关键词: 雷竹, 分株系统, 地下茎, 形态特征, 生物量积累, 芽库构成

Abstract: This study was aimed to clarify the mechanisms underlying the construction and maintenance of bamboo population, explore the process of bamboo population construction from a single mother bamboo to ramet system, and then construct bamboo population. We analyzed the growth characteristics of rhizome morphology, biomass and bud bank of bamboo seedlings in a pot experiment with mother bamboo (Phyllostachys praecox C. D. Chu et C. S. Chao ‘Prevernalis’, a bamboo species for small-diameter shoots) at different ages and mulching bamboo forest soils. The average rhizome length (666.58±111.75 cm·pot^-1) and the average number of rhizome internode (342±44 ind·pot^-1) in 2-year-old mother bamboo seedlings were significantly higher than those in 1-year-old mother bamboo seedlings (354.25±136.64 cm·pot^-1 and 216±88 ind·pot^-1), while average rhizome diameter (0.77±0.07 cm) was lower than that of the 1-year-old mother bamboo seedlings (1.07±0.12 cm). For the rhizome biomass accumulation, 1-year-old mother bamboo seedlings allocated more biomass to rhizome, while 2-year-old mother bamboo seedlings allocated more to root. The number of bud bank of 2-year-old mother bamboo seedlings was higher than that of 1-year-old mother bamboo seedlings. The number of total buds and dormant buds reached 342±43 and 277±42 ind·pot^-1 respectively, while the number of 1-year-old mother bamboo seedlings was only 216±80 and 187±69 ind·pot^-1. Those results indicated that the thicker the bamboo rhizome, the less differentiation of rhizome bud, and that the greater the number of rhizome internode, the higher the rhizome biomass. The rhizome bud bank mainly consisted of dormant buds. The lateral buds of slender bamboo rhizome with many rhizome internodes had larger bud reserves. The lateral bud germination was mainly rhizome buds, and the quantitative characteristics of shoot bud differentiation did not show obvious regular changes. As a single ramet, mother bamboo was efficient in rhizome regeneration by expanding and propagating into ramet system, increased the number of lateral buds which differentiated into rhizome buds, and achieved a rapid growth of rhizome length. Such characteristics were also good for total bud amounts of bud bank, especially the large-capacity reserve of dormant buds, providing good basis for the further propagation of the ramet system.

Key words: Phyllostachys praecox C. D. Chu et C. S. Chao ‘Prevernalis’, ramet system, rhizome, morphological characteristic, biomass accumulation, bud bank composition.