Two tomato inbreds (one advanced greenhouse line, P1=Ohio ICR.9 and one frost resistant line, P2=Ohio 4013-3) and F1, BC1, BC2 and F2 progeny were examined for growth and development during December and January to determine inheritance of biomass characters. Two-week-old seedlings from each generation (8 from the P1, P2 and F1; 32 from the BC1 and BC2; and 64 from the F2) developed over a 9-week period at 2 different night temperatures (17 and 12 C) and light levels (natural light and 30% shade, 5 days/week). The F1 generation had the highest leaf area and total dry weight means followed by the BC1 and P1 generations. The variance components for leaf area and total dry weight accumulation were: Ve = 120,300 and 2.63; Vp = 553,618 and 12.46; Va = 127,475 and 3.65; and Vd = 305,843 and 6.18, respectively. Both traits are highly heritable, having a broad sense heritability of 0.78 and 0.79 for leaf area and total dry weight, respectively. However, because narrow sense heritability is low, 0.23 and 0.30, respectively, improvement in biomass accumulation will be more difficult.
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