Estimation for the timing of the internal developmental processes of acorns from fruit size in Quercus serrata Thunb. ex Murray

Abstract

To evaluate the relative importance of the factors affecting the premature abortion of acorns in Quercus serrata Thunb. ex Murray during the course of their development, inner developmental processes of acorns were observed by microscope, and applicability of the diameter of fruits (acorns with cupules) as an indicator of the inner developmental processes was discussed. Based on the observations using microscope, the developmental processes of acorns were classified into five stages; one prezygotic and four postzygotic stages (stages I to V). The diameter of sound fruits increased exponentially until 14 weeks after pollination, and the variance of diameter in each tree was fairly small (CV ϭ ~6%) during the process. Diameter of fruits can be used as a good indicator of developmental stages of acorns at individual level, and effective for the evaluation of the ecological factors affecting the premature abortion of acorns.

Timing of premature acorn abortion in Quercus serrata Thunb. is related to mating pattern, fruit size, and internal fruit development

“…The results described in the present study corresponded with previous measurements of acorn survival, fruit size growth, and internal fruit development, respectively (Kanazashi et al 1997;Kanazashi and Kanazashi 2003; see also the ''Introduction''). We also described the development and timing of abortion of acorns in the three pollination treatments.…”

“…Based on observations of internal fruit development, Kanazashi and Kanazashi (2003) divided the development of sound acorns into five stages: stage I, from pollination to fertilization; stage II, endosperm development; stage III, from the start of cotyledon differentiation to the time when only one embryo survives to develop in the ovary; stage IV, to the period of morphological completion of the embryo; and stage V, the further development of cotyledons. Our results showed that the timing of premature acorn abortion was strongly related to acorn growth and their staging (summarized in Fig.…”

“…To the best of our knowledge, only a few studies have described seasonal acorn drops in different mating types with artificial pollination (Hashizume et al 1994;Kanazashi et al 1997). The time course of the size growth of acorns (Hashizume and Ozaki 1979;Matsuda 1982;Kanazashi and Kanazashi 2003), embryo size development (Hashizume and Ozaki 1979;Matsuda 1982), and microscopic observations of internal fruit development (Kanazashi and Kanazashi 2003) have been reported in detail. However, no report has described the future development of unsuitably pollinated acorns, and no research has simultaneously compared the timing of premature acorn abortion to the time course of acorn development in different mating patterns in Quercus.…”

Physiological and morphological characteristics during development of pedunculate oak (Quercus robur L.) zygotic embryos

“…In view of their morphological development, and following the description provided by Kanazashi and Kanazashi (2003), the ZEs were assigned to one of the four stages.…”

“…(Mogensen 1965;Borgardt and Nixon 2003;Kanazashi and Kanazashi 2003). However, little information exists about the relationship between morphological characteristics and internal biochemical events.…”