R. Mcgarry et al., Differences in fruit development among large- and small-fruited cultivars of saskatoon (Amelanchier alnifolia), J AM S HORT, 126(4), 2001, pp. 381-385
Citations number
22
Categorie Soggetti
Plant Sciences
Journal title
JOURNAL OF THE AMERICAN SOCIETY FOR HORTICULTURAL SCIENCE
Fruit growth in saskatoons (Amelanchier alnifolia Nutt,), an emerging horti
cultural crop across the Canadian prairies, results from development of the
mesocarp and the endocarp-locular-ovular structure which includes the deve
loping seeds. Contribution of these tissues to fruit size was assessed usin
g transverse sections of ovaries sampled at six developmental stages among
large- and small-fruited cultivars, Mesocarp development was similar among
the larger-fruited cultivars (Thiessen, Northline, and Smoky); the number o
f cells increased rapidly through Stage I [162 to 293 growing degree days (
GDDs)] of fruit growth, and cell number increase was minimal during Stages
II (293 to 577 GDDs) and III (577 to 747 GDDs), In 'Regent' fruit (a small-
fruited cultivar), the maximal rate of cell division was delayed until Stag
e II and the mesocarp contained fewer cells than the larger-fruited cultiva
rs at harvest maturity, Mesocarp cell enlargement was similar among all of
the cultivars studied where cell expansion was maximal during Stage I and c
ontinued at a slower rate during Stages II and m. The area of the endocarp-
locular-ovular structure was greatest for 'Thiessen' and 'Northline', midra
nge for 'Smoky', and smallest for 'Regent'. Data suggest that a minimum num
ber of mesocarp cells early in fruit development is required to attain maxi
mal mesocarp size, and that differences in cultivar fruit size are a functi
on of both the mesocarp and the endocarp-locular-ovular structure.