Prelimary study of segment culture of Kappaphycus alvarezii

We discussed the effects of induction temperature, cutting length and cutting way (transected cutting and inclined cutting by 90 and 45 degree angles with algae body on the vertical axis, respectively) on growth and bud formation of Kappaphycus alvarezii explants. The results show that under the test conditions, the suitable growth temperature for K.alvarezii was 15~25 ℃, the optimum temperature was 20 ℃. The effects of induction temperature, cutting length and cutting way for bud formation of K. alvarezii explants were significant, and interactionamong each factor was very significantly different (P0.01). The cultivationat higher temperature obviously promoted the budding, and the average number of buddingsat 25 ℃ was more than thatat 20 ℃ (P0.01). Transected cutting promoted the budding of explants, and withthe same cutting length, the average number of buddings in crosscutting group was more than that in inclined cutting group (P0.01). Short cutting helped to increase the number of buddingsby the same cutting way, 1 cm group obtained significantly more buddings than 3 cm and 5 cm groups (P0.01). Besides, the individuals had the most average number of buddings in 1 cm group at 25 ℃ (average 1.50). Different cutting lengths had obvious effect on the budding position. The explants in 1 cm and 3 cm groups formed regeneration buds on the section area, while those in 5 cm group formed regeneration buds on the section area and newborn buds on the cortex.