Geographical Distribution of Four Sugarcane yellow leaf virus Genotypes

Abstract

Specific primer pairs were designed to distinguish four genotypes (BRA for Brazil, CUB for Cuba, PER for Peru, and REU for Réunion Island) of Sugarcane yellow leaf virus (SCYLV) by reverse transcription-polymerase chain reaction (RT-PCR). A unique genome fragment was amplified from each genotype, with the exception of genotypes BRA and PER that are phylogenetically relatively close and were designated genotype BRA-PER. These RT-PCR primers were then used to identify the SCYLV genotype(s) present in 18 different sugarcane growing locations in the world, and 245 leaf samples infected by the virus were analyzed. Most samples were infected by only one of the three genotypes, but mixed infections occurred. Genotype BRA-PER was found in all sugarcane growing locations, whereas genotypes CUB and REU were each found in four geographical locations only. Genotypes BRA-PER, CUB, and REU were all three detected in locally bred sugarcane cultivars in Guadeloupe, indicating local transmission of these genotypes. In contrast, only genotypes BRA-PER and CUB were found in locally bred cultivars in Brazil, whereas genotype REU was detected in this country in cultivar R570 imported from Réunion. Similarly, genotypes BRA-PER and REU are both present in Réunion, but genotype BRA-PER has not, as of yet, spread on this island. Presence of several SCYLV genotypes in Brazil, Colombia, Guadeloupe, Mauritius, and Réunion suggests different virus introductions and/or different evolution histories of the virus after its introduction into a new environment.

Sugarcane yellow leaf virus introduction and spread in Hawaiian sugarcane industry: Retrospective epidemiological study of an unnoticed, mostly asymptomatic plant disease

“…The time range (1960)(1961)(1962)(1963)(1964)(1965)(1966)(1967)(1968)(1969)(1970) where SCYLV is suspected to have arrived and spread in Hawaii is corroborated by a few other facts: the infected windbreak plants in the papaya plantations, the BRA-PER strain infection of the Hawaiian cultivars, which were exported to Peru in 1982, and finally the BRA-PER-strain of the variety R570 in Hawaii. That cultivar was imported from Réunion in 1981 and contains the BRA-PER strain (Abu Ahmad et al 2006), although the same cultivar in Réunion harbors the REU strain and, in Mauritius, both REU and BRA-PER. Thus, Réunion was apparently SCYLVfree at 1981 when this cultivar was imported to Hawaii.…”

“…The presence of SCYLV in the infected cultivars over so many replantings did not therefore originate from de novo infection in the greenhouse. (Schenck et al 1997;Vega et al 1997;Comstock et al 1998;Victoria et al 1998;Moutia and Saumtally 1999;Arocha et al 1999;Alegria et al 2000;Smith et al 2000;Avila et al 2001;Comstock et al 2002;Nadif et al 2002;Rassaby et al 2004;Abu Ahmad et al 2006). The numbers in the squares show the year, when the tests for SCYLV were made respectively were reported.…”

“…Thus no definitive hint as to the origin of an imported SCYLVinfected cultivar could be obtained from the import records. The company names listed here were those which existed at the time when the plantation was closed SCYLV-types in sugarcane cultivars from Hawaii and clone R570 from Réunion Four types of SCYLV had been identified so far (Moonan and Mirkov 2002;Abu Ahmad et al 2006) and one plant had been analysed from the Hawaii collection, namely R570, which is a cultivar from Réunion. This plant contained the BRA-PER strain of SCYLV, not the REU-strain, which is typical for Réunion and which was found in R570 on Reúnion, Guadeloupe and Mauritius (Table 3).…”

“…Later, similar symptoms were reported from mainland United States (Comstock et al 1994), Brazil (Vega et al 1997), Mauritius (Moutia and Saumtally 1999) and many other sugarcane countries (Bailey et al 1996;Victoria et al 1998;Lockhart and Cronje 2000). The polerovirus Sugarcane yellow leaf virus (SCYLV) was identified as a possible causal agent (Vega et al (Smith et al 2000;Moonan et al 2000) and 3-4 clusters of strains could be grouped, whereby a Colombian strain was proposed as the original population, which diverged out of the polerovirus group (Moonan and Mirkov 2002;Abu Ahmad et al 2006). The fact that the disease was detected not earlier than in the 1990s points to a more recent worldwide distribution, even though a report in 1968 about yellow wilt in sugarcane in Eastern Africa is attributed as, possibly, a first account of yellow leaf (Ricaud 1968;Bailey et al 1996).…”

RT-PCR and quantitative real-time RT-PCR detection of Sugarcane Yellow Leaf Virus (SCYLV) in symptomatic and asymptomatic plants of Hawaiian sugarcane cultivars and the correlation of SCYLV titre to yield

“…(family Luteoviridae) with a single stranded positive sense RNA genome, that has been reported to infect sugarcane worldwide (Vega et al 1997;Comstock et al 1998; Moutia and Saumtally 1999;Abu Ahmad et al 2006). Like others in this group, SCYLV is phloem-limited (Vega et al 1997;Schenck et al 1997;Lehrer et al 2007).…”