Ej. De Paula et al., Strain selection in Kappaphycus alvarezii var. alvarezii (Solieriaceae, Rhodophyta) using tetraspore progeny, J APPL PHYC, 11(1), 1999, pp. 111-121
A brown strain of Kappaphycus alvarezii from the Philippines produced tetra
spores in the summer and autumn (December 1995 to May 1996) in cultivation
experiments in the sea at Ubatuba, Sao Paulo State, Brazil. In vitro tetras
pore release and germination experiments showed a mass mortality two to fou
r days after release. Only 20 plants derived from tetraspores were grown su
ccessfully for over a year in the laboratory. Large differences in morpholo
gy, colour, size and growth rates were observed amongst these plants. The i
ndividual plants differed from one another in one or more characteristic. D
ifferences appeared in the early developmental stages and persisted through
time. After ten months, the plants that grew best in laboratory culture we
re transferred into the sea, but the others remained very small (3 to 5 mm)
, even after two years. In the sea, the plants also showed individual diffe
rences in their ability to survive and grow. These results emphasise the po
tential of the tetraspore progeny for strain selection in K. alvarezii. The
results also suggest that the tetrasporophyte used in these studies is of
hybrid origin.