srivastava ◽  
Manoj Kumar Singh

Field experiments were conducted during 2010-11 to 2011-12 crop seasons to identify resistant genotypes for the management of bacterial blight/black rot caused by Xanthomonas campestris pv. campestris (Pammel) Dawson. Symptoms of disease were recorded 40-45 days after sowing in different localities of Faizabad district of U.P. Disease was characterized by the initial symptoms appeared as dark color streaks on the stem from ground level, which girdle the stem making very soft and hollow followed by rotting. Lower leaves showed midrib cracking ‘V’ shaped yellowing on the leaf margin, browning of veins and weathering. Profuse exudation of yellowish fluid from the affected stem and leaves may also occur. Out of 110 genotypes screened, ten entries namely T-27, GSL-1, PHR-2, DRMR-243, PBC-9221, JMTA-9, EC-399299, EC-38899, HNS-9605 and HNS-004 were recorded resistant and forty four were moderately resistant. Rest of the genotypes proved moderately susceptible from X. campestris pv. campestris.


Weed Science ◽  
1979 ◽  
Vol 27 (5) ◽  
pp. 497-501 ◽  
Author(s):  
C. D. Boyette ◽  
G. E. Templeton ◽  
R. J. Smith

An indigenous, host-specific, pathogenic fungus that parasitizes winged waterprimrose [Jussiaea decurrens(Walt.) DC.] is endemic in the rice growing region of Arkansas. The fungus was isolated and identified asColletotrichum gloeosporioides(Penz.) Sacc. f.sp. jussiaeae(CGJ). It is highly specific for parasitism of winged waterprimrose and not parasitic on creeping waterprimrose (J. repensL. var.glabrescensKtze.), rice (Oryza sativaL.), soybeans [Glycine max(L.) Merr.], cotton (Gossypium hirsutumL.), or 4 other crops and 13 other weeds. The fungus was physiologically distinct from C.gloeosporioides(Penz.) Sacc. f. sp.aeschynomene(CGA), an endemic anthracnose pathogen of northern jointvetch[Aeschynomene virginica(L.) B.S.P.], as indicated by cross inoculations of both weeds. Culture in the laboratory and inoculation of winged waterprimrose in greenhouse, growth chamber and field experiments indicated that the pathogen was stable, specific, and virulent in a wide range of environments. The pathogen yielded large quantities of spores in liquid culture. It is suitable for control of winged waterprimrose. Winged waterprimrose and northern jointvetch were controlled in greenhouse and field tests by application of spore mixtures of CGJ and CGA at concentrations of 1 to 2 million spores/ml of each fungus in 94 L/ha of water; the fungi did not damage rice or nontarget crops.


Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.


Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 99
Author(s):  
Viktorija Gecaitė ◽  
Aušra Arlauskienė ◽  
Jurgita Cesevičienė

Cereal-legume intercropping is important in many low-input agricultural systems. Interactions between combinations of different plant species vary widely. Field experiments were conducted to determine yield formation regularities and plant competition effects of oat (Avena sativa L.)–black medick (Medicago lupulina L.), oat–white clover (Trifolium repens L.), and oat–Egyptian clover (T. alexandrinum L.) under organic farming conditions. Oats and forage legumes were grown in mono- and intercrops. Aboveground dry matter (DM) measured at flowering, development of fruit and ripened grain, productivity indicators, oat grain yield and nutrient content were established. The results showed that oats dominated in the intercropping systems. Oat competitive performance (CPo), which is characterized by forage legumes aboveground mass reduction compared to monocrops, were 91.4–98.9. As the oats ripened, its competitiveness tendency to declined. In oat–forage legume intercropping systems, the mass of weeds was significantly lower compared to the legume monocrops. Oats and forage legumes competed for P, but N and K accumulation in biomass was not significantly affected. We concluded that, in relay intercrop, under favourable conditions, the forage legumes easily adapted to the growth rhythm and intensity of oats and does not adverse effect on their grain yield.


2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Armin Sorooshian ◽  
Hanh T. Duong

Two case studies are discussed that evaluate the effect of ocean emissions on aerosol-cloud interactions. A review of the first case study from the eastern Pacific Ocean shows that simultaneous aircraft and space-borne observations are valuable in detecting links between ocean biota emissions and marine aerosols, but that the effect of the former on cloud microphysics is less clear owing to interference from background anthropogenic pollution and the difficulty with field experiments in obtaining a wide range of aerosol conditions to robustly quantify ocean effects on aerosol-cloud interactions. To address these limitations, a second case was investigated using remote sensing data over the less polluted Southern Ocean region. The results indicate that cloud drop size is reduced more for a fixed increase in aerosol particles during periods of higher ocean chlorophyll A. Potential biases in the results owing to statistical issues in the data analysis are discussed.


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