NUMBER OF LETHAL LOCI AND LETHAL EQUIVALENTS IN WILLOW, SALIX-VIMINALIS

Two methods of estimating lethal equivalents have been examined in thi s paper: A combinatorial method (COMB) and a method developed by MORTO N, CROW and MULLER (MCM). Both methods produce similar estimates of le thal equivalents. However, the 2 methods differ in 2 respects: (1) COM B makes inferences to particular individual(s) in the population, whil e MCM makes inferences to the entire population; and (2) COMB estimate s the number of lethal loci which is translated into lethal equivalent s, while MCM directly estimates lethal equivalents. In a previous pape r KANG et al. (1992) failed to recognize the second difference between COMB and MCM, and overestimated lethal equivalents in Salix viminalis . The revised estimate of lethal equivalents using COMB is 1.8, which is similar to that (1.69) estimated by MCM previously.