The effect of maturation, protein content, and ploidy on phosphorus metabolism of potato cultivars and Phureja-Tuberosum hybrids

Abstract

Selection for high protein potatoes may be influenced by maturity level at harvest. as well as by genetic capacity. The phosphorus metabolism provided a clue as to physiological maturity. We determined the major phosphorus compounds present in tubers of named cultivars sampled at weekly intervals during the growing season. We also assessed the phosphorus compounds associated with mature tubers of twelve Phureja-Tuberosum hybrid lines varying widely in protein content, and in ploidy. High levels of organic phosphorus, nucleic acid phosphorus, and lipid phosphorus were characteristic of immature tubers. These values declined to a mid-season plateau that was maintained to harvest. Much greater variability in phosphorus balance was found in the hybrid clones analysed than in named cultivars. In some cases high protein levels were clearly associated with delayed maturity of hybrid lines. Other clones appeared to exhibit greater capacity for protein synthesis in the maturing tuber.