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The Genetic Basis Of Adaptation To Environmental Stress In Two Grass Genomic Model Systems, David Mitchell Goad

Arts & Sciences Electronic Theses and Dissertations

Plants are exposed to a wide variety of environmental stress in the wild and have developed an equally diverse set of adaptations to tolerate them. The evolutionary processes that have led to this functional diversification, and the specific genes and physiological mechanisms involved, are of immense interest to both evolutionary biologists and crop breeders. In this dissertation I investigate adaptation to different types of environmental stress in two economically important grass species, seashore paspalum (Paspalum vaginatum Sw.) and rice (Oryza sativa L.).

Seashore paspalum is a halophytic turfgrass that occupies habitats which can dramatically differ in salt concentration. Populations may …

Leaf Number Indicates Salt Tolerance Of Young Seedling Families Of European Aspen (Populus Tremula L.) Growing In Different Soils, Lu-Min Vaario, Kim Yrjälä, Matti Rousi, Timo Sipila, Pertti Pulkkinen

Aspen Bibliography

Soil salinity limits plant productivity and quality. We evaluated the response of 12 aspen (Populus tremula) families to salt stress in two different soils irrigated for 4-weeks with 0, 80 or 160 mM saline solution. Easily measurable characteristics such as shoot height, leaf number, dry mass as well as the distribution of sodium (Na+) ions were measured in 5-month-old aspen seedlings raised in controlled greenhouse conditions on two different soils. Growth among families varied significantly, and the interaction between family and soil type was significant. From 2–5 months, leaf number correlated with that of the first month and salin-ity tolerance. …