Acetamiprid resistance and fitness costs of melon aphid, Aphis gossypii: An age-stage, two-sex life table study

The spread of watermelon mosaic virus by the melon aphid (Aphis gossypii Glover) was 31%, 74%, and 71% less to a melon aphid-resistant muskmelon (Cucumis melo L.) breeding line than to the susceptible recurrent parent in a field cage study. Aphid-resistant and susceptible plants served equally well as the virus source. The highest rate of infection (97.9%) was noted when target plants were all melon-aphid susceptible, least (26.7%) when the target plants were all melon-aphid resistant, and intermediate (69.4%) when the target plants were an equal mix of aphid-resistant and susceptible plants. The number of viruliferous aphids per plant required to cause a 50% infection varied from five to 20 on susceptible controls and from 60 to possibly more than 400 on a range of melon aphid-resistant populations. An F family from a cross of the melon aphid-resistant AR Topmark (AR TM) with the susceptible `PMR 45' had significantly less resistance to virus transmission than AR TM. Breeding line AR 5 (an aphid-resistant population with `PMR 5' as the recurrent parent) had significantly greater resistance to transmission than other aphid-resistant populations.

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Melon PI 414723 Is Resistant to Papaya Ringspot Virus Watermelon Strain

HortScience ◽

10.21273/hortsci.31.4.602b ◽

1996 ◽

Vol 31 (4) ◽

pp. 602b-602

Author(s):

James D. McCreight

Keyword(s):

Cucumis Melo ◽

Powdery Mildew Resistance ◽

Aphis Gossypii ◽

Dominant Gene ◽

Uttar Pradesh ◽

Virus Multiplication ◽

Ringspot Virus ◽

Papaya Ringspot Virus ◽

Systemic Necrosis ◽

Melon Aphid

PI 414723 has received much attention from melon (Cucumis melo L.) breeders, pathologists, and entomologists for resistances to zucchini yellow mosaic and watermelon mosaic viruses, including resistances to virus multiplication and subsequent transmission by the melon aphid, powdery mildew resistance, and melon aphid (Aphis gossypii Glover). PI 414723 was derived from PI 371795, which was a contaminant in cucumber (Cucumis sativus L.) PI 175111 collected in 1948 by Walter N. Koelz in Mussoorie, Uttar Pradesh, India (altitude 1829 m). Its fruit, which have soft flesh and rind that split at maturity, are used in soups and stews, and the seeds are roasted and eaten. PI 414723, PI 371795, and the related Ames 20219 and progeny 92528a were resistant to California and Florida isolates of papaya ringspot virus watermelon strain (PRSV-W). Plants were either symptomless, or they exhibited local lesions, systemic necrosis, or systemic spots. Resistance to PRSV-W is conditioned by a single dominant gene. Allelism with Prv1 (PI 180280, Rajkot, Gujarat, India), Prv2 (PI 180283, Bhavnagar, Gujarat, India), Nm (`Vedrantais, Fance), and a recently described gene for PRSV-W resistance in PI 124112 (Calcutta, India) is yet to be determined.

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