Somatic embryogenesis and plant regeneration from leaf tissues and anthers of Pennisetum purpureum Schum.

Summary Twenty families of the lobster, Homarus americanus, were reared at 10°, 15° and 20°C with and without bilateral eye-stalk-ablation. At 20°C both eye-stalk-ablated and non-eye-stalk-ablated lobsters from each family were assigned to one of two dietary treatments: 1) frozen whole brine shrimp, or 2) a diet of cheap, local constituents. The means of growth traits improved while viability decreased with increasing temperature. The ablation technique shows promise since improved performance for growth was apparent in eye-stalk ablated lobsters, but mortality was greater. Important genetic variation of all traits was found in each of the environments tested. The genetic correlations between growth traits were reinforcing, but the correlations between growth and viability traits were mainly negative. Ease and reliability of measurement should be considered when choosing growth traits in any artifical selection program.