Submitted to: HortScience
Publication Type: Germplasm Registration
Publication Acceptance Date: April 20, 2011
Publication Date: October 25, 2011
Citation: Staub, J.E., Simon, P.W., Cuevas, H.E. 2011. USDA, ARS EOM 402-10 high B-carotene cucumber. HortScience. 46:1426-1427. Interpretive Summary: Strong evidence suggests that diets rich in B-carotene (synom., pro-vitamin A; precursor of retinol) and other carotenoids (e.g., lycopene) can prevent the onset of some chronic diseases such as phrynoderma, anemia and certain cancers (e.g., prostate). The United States recommended dietary allowance (RDA) of retinol is 1 mg/day equivalent (i.e., approximately 6 mg of B-carotene equivalents). However, practical implementation of this recommendation is often not achieved in rural and underdeveloped areas of the world. As a result, vitamin A deficiency (VAD) is a major public problem in over 75 countries in the developing world. The white to green-colored mesocarp of commercial cucumber has been of culinary importance to humans for millennia. Several major types of cucumber are cultivated worldwide, including American processing and fresh market classes, European gherkin and glasshouse types, the German Schalgurken, the Mideast Beit Alpha form, and Oriental trellis (burpless) varieties. Although, cucumber has a narrow genetic base (i.e., low diversity), plant introductions (i.e., Pls) have contributed significantly to the improvement of all major market types. In 1987 a PI was collected in China that produces fruit with an orange interior that is relatively high in B-carotene. This PI was crossed to commercial cucumber (low in B-carotene) to produce the high B-carotene cucumber line EOM 402-10. Line EOM 402-10 is being made available to U.S. cucumber breeders to supply a source from which they may develop elite germplasm possessing high levels of B-carotene as a natural source of vitamin A the human diet. Incorporation of B-carotene from this line into commercial cucumber can be used to supplement vitamin A in commercial cucumber, thus allowing the producer to be more competitive in the global market by supplying a unique and novel product in potentially many different cucumber market classes.
Technical Abstract: A high B-carotene cucumber (Cucumis sativus var. sativus L.) line EOM 402-10 is being released. This line was derived from a cross between the "Xishuangbanna gourd" (XIS; Cucumis sativus var. xishuangbannanesis Qi et Yuan; 2n = 2x = 14) that bears orange fruit and the non-orange-fruited cultivated cucumber (2n = 2x = 14). XIS is cultivated in southern Yunnan province, P.R. China and is an exotic introduced into the U.S. between 1987 and 1988 (PI 509549). The fruit of XIS possess an orange-colored endocarp/mesocarp (due to the presence of B-carotene) and after self-pollination of the initial F1 produces progeny segregating for yellow and orange internal fruit (mesocarp/endocarp) color. Individual selected plants were self-pollinated and those bearing fruits with orange interiors were retained for further breeding. Selection for uniform orange pigmentation and inbreeding was continued for four generations to produce an S4 line designated 'EOM 402-10' (in 2007) that produced true-breeding orange-pigmented fruit (i.e., orange flesh color). Although sibling selections ('EOM 402-1-9') demonstrated varying relatively concentrations of B-carotene (3 to 8 ug g-1 of fresh tissue), 'EOM 402-10' possessed the best fruit shape and internal quality of its high carotene counterpart lines. It is a U.S. Pickling market type (moderately warty, no endocarp/mesocarp pigment, fruit ~ 13 to 17 cm long and 3.5 to 4 cm wide) with Chinese type XIS (extremely warty, orange pigmented fruit ~ 34 to 40 cm long and 3-4 cm wide). The mean mesocarp B-carotene content of mature EOM 402-10 greenhouse grown fruit is 2.72 ug g-1 of fresh tissue, which is significantly higher than green (0.02 ug g-1), and white (0.01 ug g-1) mesocarp of U.S. pickling cucumber. Likewise, the endocarp a-carotene content of EOM 402-10 (3.05 to 7.54 ug g-1 of fresh tissue) is higher than U.S. pickling cucumber (0.16 - 0.37 ug g-1 of fresh tissue) and has no visibly discernible color. Line EOM 402-10 is being made available to U.S. cucumber breeders to supply a source from which they may develop elite germplasm possessing high levels of B-carotene as a natural source of vitamin A the duman diet. This germplasm will also be useful directly in breeding and genetic studies.