Physiological characteristics of pistil abortion in Prunus sibirica

Pistil abortion in Prunus sibirica was associated with insufficient supply of nutrient, auxins, and gibberellins in flower buds, which promotes pistil development, and accumulation of cytokinins, which inhibits pistil development. Prunus sibirica is an important ecological and economic tree species with high utilization potential and broad application prospects. However, pistil abortion affects its fruit setting, yield, and quality, restricting its industrial development. In this study, the type and stage of pistil abortion in P. sibirica were identified using flower buds with abortive and fertile pistil. The effects of different nutrients and endogenous hormones on pistil abortion were analyzed. The pistil abortion type of P. sibirica clone belonged to abnormal style structure, and the key stage of pistil abortion was the dew white stage, characterized by pistil degeneration and dissolution at the dew white stage and complete pistil disintegration and disappearance at the full blooming stage. The soluble protein, soluble sugar, and total sugar contents of flower buds with abortive pistils were significantly lower than those of flower buds with fertile pistils at the dew white, initial blooming, and full blooming stages. Among the 44 hormones detected in flower buds of P. sibirica, majority were cytokinins (CKs 25), followed by auxins (13). At the dew white stage, the CK content in flower buds with abortive pistils was significantly higher than that in flower buds with fertile pistils. Pistil abortion in P. sibirica was mainly due to insufficient supply of soluble protein, soluble sugar, and total sugar in flower buds; insufficient supply of auxins and gibberellins, which promotes pistil development; and accumulation of cytokinins, which inhibits pistil development.