Inheritance of fruit color in surinam cherry (Eugenia uniflora L.) -: A preliminary study

Surinam cherry (Eugenia uniflora L.) is commonly used in Florida, Hawaii, and in many tropical regions of the world as an ornamental shrub. The fruits are also commonly eaten fresh or used in cooking, although some fruits may have a somewhat unpleasant resinous flavor. Most plants bear fruits that are red to red-orange in color. Plants bearing dark-colored (maroon, purple or "black") fruits have been reported, but are uncommon. Ten grafted plants of a clone of a dark-fruited, non-resinous selection ('Zill Dark') of Surinam cherry were purchased from Zill High Performance Plants and planted on the Florida Southern College campus in the mid 1990s. Four of these plants were planted in an isolated area of the campus, away from any red-frulted plants. Surinam cherry plants appeared to self-pollinate easily, and these isolated plants set dark-colored fruits the next year after planting. In spring 1999, 150 seeds were extracted from the fruits and planted in community pots in the FSC greenhouses. Most of the seeds germinated within one month's time and the seedlings were repotted into individual 10 centimeter (4 inch) pots. Several months later, the seedlings were potted up into 3.78 liter (1-gallon) containers where they remained for 2 1/2 more years. Only a few plants came into bloom during that time. In spring 2002, the surviving seedlings (120) were potted up into 11 liter (3-gallon) containers, spaced in full sun conditions, and placed on drip irrigation. Plants were fertilized with Sierra 17-6-10 & minors (89 month) slow-release fertilizer. In central Florida, blooming of Surinam cherry tends to be asynchronous except in the early spring of the year, when most plants bloom all at the same time. In spring 2003, fruits were collected and sorted by the color of the mature fruit. Of the 120 plants remaining from the initial planting, 88 had dark (maroon or black) fruits, 27 had red or red-orange fruits and 5 did not bear any fruit. From these data, it appears that the 'Zill Dark' cultivar of Surinam cherry is heterozygous for the gene for mature fruit color with the dark (maroon or black) phenotype dominant over red in the classic Mendelian ratio of 3:1. It also appears likely that a single gene determines fruit color in Surinam cherry.