Clonal variability in the response of Sitobion avenae (Homoptera: Aphididae) to resistant and susceptible wheat

Abstract

The development and reproduction of 60 clones of Sitobion avenae (Fabricius), collected in the Rennes Basin, were compared on a resistant Triticum monococcum (Linnaeus) line (Tm44) and a susceptible Triticum aestivum (Linnaeus) cultivar (Arminda). All clones had lower larval survival and mean fecundity when reared on Tm44 in comparison with Arminda. They all performed equally well on Arminda whereas there was a marked and continuously distributed variation in performance parameters among clones maintained on Tm44. The plant species, from which clones originated, significantly affected aphid performances on resistant Tm44. A more detailed experiment was carried out with four clones, shown to differ in their level of fitness on Tm44. Their performances were compared on resistant (Tm44 and Tm46) and susceptible (Tm47 and Arminda) wheat genotypes. On the basis of larval development time and intrinsic rate of natural increase (rm), two types of response were distinguished among the four clones: clones Sa1 and Sa39 appeared to be less affected by Tm44 and Tm46 resistance than Sar2 and Sa48. Moreover, Tm46 was much less resistant to clone Sal than was Tm44. These results are discussed in relation to the origins of the variation in performance of S. avenae on resistant wheat, and their implications in plant breeding for resistance to S. avenae.

Coexistence in space and time of sexual and asexual populations of the cereal aphid Sitobion avenae

“…To reduce the probability of resampling multiple individuals of the same clone, a minimum of half a metre separated each individual collected. Each parthenogenetic female collected was allowed to reproduce on a wheat seedling, according to standard methods (Caillaud et al 1995) to establish a parthenogenetic line. After elimination of parasitised and diseased aphids, 674 lineages were initiated: 352 from wheat, 182 from barley, 108 from maize, 22 from oats and 10 from cocksfoot.…”

“…After elimination of parasitised and diseased aphids, 674 lineages were initiated: 352 from wheat, 182 from barley, 108 from maize, 22 from oats and 10 from cocksfoot. These clones were reared for 3 months after field collection in standard conditions ensuring continuous parthenogenetic reproduction (20°C, 16 h light: 8 h dark (L16:D8); Simon et al 1991;Caillaud et al 1995).…”

“…It possesses a wide range of breeding systems (holocyclics, intermediates, androcyclics, anholocyclics), and gene flow occurs between holocyclics, intermediates and androcyclics, at least in laboratory experiments (Dedryver et al 1998b;Simon et al 1999). S. avenae also displays variation in host plant preferences (Caillaud et al 1995;De Barro et al 1995a, 1995bSunnucks et al 1997;Haack et al 2000) and colour polymorphism, with clones varying from pale green to dark brown (Lowe 1981;Weber 1985;Dedryver et al 1994). A recent study using microsatellite markers showed strong genetic differentiation between northern and southern populations of S. avenae in France, likely resulting from geographic partitioning of breeding system variation (Simon et al 1999).…”

Intra-specific variation and inheritance of BYDV-PAV transmission in the aphid Sitobion avenae

“…Consequently, natural populations of a given aphid species encompass a 'mixture' of different sympatric clonal lines (generally termed 'clones' in the literature), which are most often genetically and phenotypically distinct, and which reproduce by apomictic parthenogenesis for several months (if the sexual phase occurs) up to several years (if not) before disappearing. Thus, aphids are particularly convenient organisms for studying (i) the stability in time of phenotypic characters, since sexual reproduction and consequently annual recombination can be prevented, by rearing aphids under a permanent for biological traits such as (i) the ability to produce sexual morphs (Blackman, 1971;Simon et al, 1991;Dedryver et al, 1998) or winged morphs (Dedryver et al, 1990), (ii) host-plant preference (Caillaud et al, 1995;Bournoville et al, 2000) and (iii) transmission of plant viruses (Rochow and Eastop 1966;Bourdin et al, 1998).…”

Aphid-AutoEPG software for analysing electrically monitored feeding behaviour of aphids

“…70-100 EPG parameters of visually analysed EPG signals (see www.EPGsystems.eu, page downloads), which provides more detailed information on the effects of (1) plants on plant virus transmission (Fereres and Collar 2001;Tjallingii and Prado 2001), (2) plant protection substances on pests (Nisbet et al 1993) and (3) the location of aphid resistance in (host) plants (van Helden and Tjallingii l993;Caillaud et al 1995;Alvarez et al 2006). The success of this electrical monitoring technique arises from the fact that EPG waveforms and the details of the patterns within these waveforms recorded for different species of aphids are very similar.…”