Registration of LN‐183, Nondormant Cuphea lanceolata Germplasm

LN-183 (Reg. no. GP-4, P1 574384) is a nondormant, openpollinated population of Cuphea lanceolata Ait. LN-183 was developed from LN-148 after three cycles of recurrent mass selection for decreased seed dormancy. LN-183 was developed at Oregon State University and was officially released by the Oregon Agricultural Experiment Station in 1992. LN-148 was developed by intermating (LN-61-ND)S5/(LN-68)S5 FI plants. Although wild populations of C. lanceolata exhibit some seed dormancy, the dormancy of this species is less severe than that of many other species of Cuphea (1,2,3). The postharvest seed dormancy of wildtype C. lanceolata germplasm ranges from 4 to 16 wk, while the embryo dormancy ranges from 1 to 8 wk (1,2). Seed of C. lanceolata can be germinated by removing the seed coats once embryo dormancy is broken. LN-183 lacks postharvest seed coat or embryo dormancy. The germination percentages of freshly harvested LN-183 seed usually exceed 80%. Other C. lanceolata lines and populations must be stored for a minimum of 4 wk before these germination percentages can be achieved (1,2,3). Many species of Cuphea need several months or years of storage before they germinate. (LN-61-ND)Ss is a nondormant inbred line of C. lanceolata. This line originated from the wild open-pollinated population LN-61. Freshly harvested seed of LN-61 did not germinate, but a random LN-61 S3 line with no postharvest seed dormancy was observed and selected. Sublines of this line were developed and selected for two additional generations and culminated in the development of the nondormant inbred line (LN-61-ND)S5. The vigor of (LN-61-ND)S5 was severely depressed by inbreeding, and this line was unusually hard to propagate sexually. This problem was overcome by crossing it to a partially nondormant inbred line (LN-68)S5 to restore vigor and create a narrowbased open-pollinated population LN-148. Three cycles of recurrent mass selection for nondormancy were subsequently completed within LN-148. The first 30 germinants among 600 seeds were selected each cycle; 100% of the selected progeny lacked postharvest seed dormancy. The open-pollinated population LN-183 was created by intermating the progeny from the last cycle of selection. LN-183 combines vigorous growth with a lack of postharvest seed dormancy. LN-183 can be distinguished from undomesticated C. lanceolata germplasm by the lack of postharvest seed dormancy; however, the growth habit, seed shattering, and other traits of LN-183 are typical of undomesticated germplasm (4). The seed oil, caprylic, capric, lauric, myristic, palmitic, oleic, and linoleic acid contents of LN-183 harvested at Corvallis, OR, in 1991 were 285, 8, 836, 21, 21, 32, 29, and 46 g kg", respectively. These percentages are typical of wildtype C. lanceolata germplasm (5). The 1000-seed weight of the 1991 harvest of LN-183 was 2.9 g. This germplasm is indeterminate with mature heights greater than 0.75 m and often exceeding 1.5 m. LN-183 is a source of germplasm for breeding nondormant germplasm and cultivars. Seed of LN-183 can be obtained by writing to the corresponding author. Please acknowledge the source of this germplasm when developing additional germplasm, cultivars, or hybrids.