Karyotype Analysis of Pinus Silvestris

Abstract

WO circumstances made the present study of the chromosome mor-T phology of Pinus silvestris necessary. 1) Although many cytological investigations have concerned this and other Pinus spp. (SAX and SAX, 1933; MERCEN and NOVOTNY, 1957;AASS, 1957;HAKANSSON, 1956), there is no critical study of the karyotype of Pinus silvestris. 2) Since this species is increasingly used for radio-biological studies involving cytological observation (SUSZKA a.o., 1960), a clear understanding of its basic karyotype is essential. Whereas the lack of a satisfactory technique seems to have been the main difficulty in earlier studies, several combinations of pretreatments and fixations, applied in the present study, appeared to constitute a useful technique. As we have been able to obtain satisfactory results by our method, we hope that this description will be of value for investigators working with other gymnosperms as well. MATERIAL AND METHODSPrimary root nieristems of recently germinated seeds were used. The material was collected in Sweden from Bogesund (59'24') and Kiruna (67O51'). Since even the metaphase chromosomes of Pinus are generally very long, they are easily broken with ordinary chemical pretreatments or light physical pressure during the process of squashing. Extreme care must therefore be exercised in the choice of pretreatment and pressure to be applied during the preparation of the slide. The following technique, which is a modification of the one previously used (HHADURI

Chromosome banding in the genus <i>Pinus</i> V. Fluorescent banding patterns in 16 diploxylon pines

“…Natarajan et al 1961;Cesca and Peruzzi 2002) and C-bands (Borzan and Papeš 1978; MacPherson and Filion 1981) but they seem less reproducible and difficult to compare among studies or species. The difficulty of karyotype analysis in Pinus may be cause by their large genome size (Ohri and Khoshoo 1986;O'Brien et al 1996;Morse et al 2009) or long chromosomes.…”

Morphometric analysis on chromosomes of tropical <i>Pinus</i> species.

“…In several works using staining with Giemsa solution, secondary constrictions were not considered as reliable data for chromosome characterization (SAYLOR, 1961(SAYLOR, , 1964(SAYLOR, , 1972NATARAJAN et al, 1961;PEDERICK, 1967;DAVIDE and ARAÚJO, 1993). In this work, as well, the secondary constrictions were not revealed clearly when chromosomes were stained by Giemsa.…”

“…Secondary constriction is one of the markers that may aid in identifying single chromosomes in the genus Pinus (SAYLOR, 1961;PEDERICK, 1967;DAVIDE and ARAÚJO, 1993). Nevertheless, some works report that secondary constrictions are not reliable enough to be used to distinguish chromosomes of similar sizes (NATARAJAN et al, 1961;DAVIDE and ARAÚJO, 1993). Consistent identification of this cytological marker can provide important further information for the distinction of Pinus chromosomes.…”

Karyotype Analysis of Pinus Rigida

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URING the last years a series of publications relating to the karyo-D type analysis of conifer species have appeared (MEHRA and KHO-SHOO, 1956a, b;NATARAJAN et al, 1961;SAYLOR, 1961). The present paper deals with the results of a karyotype analysis of pitch pine (Pinus rigida MILL), one of the useful tree species in Korea.

Material and Methods

Seeds of Pinus rigidn MILL.

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