Studies On The Nutrition And Hormones Dynamics Of Phyllostachys Praecox CV.Prevernalis During Flowering Period As Well As The Mechanism Of Floral Formation

Phyllostachys praecox cv. Pervernalis has the virtue of sprouting earlier, longer producing time, delicious taste, it is one of the popular edible bamboo shoots. In recent years, however, there are more and more Phyllostachys praecox cv. Pervernalis which begin to flower, and their products decrease obviously, some fall down over 40-70 %, some wholly decay to death, the producer lost seriously. It is significant to study the floral formation reason of bamboo and research to delay the florenscenct time.Up to now, emphases on studying the floral formation reason lie on analyzing historical materials of bamboo flowering, observing the flowering phenomena, investigating the bamboo forest, they provided various theories such as growth periodic theory, nutrition theory, individual variation theory, free group theory, and so on. Different researchers put forward different methods to prevent the flowering of bamboo and renew flowered bamboo, but their effects are not very satisfactory.This project study the correlation between flowering and inner hormones and nutrition from the rule of composition and ratio variation during flowering, set up the hormones and nutrition adjusting system, instruct to formulate the treatments to postpone the flowering time.Through research, we find the variation of the nutrition and hormones are closely related to the outside changes of the flowering bamboo:1 , In leaves, branches and roots, large amount nutrition elements, including N and P and K, keep relatively stable or increase a little in no flowering bamboo, but in flowering bamboo, they reduce obviously, the largest degree is up to 60 % (K).2, During flowering time in September, elements content in the flowering bamboo, including N, P, K, Fe, Zn, and Cu in branches and roots, is lower than that in no flowering bamboo.3> Analyzing the average value, the P content in flowering bamboo leaves is higher than that in no flowering bamboo, and P has the function of promoting the bamboo to flower, but it is contrary in roots. There are two different reasons. One is the P accumulated in roots transports upward to the branches and leaves. The result is that the level in branches and leaves is even higher than in roots. The other is the ability which the flowering bamboo absorbs P nutrition turns to decrease, P level in flowering bamboo is lower than that in no flowering bamboo.4, The content of ABA increases along with the flowering process. ABA has the function of promoting plant organs to drop. The manifestations in bamboo are the leaves falling off, whole bamboo flowering to death. Considering the variation scope of ABA in different organs during flowering period, ABA in leaves and roots vary more than in branches and culms, up to 109 % and 148 %, respectively. The most changes in flowering bamboo is the leaves turn to yellow and dry, some even depart, the roots stop growing and die out. But the branches vary less than the leaves and roots.5n IAA obviously reduces in leaves and in culms during flowering period. It shows that the leaves turn to yellow and dry to death, the culms turn to fade, yellow and dry out.6> The variation of GA3 is most remarkable. After flowering, the level of GA3 decreases, especially in roots, the extent is up to 83 %. In flowering bamboo it shows that the roots stop growing and then turn to die.