Abstract. For the foreseeable future, plant breeding methodology will continue to unfold as a practical application of the scaling of quantitative biology. These efforts to increase the effective scale of breeding programs will focus on the immediate and long-term needs of society. The foundations of the quantitative dimension will be integration of quantitative genetics, statistics, gene-to-phenotype knowledge of traits embedded within crop growth and development models. The integration will be enabled by advances in quantitative genetics methodology and computer simulation. The foundations of the biology dimension will be integrated experimental and functional gene-to-phenotype modelling approaches that advance our understanding of functional germplasm diversity, and gene-to-phenotype trait relationships for the native and transgenic variation utilised in agricultural crops. The trait genetic knowledge created will span scales of biology, extending from molecular genetics to multi-trait phenotypes embedded within evolving genotype-environment systems. The outcomes sought and successes achieved by plant breeding will be measured in terms of sustainable improvements in agricultural production of food, feed, fibre, biofuels and other desirable plant products that meet the needs of society. In this review, examples will be drawn primarily from our experience gained through commercial maize breeding. Implications for other crops, in both the private and public sectors, will be discussed.

In xeric environments, water-use efficiency (WUE) is likely to be a target of natural selection. Higher WUE is expected to confer a fitness advantage in drought conditions, but this prediction has rarely been tested. To examine the relationships between WUE and fitness, two common garden experiments were conducted. Inbred lines of Impatiens capensis derived from wet and relatively dry sites were planted into dry field conditions in an open and a woodland site. The lines from the dry population increased their instantaneous WUE in response to the dry conditions of the field to a greater degree than lines from the wet population. High instantaneous WUE also conferred a fitness advantage in the stressful conditions of the field. Thus, WUE may be an important trait for I. capensis populations in adapting to drier conditions.

Water limitation is one of the most important factors limiting crop productivity world-wide and has likely been an important selective regime influencing the evolution of plant physiology. Understanding the genetic and physiological basis of drought adaptation is therefore important for improving crops as well as for understanding the evolution of wild species. Here, results are presented from quantitative trait loci (QTL) mapping of flowering time (a drought escape mechanism) and carbon stable isotope ratio (d d d

Five intense (category 3 or greater) hurricanes occurring in 1635, 1638, 1815, 1869, and 1938 have made landfall on the New England coast since European settlement. Historical records indicate that four of these hurricanes (1635, 1638, 1815, and 1938) and hurricane Carol, a strong category 2 storm in 1954, produced significant storm surges (Ͼ3 m) in southern Rhode Island. Storm surges of this magnitude can overtop barrier islands, removing sediments from the beach and nearshore environment and depositing overwash fans across back-barrier marshes, lakes, and lagoons. In a regime of rising sea level, accumulation of marsh, lake, or lagoon sediments on top of overwash deposits will preserve a record of overwash deposition. We examined the record of overwash deposition at Succotash salt marsh in East Matunuck, Rhode Island, and tested the correlation with historical records of intense storms. Aerial photographs taken after hurricanes in 1954 and 1938 show overwash fans deposited at the site. Analysis of 14 sediment cores from the back-barrier marsh confirmed the presence of these fans