Nitrogen‐, water‐ and radiation‐use efficiencies affected by sugarcane breeding in Argentina

This study aimed to identify whether and how sugarcane (Saccharum spp.) breeding in Argentina modified nitrogen‐use efficiency (NUE), water‐use efficiency (WUE) and radiation‐use efficiency (RUE). Thirteen varieties were grown in two consecutive seasons. Trends in different traits were estimated by fitting the data to linear or bilinear regression models. There was a linear increase in NUE and WUE with the year of release throughout the 70‐year span, whereas water use was not modified by sugarcane breeding. There was a positive and strong (r > 0.90; P < 0.01) association between NUE and WUE and between sugar yield and NUE or WUE. Although RUE was not modified by sugarcane breeding, the amount of radiation intercepted by the crop increased with the year of release. Modern varieties had a higher maximum interception and needed fewer days to reach maximum interception than old varieties. This study suggests that applying ecophysiological knowledge would be instrumental in sugarcane breeding programmes in order to develop varieties with high resource‐use efficiency and capable to adapt to global climate change.     

Deployment of cold tolerance loci from Oryza sativa ssp. Japonica cv. ‘Nipponbare’ in a high‐yielding Indica rice cultivar ‘93‐11’

Cold tolerance is a complex trait, and QTL pyramiding is required for rice breeding. In this study, a total of seven QTLs for cold tolerance in the Japonica rice variety ‘Nipponbare’ were identified in an F_2:3 population. A stably inherited major QTL, called qCTS11, was detected in the region adjacent to the centromere of chromosome 11. In a near‐isogenic line population, the QTL was further dissected into two linked loci, qCTS11.1 and qCTS11.2. Both of the homozygous alleles of qCTS11.1 and qCTS11.2 from ‘Nipponbare’ showed major positive effects on cold tolerance. Through pyramiding the linked QTLs in the cold‐sensitive Indica rice cultivar ‘93‐11’, we have developed a new elite, high‐yielding Indica variety with cold tolerance.     

Renewing Canada's Manufacturing Economy: A Regional Comparison, 1973‐1996

ABSTRACT Regional economies are continually undergoing adjustment as their firm populations react to changing tastes, technologies, and the challenges of outside competition. Adjustment typically takes place as the stock of jobs is renewed in each industry. This micro‐dynamic process of renewal has a substantial impact on the structure of national and regional economies. The primary objective of this paper is to measure the degree of renewal within the Canadian manufacturing economy as whole and within individual provinces. Using a longitudinal micro‐data set—which covers the population of manufacturing plants in Canada from 1973 to 1996—the study shows that the manufacturing sector experienced considerable job renewal. Two‐thirds of jobs in 1996 were newly created since 1973. There was considerable variation in provincial renewal rates. A decomposition analysis suggests this variation is not purely an artifact of the types of industries found in provinces, but reflects other characteristics of provincial economies.     

Income Migration and Income Convergence across U.S. States, 1995–2010

In this paper we examine how internal migration redistributes earned income across U.S. states between 1995 and 2010. We examine interregional income flows by first describing the movement of earned income between U.S. states. Second, we examine the effect of income migration on spatial patterns of income inequality. The question we ask is, “does migration increase or decrease convergence income across U.S. States?” A primary contribution of this paper is that instead of using only 1 year of income migration data to explore these issues, we use yearly data from the first year the Internal Revenue Service (IRS) data started including income (1995/1996) up to the most current data available (2009/2010). Results indicate that income convergence/divergence across states varies by whether or not there is general economic expansion or contraction. Nevertheless, some high‐amenity states continually attract high‐income households.