Genome size and environmental factors in the genus Pinus

• Published in: American journal of botany Vol. 80; no. 11; pp. 1235 - 1241
• Main Authors: Wakamiya, I, Newton, R.J, Johnston, J.S, Price, H.J
• Format: Journal Article
• Language: English
• Published: Ithaca, NY American Botanical Society 01-11-1993; Botanical Society of America; Botanical Society of America, Inc
• Subjects: ADN; AMERICA DEL NORTE; AMERIQUE DU NORD; ANALISIS CUANTITATIVO; ANALYSE QUANTITATIVE; Angiosperms; Animal and plant ecology; Animal, plant and microbial ecology; Autoecology; Biological and medical sciences; Botany; Cytometry; Deoxyribonucleic acid; DIMENSION; DNA; Ecology and Phytogeography; Embryos; Environmental factors; FACTEUR DU MILIEU; FACTORES AMBIENTALES; Fundamental and applied biological sciences. Psychology; Genetic variation; Genome size; GRAINE; Haploidy; INTERACCION GENOTIPO AMBIENTE; INTERACTION GENOTYPE ENVIRONNEMENT; Introduced species; Lasers; NOYAU CELLULAIRE; NUCLEO; PINUS; Plants; Plants and fungi; Seed weight; SEMILLA; TECHNIQUE ANALYTIQUE; TECNICAS ANALITICAS; VARIACION ESTACIONAL; VARIATION SAISONNIERE; VARIEDADES; VARIETE; North America; America; Climate; Seeds; Thermal factor; Growth; Environmental factor; Woody plant; Pinus; DNA; Morphology; Gymnospermae; Humidity; Coniferales; Spermatophyta; Habitat; Spectrophotometry; Adaptation
• ISSN: 0002-9122; 1537-2197
• DOI: 10.1002/j.1537-2197.1993.tb15360.x

Nuclear 1C DNA content in haploid megagametophyte tissue of 18 North American and one exotic Pinus species was determined using scanning microspectrophotometry. The nuclear DNA content in root meristematic cells of Zea mays L. ssp. mays, inbred line Va35 (4C = 10.31 pg) was used as a standard. DNA content measured by microspectrophotometry was verified using laser flow cytometry with two additional standards, Hordeum vulgare cv. Sultan (2C = 11.12 pg) and P. eldarica (2C = 47.30 pg). DNA values obtained by both methods were significantly correlated (r = 0.987). The 1C nuclear DNA content ranged from 21 pg to 31 pg. The ratio of DNA content in embryo tissue of P. eldarica to that in megagametophyte tissue was 1.72 by scanning microspectrophotometry and 1.74 by laser flow cytometry. To date, this is the most comprehensive data set available for North American Pinus species. Relationships between genome size of 18 North American Pinus species and climatic factors and indices of growth were investigated using regression and correlation analyses. Positive correlations were observed between nuclear DNA content and growth indices, minimum seed-bearing age, and seed dimensions. Strong negative correlations were observed between nuclear DNA content and two climatic factors, the lowest mean annual and monthly precipitation (excluding January) and the highest mean monthly spring air temperature. These correlations suggest that the large genome size and its variation in Pinus are adapted responses to the habitats of these species