Study on Carbohydrates Contents in the Terminal Shoots during Bud Dormancy of Three Peach (Prunus persica (L.)Batsch) Cultivars

Abstract

Irregular flowering in many peach cultivars is caused by insufficient cold period needed for breaking the dormancy of flower buds. This phenomenon is probably results from insufficient reserved food content in the shoot. The study on reserved carbohydrates contents in the terminal shoot during the dormant stage of three peach cultivars grown at the Royal Ang Khang Station, Amphur Fang, Chingmai Province was conducted. Three peach cultivars of varied chilling requirements namely Flordabelle, Ang Khang White and Ventura were studied by sampling the terminal shoots fortnightly from the beginning of bud dormancy until bud break. The terminal shoot of 5 cm long that bear these excised buds was analysed for reducing sugars (RS) and total non-structural carbohydrates (TNC) contents. The results show that the TNC content in the shoots was high at the first period after the onset of dormancy and sharply decreased thereafter. Similar pattern of changing in that dormant period was seen in the reducing sugar contents. Thereafter the reducing sugar and TNC contents were gradually increased until flowering. However, no relationship was found between the average contents of reducing sugars and TNC in the terminal shoot and the dormancy period of flower buds in these three peach cultivars.