CucCAP scientists genetically map novel sources of resistance to cucurbit downy mildew in watermelon

Watermelon crops are increasingly threatened by infection by cucurbit downy mildew. While there are limited sources of disease resistance within cultivated watermelon, Citrullus amarus can be a valuable source of resistances. CucCAP scientists performed disease resistance screening and whole genome resequencing of 122 C. amarus accessions.  Genome wide association analysis of these materials identified several marker-trait associations and candidate genes, providing potential resources for genomics-assisted breeding for resistance to CDM in watermelon.

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CucCAP scientists examine mechanisms of watermelon resistance to viral infection

Watermelon production in the U.S. and around the world faces serious threats by viral diseases, including aphid-transmitted potyviruses: papaya ringspot virus (PRSV) and zucchini yellow mosaic virus (ZYMV). In a recent study, a CucCAP team examined expression of anti-microbial/anti-viral, ribosome-inactivating proteins (RIPs) in watermelons in response to inoculation with PRSV.  The PRSV-resistant citron watermelon (Citrullus amarus) exhibited high RIP expression, versus low expression in plants of the susceptible, cultivated “Charleston Gray” watermelon. This finding may offer additional genetic and genomic resources for improving potyvirus-resistance in watermelon cultivars.

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