Study on high-temperature-resistant and high-yield Laminaria variety Rongfu

Hybridization of gametophytes, continuous self-crossing and targeted selection were utilized to breed a new Laminaria variety. After five-generation selection breeding, the new variety Rongfu was obtained. Its male parent Yuanza No.10 was the high-yield cultivation variety, and its female parent was variety Fujian which could tolerate relatively high seawater temperature. Yuanza No.10 and Fujian were different but complement in their morphological characteristics and biological habits. Variety Rongfu was bred through their hybridization which exhibited high-yield potential and high seawater temperature tolerance. The results of traits evaluation in consecutive years showed that Rongfu attained higher yields by 24-27% compared to the control (widely used commercial variety) and also contained considerable amounts of iodine, mannitol, and algin. When seawater temperature was 18-21A degrees C, the blade growth of Rongfu was maintained and tissue loss by abrasion was significantly lower than the control. Since the adoption of variety Rongfu in 2001, its cultivation areas have been extended to Shandong, Fujian and Guangdong province and have reached 14,133 ha currently, i.e., almost one-tenth of the total cultivation areas of Laminaria in China. The results of Random Amplified Polymorphic DNA analysis showed that the relationship between Rongfu and other cultivation varieties in China was very close.