Variability of Protoplast‐derived Potato Clones1

Abstract

Sixty‐five selected clones of potato (Solanum tuberosum cv. Russet Burbank) regenerated from mesophyll protoplasts (protoclones) were analyzed for variability under field conditions. Protoclones were planted in randomized complete blocks replicated six times. During the growing season and after harvest a total of 35 characters were measured for each clone and compared with similar measurements from the parental ‘Russet Burbank’ and with another virus‐tested clone of the cultivar. Statistically significant variation was found for 22 characters, variation not amenable to statistical treatment in 4 characters, and no variation in 9 characters. Protoclones were nearly equivalent in most characters to both Russet Burbank standards. However, quantitative data showed that each protoclone differed from Russet Burbank in some trait(s). Variation ranged from a minimum of one character in three protoclones to a maximum of 17 characters in one protoclone. Differences in vine morphology, tuber yield and composition, maturity and flowering were observed. Some of the variability found should be an improvement over normal traits found in the normal cultivar. Further testing is necessary to determine both the stability of and the effect of the environment on this variability. However, the data do suggest that for potatoes, protoplast regeneration may offer a new means of generating variability of potential use for crop improvement.