Sodium nitroprusside and acetylsalicylic acid provided earliness in peach flower bud phenological stages by triggering xylogenesis

Temperate trees are subjected to a quiescent state during autumn and winter called dormancy. During buds growth, xylogenesis was observed between buds and shoots to maintain water and nutrients. In the present study, the effect of sodium nitroprusside (SNP) and acetylsalicylic acid (ASA) on peach ( Prunus persica (L.) Batsch, ‘J. H. Hale’) flower bud phenological stages and xylogenesis between buds and shoots was investigated. Shoots were collected during the leaf fall from peach trees grafted onto the Garnem rootstock ( P. dulcis × P. persica ), wrapped in a damp cloth, and stored at 4 ± 1°C temperature for 850 h. After the chilling treatment, the shoots were placed for a month in a controlled chamber with environmental conditions of 21°C temperature, 65% relative humidity, and 16/8 h photoperiod. Five days after the chilling treatment (DACT), the shoots were treated with SNP and ASA, except the control. During the experiment, SNP and ASA treatments provided earliness in the stages of flower bud development. Xylogenesis was observed in all treatments starting with 11 DACT. In this stage, xylem observation was found more clearly in using SNP and ASA compared to the control. The results of the experiment showed that using SNP and ASA provides earliness in flowering via increasing xylogenesis between buds and shoots.