Characteristics of Beet Yellows Closterovirus Transmission to Sugar Beets by Aphis fabae

Abstract

Laboratory studies were conducted on the characteristics of beet yellows closterovirus (BYV) transmission to sugar beets by the bean aphid, Aphis fabae. The relative transmission efficiency and the retention, acquisition, and inoculation thresholds were evaluated using clonal aphid colonies. Transmission efficiency was studied between different apterous aphid species (A. fabae and Myzus persicae ), between alate and apterous morphs of A. fabae and M. persicae, and among five clonal aphid colonies of A. fabae. Results indicated, on average, that apterous M. persicae transmitted twice as efficiently as apterous A. fabae (60 and 34%, respectively), apterous forms of A. fabae were equally efficient in transmitting BYV as compared with alate A. fabae (28 and 29%, respectively), and the five clonal colonies of A. fabae ranged from 28 to 40% transmission efficiency with an average of 34%. The maximum retention time recorded for BYV by A. fabae was between 24 and 48 h. After a 1-h acquisition access, a transmission efficiency of 10% was obtained, with maximum transmission efficiency (the highest average percent transmission that is statistically different from all other previous averages) of 39% reached after 6 h of acquisition access. Inoculation thresholds occurred within 1 h, with maximum transmission efficiency (42%) reached after a 6-h inoculation access. Using an electronic monitoring system, a range of 9 to 38 min (20.5 mean) was recorded for the stylets of A. fabae to reach the phloem sieve elements. This was consistent with our threshold of a 20-min acquisition access recorded through direct observation.

Quantitative detection of Citrus tristeza virus in plant tissues and single aphids by real-time RT-PCR

“…CTV can be acquired after a short accession period on an infected plant, but high rates of acquisition are only achieved when aphids feed for a long time, as it is more likely that the aphid reaches the phloem. According to this hypothesis, Limburg et al (1997) suggested that Beet yellows virus (BYV), another Closterovirus, is acquired from sieve elements by aphids during phloem ingestion phase, correlating with the average time needed to reach the sieve elements with the minimum time needed for virus acquisition (20 min). However, the possibility cannot be excluded that the virus may also be acquired from non-phloem tissues.…”

“…Subsequent spread by aphid vectors, in a semi-persistent manner, caused and is still causing major epidemics (Cambra et al 2000a). Closterovirus transmission has no latent period and acquisition and inoculation periods vary from at least 30 min to seconds (BarJoseph et al 1989;Limburg et al 1997). The most efficient vector of CTV is Toxoptera citricida (Yokomi et al 1989).…”

Molecular Analysis of ORF6, ORF7 and ORF8 of Beet yellows virus Iranian Isolate

“…; Limburg et al. ). In this study, we determined molecular characterization of three ORFs including ORF6, ORF7 and ORF8 of an Iranian isolate of BYV.…”

Behavioural avoidance and enhanced dispersal in neonicotinoid-resistant Myzus persicae (Sulzer)

“…Aphids acquire plant viruses during feeding (for a review see Fereres and Moreno). Virions enter and adhere to the aphid stylets or midgut during either short probes of the mouthparts into the plant tissue in the case of non‐persistent viruses, or longer sustained phloem feeding in the case of persistent viruses . Transmission occurs when a viruliferous aphid disperses from a viral host plant and relocates to another, healthy, host plant.…”

“…Virions enter and adhere to the aphid stylets or midgut 46 during either short probes of the mouthparts into the plant tissue in the case of non-persistent viruses, 47 or longer sustained phloem feeding in the case of persistent viruses. 48,49 Transmission occurs when a viruliferous aphid disperses from a viral host plant and relocates to another, healthy, host plant. The inoculation of nonpersistent viruses is associated with salivation during brief cell punctures by the stylets 50,51 while that of persistent viruses is thought to occur during phloem salivation.…”