Reproductive bud development of pears (Pyrus communis L.) with emphasis on the bourse shoot
Date
2005-04
Authors
Reynolds, L. P.
Jacobs, G.
Theron, K. I.
Journal Title
Journal ISSN
Volume Title
Publisher
International Society for Horticultural Science -- ISHS
Abstract
For consistent yields in pear fruit production, knowledge of the development
of the reproductive bud is required. The aim of this study was to gain more insight
into the development of the primordial bourse shoot. The bourse shoot is important
because of the ability of a bourse shoot to become reproductive, which can lead to
bourse-over-bourse bearing. The progression of reproductive bud development in
‘Forelle’ and ‘Rosemarie’ was studied from primordial bourse shoot initiation until
dormancy the following season. The primordial bourse shoot development in the
reproductive bud before full bloom is poorly documented. The primordial bourse
shoot was initiated in February 2003. The primordial bourse shoot development
progressed during dormancy with a plastochron length of 60 to 80 days in June. The
rate of preformed leaf formation increased rapidly until August, when the
plastochron was 5 days. ‘Rosemarie’s’ primordial bourse shoot development was
more advanced at full bloom. This is one of the possible reasons for the higher
bourse-over-bourse bearing habit of the cultivar. The number of leaves of the bourse
shoot of ‘Rosemarie’ was significantly greater than with ‘Forelle’, which has a low
tendency for bourse-over-bourse bearing. Flower initiation of the terminal bud of
the bourse shoot was 56 and 77 days after full bloom for ‘Forelle’ and ‘Rosemarie’,
respectively. Initiation was well correlated with the cessation of bourse shoot growth.
An increase in mitotic activity occurred during flower differentiation of the terminal
bourse bud, with a peak of floral appendage formation during December and
January. From February until dormancy enlargement of the floral parts took place.
Description
The original publication is available at http://www.actahort.org/books/671/671_20.htm
Keywords
Pears -- Reproductive bud development, Pears -- Flower initiation, Pear fruit production
Citation
Reynolds, L. P., Jacobs, G. & Theron, K. I. 2005. Reproductive bud development of pears (Pyrus communis L.) with emphasis on the bourse shoot. Acta Hort. (ISHS) 671:165-170.