The Development of the Egg and Fertilization in Pinus Strobus

Abstract

With Plates XXIU, XXIV, and XXV. D URING the course of the present studies, the development of the archegonium and fertilization, together with the phenomena immediately preceding and following fecundation, were first carefully worked out in Pinus Strobus. Later, a far less extended study was made of Pinus austriaca, P. rigida, P. resinosa, and P. montana, var. uncinata. A complete series of stages in the development of these species was not obtained, and, therefore, the conclusions as set forth in this paper refer, unless otherwise stated, to Pinus Strobus, the other species being used only by way of .comparison. The methods employed in the preparation of the material for this research were fully described in my earlier paper ('01) and need not be repeated here. These investigations were begun, at the suggestion of Pro?. George F. Atkinson,.in the fall of 1897, and the principal results of the work, as herein described, were read before the Botanical Society of America at its Boston meeting in 1898. At this time Blackman's ('98) excellent article, ' Fertilization and Related Phenomena in Pinus sylvestris,' had

Behavior of Meiotic Chromosomes in Pinus wallichiana, P. strobus and Their Hybrid and nrDNA Localization in Pollen Mother Cells of the Hybrid by Using FISH

“…Pinus wallichiana Jacks (Himalayan white pine) is distributed from Southwestern China to South Asia (Fu et al 1999), while P. strobus L. (Eastern white pine) spreads widely in Northeastern America. The karyotypic formulae of both P. wallichiana (Mehra and Khoshoo 1956; Santamour 1960; Saylor 1983; Ohri and Khoshoo 1986; Mehra 1988) and P. strobus (Ferguson 1901, 1904; Sax and Sax 1933; Santamour 1960; Saylor 1961; Baranec 1979; Love and Love 1980; Saylor 1983) are K(2n) = 24 = 22m + 2sm, in which the shortest pair of chromosomes is of submedian centromere. The artifical hybrid (F 1 ) investigated in our study was created in 1970s by Zhou and Dong.…”

Crossability of Pinus sibirica and P. pumila with their hybrids

“…During the first year of cone development, pollination takes place, with pollen subsequently germinating and pollen tubes growing into the nucellus. The following year, the female gametophyte begins growing intensively; the megaspore, archegonia, and ovules are formed, and fertilization and embryo development then occur (FERGUSON, 1901;NEKRASOVA, 1972;OWENS and MOLDER, 1977). In five-needle pines, incompatibility manifests itself during the second year of cone development, and is usually evidenced by fertilization failure or rapid deteri-oration of the newly formed embryo (HAGMAN and MIKKOLA, 1963;KRIEBEL, 1972;FERNANDO et al, 2005).…”

On the Effect of a Centrifugal Force upon the Egg Cell and Proembryo of <i>Pinus Thunbergii</i> PARL. With Some Observations on Various Effects of Fixing Agents in the <i>Pinus</i> Egg Cell

“…Since STRASBURGER (1884) described the nucleus of the egg cell in the Abietineae as filled with a granular substance which he called " metaplasm ," many students have discussed the morphological feature of the egg-nucleus in pines, e.g. BLACKMANN (1898) in Pinus silvestris, CHAMBERLAIN (1899) in Pinus Laricio, FERGUSON (1901) in Pinus Strobus. There seems, however, to be a definite relation between the fixing agents and the structure of the nuclear cavity, the various appearances presented by the egg-nucleus depending largely upon the artifact due to fixing agents.…”