CUPHEA VISCOSISSIMA MUTANTS WITH DECREASED CAPRIC ACID

The range of medium-chain oils produced by Cuphea viscosissima Jacq., a naturally rich source of capric acid (10:0), can be broadened by dev eloping lines with increased caprylic (8:0), lauric (12:0), or myristi c (14:0) acid. Our objectives were to (i) describe the inheritance of a series of mutants with decreased 10:0 (CPR-1, CPR-2, CPR-4, CPR-5, a nd CLM-1) and (ii) develop lines with fatty acid compositions differen t from other mutant lines. CPR-1, CPR-2, and CPR-5 had similar to 310 g kg(-1) less 10:0 than the wild type (WT), whereas CPR-4 had 62 g kg( -1) less 10:0 and CLM-1 had 50 g kg(-1) less 10:0 than the wild type. We assayed the fatty acids of 100 progeny from 10 F-2 populations segr egating for one or more mutations. CPR-1, CPR-2, and CPR-5 produced th ree non-overlapping capric acid classes and segregated as single incom pletely dominant mutations. CPR-1 x CPR-2 and CPR-1 x CPR-5 F-2 progen y had continuous 8:0 and 10:0 distributions. The CPR-1 x CPR-5 cross p roduced several F-2 progeny with atypical 8:0 and 10:0 phenotypes, whi le the CPR-1 x CPR-2 cross produced no F-2 progeny different from eith er parent. CPR-I and CPR-2 seem to be allelic mutations affecting the cpr locus. CPR-(5) could be an allele of the cpr locus or of a locus t ightly linked to cpr. CPR-4 x WT and CLM-1 x WT F-2 progeny had contin uous 10:0 distributions. CPR-1, CPR-4, and CLM-1 seem to be non-alleli c mutations. VS-320, an F-3 line developed from the CPR-1 x CLM-1 F-2 population, had 334 g kg(-1) 8:0 and 396 g kg(-1) 10:0. VS-321, an F-3 line developed from the CPR-4 x CPR-5 F-2 population, had 247 g kg(-1 ) 8:0 and 361 g kg(-1) 10:0. The 8:0 or 10:0 contents of these lines a re lower or higher than previously reported for C. viscosissima.