Chilling privation during dormancy period and carbohydrate mobilization in Japanese pear trees

Scientia Agricola

Anderson Carlos Marafon²  Idemir Citadin¹  Luciano Do Amarante¹  Flávio Gilberto Herter¹  Fernando José Hawerroth¹ 

[1] ,Embrapa Tabuleiros Costeiros Unidade de Execução de Pesquisa de Rio Largo Rio Largo AL ,Brasil

关键词: Pyrus pyrifolia;    carbohydrates;    floral bud abortion;    cell wall acid invertase;    sucrose-phosphate synthase;   

DOI  :  10.1590/S0103-90162011000400011

来源: SciELO

【 摘 要 】

The flower bud abortion is one of the main problems that limit commercial pear (Pyrus pyrifolia) production in the southern region of Brazil. Insufficient chilling during the dormancy period is known as the main factor of this problem. One of the hypotheses to explain this problem is that the starch mobilization and carbohydrate fluxes to the buds are impeded when mild temperatures occurred during winter. This study compared the total soluble sugars (TSS) and reducing sugars (RS) concentrations, the cell wall acid invertase (CWAI - EC 3.2.1.26) and sucrose-phosphate synthase (SPS - EC 2.4.1.14) activities in wood of branches and floral buds of Japanese pear trees cv. Housui, grafted on Pyrus calleryana and submitted to chilling conditions during the dormancy period. Treatments were: (i) natural conditions; (ii) continuous artificial chilling; (iii) alternating temperatures, and (iv) total chilling privation. TSS and RS contents, as well as CWAI and SPS activities in tissues of branches that received insufficient chilling were lower than those that received sufficient chilling during winter. The starch concentration was superior in wood tissues of branches kept under chilling privation. The chilling privation disturbs carbohydrate mobilization in pear trees, reducing the sucrose synthesis capacity in wood tissues (source) and sucrose importation by the floral buds (sink).

【 授权许可】

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