Molecular and morphological character inheritance in hybrids of Alaria esculenta and A. praelonga (Alariaceae, phaeophyceae)

Hybridization of Alaria escalenta and A. praelonga (Phaeophyceae. Laminariales, Alariaceae) resulted in successful and healthy progeny. Morphological characters, relative growth rates and Rubisco spacer sequences of hybrids were compared with the parental plants. The results show that hybrids inherit the morphological characters from the A. praelonga gametophytes, indicating that these characters are not sex-linked and are dominant. The relative growth rates were significantly different among the F₁. with the A. esculenta self-cross progeny showing the fastest relative growth rate for length compared to the other cross combinations. The A. praelonga self-cross progeny also grew significantly faster than the progeny from hybrid crosses, which did not differ significantly from each other. The A. escalenta and A. praelonga self-cross F₁ did not differ significantly in relative growth rate for width. Hybrid progeny showed a significant slower relative growth rate for width, compared to the A. esculenta self-cross progeny but did not differ significantly from each other. A comparison of Rubisco spacer sequence alignments showed that the Rubisco spacer is inherited via the female gametophyte in Alaria. which is in accordance with results found in other members of the Laminariales. Chloroplast DNA is probably inherited maternally in all Laminariales. Analysis of the Rubisco sequences revealed one mutation in the large subunit in the female A. esculenta x male A. praelonga hybrid. Effects of this mutation on the amino acid coded are discussed.