Studies On The Hormones And Nutrition Dynamics Of Phyllostachys Glauca McClure During Flowering Period

Phyllostachys glauca McClure belongs to Phyllostachys of Gramineae, which is an important economic ornamental bamboo specie in northern China. However, large areas of bamboos began to bloom, from Shandong to Beijing, in spring of 2014, which caused serious damages to the local economy and landscape. Therefore, it is significant to study the ruel of the floral formation and control the mechanism of bamboo’s flowering to promote the bamboo renewal after flowering.Our study site located in Linqing city, Shandong province. The flowering types were divided and the flowering rules of the early flowering period were explored by observing the biological characteristics of bamboos during its flowering. Through the cutting experiment, for different ages and types of bamboos, the hormones including IAA, ABA, GA₃, Zr and nutrients in different organs at different flowering stages were measured, aiming at exploring the variation regularity of hormones and nutrients of bamboos of its early flowering period. The main conclusions are as follows:1. Phyllostachys glauca McClure was in the type of flowering wholly. It had obvious variation in appearance when flowering, for example, the color of leaves became yellow. We divided bamboos into four types according to their flowering characteristics: old bamboos with all flowers and no leaves; new bamboos with all flowers and no leaves; bamboos with half flowers and half leaves; bamboos with all leaves and no flowers.2. The flowering period of bamboos was from mid-March to July. We divided period to five stages. Early stage was from mid-March to late April. Full-bloom stage was from early May to early June. Late stage was from mid-June to last-July. Final stage was after last-July. Bamboos also bloomed in mid-late October.3. During different flowering periods, the hormones showed various changing trends:（1） The content of IAA had no obvious correlation with ages and types.（2） ABA had obvious relation with ages: 3a > 2a > 1a, and also the types: all flowers and no leaves > half flowers and half leaves > all leaves and no flowers;（3） The GA₃ and Zr were always in a low level, and they had no obvious difference in different flowering stages. The average GA₃ and Zr in rhizomes were the highest in 2a, but the GA₃, Zr in leaves and Zr in flowers had nothing to do with ages. The GA₃ in flowers decreased as the ages increased. The levels of GA₃ and Zr in flowers were influenced by types, all leaves and no flowers > half flowers and half leaves > all flowers and no leaves. The hormones of different ages of flowering bamboos showed that: leaves > flower > rhizomes. The IAA and ABA in leaves of flowering bamboos were all lower than that of non-flowering bamboos, but the ABA in rhizomes of flowering bamboos was higher. The content of GA₃ and Zr in leaves of non-flowering bamboos were similar, but GA₃ in rhizomes of flowering bamboos was lower than Zr in rhizome of non-flowering bamboos. Compared to non-cutting bamboo forest, the different hormones in leaves and rhizomes of bamboos in cutting bamboo forest were higher.4. The amount of nutrient elements in Phyllostachys glauca McClure were Ca > Mg > Fe > Al > Cu. The contents of Cu in leaves, culms and rhizomes were similar. The contents of Mg, Fe and Al in leaves were 3 times higher than in culms and rhizomes. The contents of Ca in leaves were about 5-10 times higher than in culms and rhizomes. Different nutrient elements of flowering and non-flowering bamboos had similar change rule. The contents of Mg, Fe decreased, while the contents of Ca, Al, Cu increased during flourishing period, and the contents of Mg, Fe increased while the contents of Ca, Al, Cu decreased after flourishing period. However, the contents of nutrient elements in organs of non-flowering bamboos were higher than the ones of flowering bamboos. The nutrient elements in organs of bamboos were not related to ages and types.