Developmental Stages of Akebia trifoliata Fruit Based on Volume
Hao Yang, Wei Chen, Fu Peng, Shengfu Zhong, Ju Guan, Peigao Luo
Abstract
Akebia trifoliata, commonly named augmelon (means August plus melon), has been domesticating as a new artificial cultivation fruit crop in China for several years. Generally, field management measurements are severely dependent on the development dynamic of harvest organs, and therefore the study of fruit development stage of A. trifoliata is urgent in production. In this study, four cloned lines with various spindle, nephroid, pyriform and Banana-like shapes, were selected to observe fruit developmental parameters, including volume, weight, length and width from pollination to maturity. Volume rather than length or width, which can minimize the influence of fruit shape on growth stage, was finally employed as a primary parameter for dividing developmental stages. Then a Logistic model of volume growth was established according to the data of pyriform fruit, and the other three fruits were employed to the suitability of this mathematical model. The resulted showed that the growth curve of augmelon appeared typical double sigmoid shape for all four shapes fruits. Based on four inflection points of volume growth curve, the fruit development of augmelon was classified five developmental stages in the order: fast stretch (FS) stage lasting for 48 days, shape stabilization (SS) stage lasting for 30 days, tardy expansion (TE) stage lasting for 51 days, suspended expansion (SE) stage lasting for 21 days and fast expansion (FE) stage lasting for 30 days. Comprehensively, volume was an ideal growth parameter for dividing fruit developmental stage of augmelon, and five-stage growth model could be applied as reference for both gardener and scientist to refer to the fruit growth status.