Characterization of the novel hybrid cultivar E25 of Saccharina japonica in the northern farming region of China
Li Su, Ti Feng Shan, Jing Li, Su Qin Gao, Shao Jun Pang#, Xiao Fei Leng, Yan Zhang, Ming Fu Zhang & Hong Tao Gao
Use of cultivars with certain agronomical traits has been throughout the development history of kelp Saccharina japonica farming in China. Pursuit of high yield had been on top of all the parameters. However, in recent years, demand for better blade quality has steadily become intensive, especially in the northern farming region of this country. In this article, we report a newly bred, intraspecific hybrid E25 (as designation code), of its biological features and its applicability as a potential cultivar in the related farming region. A fully grown sporophyte of E25 could reach 4–5 m in length, 0.6–0.8 m in width, and 3–5 kg in fresh biomass depending on the farming zones and growing density within ca. 7-month cultivation period from November to May–June of next year. Unlike most of the cultivars or naturally grown sporophytes, sporophyte of E25 lacks fascia in the middle of the strip and possesses smooth blades. It has thicker ruffled undulate margins on both longitudinal sides and relatively low water content in its blade. Due to its much higher chlorophyll a content, blanched product is greener than most of the other cultivars, much favored by the processing industry. Seedling production of E25 relays on a pair of vegetatively propagated unialgal male and female gametophytes. High polymorphic microsatellite markers could accurately identify its uniformed genotype and distinguish it from other conventional cultivars. The first filial sporophytic generation of E25 (E25-F1) maintains the same yield level as its parent, reaching 23–25 kg m−1 cultivation rope, but with larger deviations in individual sizes as reflected by its higher coefficient of variations (CV).