Genetic analysis of within family variation in true seed crop of potato (Solanum tuberosum L.)

A study was conducted on 72 families from 18 x 4 factorial mating design to evaluate them for within family variation for tuber yield, its components and general impression in seedling (transplanted) and seedling-tuber potato crops. Plant (genotype) to plant (genotype) variation within a family for tuber yield was affected by the choice of males, females and their specific combinations, whereas no such effect was observed for general impression. For within family variation of tuber number and average tuber weight, choice of parents and crosses was more important in the seedling than in the seedling-tuber crop. Nature of gene action was predominantly non-additive for within family variation of various characters. A comparison of combining ability effects for progeny means and within family variations showed the possibility of having parents and crosses which may result in progenies with high tuber yield and an acceptable level of uniformity for various tuber characters as determined by general impression. For identifying such TPS populations, good general combiners for progeny mean of tuber yield should be intercrossed and families subjected to progeny selection for tuber yield, general impression and within family variation for general impression. ‘PJ376 × EX/A680-16’ was identified as a promising cross which may result in a true potato seed population suitable both for seedling and seedling-tuber crops.