Location: Crop Improvement and Protection ResearchTitle: Suppression of Cucurbit chlorotic yellows virus accumulation in melon breeding line MR-1 under natural infection in Imperial Valley, California
Submitted to: Cucurbit Genetics Cooperative Report
Publication Type: Research Notes
Publication Acceptance Date: 9/4/2020
Publication Date: 9/14/2020
Citation: Tamang, P., Wintermantel, W.M., McCreight, J.D. 2020. Suppression of Cucurbit chlorotic yellows virus accumulation in melon breeding line MR-1 under natural infection in Imperial Valley, California. Cucurbit Genetics Cooperative Report. 42:26-29.
Technical Abstract: Cucurbit chlorotic yellows virus (CCYV) infection of melon was observed for the first time in the New World in Imperial Valley, California in 2018, where it co-infects melon with Cucurbit yellow stunting disorder virus (CYSDV). Both viruses are transmitted exclusively by the sweet potato whitefly. Melon line MR-1 was reported in the literature as one of five putative sources of resistance to CCYC. We evaluated its reaction to CCYV and CYSDV in a naturally co-infected field test in Imperial Valley, California in Fall 2019. We assessed symptom expression (foliar yellowing) and titers of the two viruses (copies/µl). MR-1 exhibited extensive foliar yellowing that could have been induced by CYSDV alone, as it had been reported to exhibit no or only faint symptoms in a controlled inoculation greenhouse test. Virus content was, however, low, 1 % of the level in susceptible ‘Top Mark’ compared with the titer in PI 313970 that was 136 % of ‘Top Mark’. CCYV titers in the four melon lines evaluated were 7 to 1.8E+07 fold greater than CYSDV titers.