Selection and characterization of a new strain with thin blades and high-temperature resistance in Neoporphyra haitanensis

To select a new strain of Neoporphyra haitanensis with thin blades and high-temperature resistance, an intraspecific hybridization of a cultivated strain (WT-bo, male) and improved strain (HR-5, female) in N. haitanensis was carried out, and then a new strain qF-15 was isolated from the offspring based on heat stress and characteristics analysis. After being cultured for 40 days, the mean thickness of the blades was 22.3 mu m in qF-15, which was 9.7% and 8.3% lower than that of WT-bo and HR-5, respectively; the total phycobiliprotein content was 122.9 mg/g in qF-15, which was 41.6% and 5.9% higher than that of WT-bo and HR-5, respectively. After being cultured for 45 days, the mean length of the blades was 70.4 cm in qF-15, which was 2.6- and 1.6-fold of that of WT-bo and HR-5, respectively. After being cultured for 7 days at 30 degrees C, the survival rate of conchospore germlings was 25.9% in qF-15, which was 439.6% and 223.8% higher than that of WT-bo and HR-5, respectively. The blades were cultured for 25 days at 23 degrees C and then cultured for another 20 days at 30 degrees C. Plenty of cells died in the blades of WT-bo, while only a little of cells died in the blades of HR-5 and qF-15. After the conchocelis-inoculated shells experienced the process of high temperature and shrunk of light, the time for the emergence of a lot of conchosporangial branch was about 20 days for the three strains. In summary, qF-15 was characterized by thin blades, high-temperature resistance of conchospore germlings and blades, fast growth, high phycobiliprotein content, and fast differentiation rate of conchocelis-inoculated shell, and it is expected to be applied in production and cultivation.