Premium
Differential colonization of wheat cultivars by two biotypes of Russian wheat aphid (Homoptera: Aphididae)
Author(s) -
QURESHI JAWWAD A.,
JYOTI JAWAHAR L.,
MICHAUD J. P.
Publication year - 2005
Publication title -
insect science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 45
eISSN - 1744-7917
pISSN - 1672-9609
DOI - 10.1111/j.1005-295x.2005.00042.x
Subject(s) - biology , cultivar , aphididae , russian wheat aphid , homoptera , aphid , infestation , nymph , horticulture , instar , botany , agronomy , pest analysis , larva
Susceptible and resistance wheat cultivars, Triticum aestivum L, were presented to two biotypes of Russian wheat aphid, Diuraphis noxia (Mordvilko), in multiple choice tests to assay their relative acceptability as host plants. Both apterae (third and fourth instars) and alate adults were offered plants at the two‐leaf stage in different cultivar combinations at 22 ± 1 °C and 16: 8 (L: D) hour photoperiod. Apterae were released from Petri dishes in the center of a circle of test plants, whereas alatae dispersed from a mature aphid colony to settle on plants arranged in rows. Both alatae and apterous nymphs of both biotypes readily colonized all cultivars tested: ‘2137’, ‘Akron’, ‘Ankor’, ‘Halt’, ‘Jagger’, ‘Prairie Red’, ‘Stanton’, ‘TAM107’, ‘TAM110’, ‘Trego’, ‘Yuma’, and ‘Yumar’. Fewer biotype 1 apterae responded (settled and fed) in the combination containing more resistant ( Dn 4‐ and Dny‐expressing) cultivars, compared to the combinations that had fewer. The reverse was true for biotype 2 apterae; more aphids responded in the combination containing the largest number of Dn 4 expressing cultivars. Differential colonization of cultivars was observed in only one combination, in which biotype 2 apterae colonized Akron and Yumar in larger numbers than they did Stanton and Yuma. A separate experiment confirmed that, 48 hours after infestation, more biotype 2 apterae abandoned plants of Yuma than plants of Yumar. This differential response was likely due to genetic differences between the two ‘near isogenic’ lines that include the lack of Dn 4 expression in Yuma. Choice tests with alatae did not result in differential rates of cultivar colonization by either biotype in any combination tested. These results suggest that young wheat plants appear to lack any meaningful antixenosis toward D. noxia , even though the aphids appear to perceive, and sometimes respond to, certain differences in cultivar suitability.