Development and assessment of F1 hybrids in Romanesco cauliflower

Summary

In a trial of Romanesco cauliflower inbred lines, hybrids and controls, differences between mean performance of hybrids and their mid-parents demonstrated heterosis, with F₁ hybrids producing larger curds on larger plants with earlier maturity in most crosses. In F₁ hybrids, the small increases in curd depth, together with reduction in looseness and the overall slight improvement in curd quality, were attributed to the ability to harvest hybrid curds at earlier maturity than their inbred parents. The ability to increase the marketable yield is a prime benefit of F₁ hybrids in Romanesco cauliflowers. An effect of early test crossing was to improve seed production, both in inbred lines and hybrids. With a wider diversity of inbred lines, early testing generally would be advantageous and would also provide an opportunity to screen for inbred lines with strong self incompatibility as potential F₁ parents.