Abstract:
Objective To understand and grasp flower bud anatomical characteristics and carbon and nitrogen nutrition of Litsea cubeba in female flower bud differentiation, and provide reference for artificial cultivation and cross breeding of Litsea cubeba.
Method The histological anatomy of the female flower bud differentiation of L. cubeba was observed by paraffin section method. The carbon and nitrogen nutrition indexes of soluble sugar, starch, soluble protein and carbon nitrogen ratio were determined by physiological kit and spectrophotometry.
Result (1) The differentiation of the female flower bud in L. cubeba followed five stages:undifferentiation, inflorescence primordium differentiation, bract primordium differentiation, flower primordium differentiation and floral organ differentiation. (2) The soluble sugar content of leaves increased with the development of the female flower bud differentiation, and the highest value was 65.07 mg·g-1. The starch content of leaves increased at first and then decreased with the development of the female flower bud differentiation, and the highest value appeared in the stage of bract primordium differentiation, which reached 81.30 mg·g-1, and the lowest value appeared in floral organ differentiation stage, which was 52.19 mg·g-1. (3) The content of soluble protein in leaves decreased continuously from 61.32 mg·g-1 to 52.48 mg·g-1 in the first three stages, and then remained stable. The ratio of carbon to nitrogen in leaves increased continuously from 1.49 to 2.61 in the first three stages, and then remained stable in the high level.
Conclusion The internal anatomical characteristics of the female flower bud differentiation of L. cubeba are similar to those of the male flower bud differentiation, and the female flower bud differentiation is divided into five periods. More and more soluble sugars are accumulated in leaves in the process of the female flower differentiation, and soluble proteins decreases obviously, while the ratio of carbon to nitrogen increases and remains at a relatively high level.