Studied on the Correlation between Tuber Growth and Endogenous Hormones in the Leaves and Polysaccharides Contents of Bletilla striata

PurposeIn order to explore the correlation between tuber growth and endogenous hormones in the leaves of Bletilla striata, and to provide a basis for the regulation of the growth and development in B. striata using hormones in production and research.

MethodsThe content of the tuber mass and polysaccharides and endogenous hormones in the leaves of B. striata in the seedling stage, vigorous growth stage, flowering stage, tuber enlargement stage, senescence stage and harvest stage were measured in three different ages from domesticated, annual and biennials. Endogenous hormones include IAA, GA₃, ZT, ABA. The hormone content was determined by ELISA enzyme-linked immunosorbent assay; the polysaccharide content was determined by phenol-concentrated sulfuric acid method.

ResultsThe tuber quality of the three different ages generally showed an upward trend, and all of them reached the maximum value at the harvesting stage. The polysaccharide content also showed an upward trend. Except for the two-year-old plants, the domesticated plants and the annual plants were all harvested. During the period of growth, the contents of the three hormones ZT, IAA and GA₃ showed a trend of rising first and then decreasing, while the content of ABA increased during the whole growth period. Correlation analysis showed that tuber yield and polysaccharide content showed a significant positive correlation from the flowering stage and reached a very significant correlation at the harvesting stage; endogenous ABA and tuber yield and polysaccharide content were negative at the seedling stage to the flowering stage. Correlatively, there was a positive correlation from the tuber enlargement period to the harvest period, and there was a significant correlation in the tuber enlargement period.

ConclusionIn order to promote root activity and ensure the absorption of various nutrients such as minerals in the soil at the seedling stage, ZT and IAA should be applied to the leaves on a regular basis; IAA should be applied in a timely manner during the vigorous growth stage, with an emphasis on external application. GA₃ enhanced the photosynthetic capacity of leaves and promoted the accumulation of photosynthetic products. The enlargement of tubers promoted the continuous enlargement of tubers and the accumulation of the products. Appropriate leaves were applied to ABA.