New Species Bred By Crossing Cukes, Melons

Scientists have, for the first time, crossed a cucumber with a melon--a breakthrough that could give both plants more genetic resistance against diseases and pests.

Agricultural Research Service botanist Joseph Kirkbride, a world expert on the genus Cucumis (Cucurbitaceae), named and described the new hybrid Cucumis x hytivus.

This new species was developed by crossing a cucumber, Cucumis sativus, with a melon, Cucumis hystrix.

Kirkbride, who works at the ARS Systematic Botany and Mycology Laboratory, Beltsville, Md., collaborated with Chen Jin-Feng, professor of horticulture at Nanjing Agricultural University, Nanjing, China, on naming and describing the new hybrid.

According to Kirkbride, many cucumbers and melons are susceptible to a number of fungal, bacterial, viral and insect diseases that reduce both their yield and quality. Studies are underway at several ARS laboratories to discover resistance to many of these costly diseases.

With the new cucumber/melon cross, researchers can breed improved cucumbers and melons. It will serve as a bridge for shuttling useful genes--especially those for disease resistance--between the two.

Although cukes and melons belong to the same botanical genus, cross-breeding them by conventional methods had never been possible according to Kirkbride. Cucumis is a very diverse plant genus with 32 species. The genus includes two crops of major economic importance, cucumbers and melons (honeydew and cantaloupe), as well as gherkins and cassava melons.

Chen developed the new synthetic species Cucumis x hytivus by doubling the chromosomes of the hybrid using traditional breeding techniques.

ARS is the chief research agency of the U.S. Department of Agriculture.

Scientific contact: Joseph H. Kirkbride, Jr., ARS Systematic Botany and Mycology Laboratory, Beltsville, Md.; phone (301) 504-9447, fax (301) 504-5810, joe@nt.ars-grin.gov.