%0 Journal Article
%T Adaptation to High Temperature and Water Deficit in the Common Bean (Phaseolus vulgaris L.) during the Reproductive Period
%A Hide Omae
%A Ashok Kumar
%A Mariko Shono
%J Journal of Botany
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/803413
%X This paper reviews the adaption to heat and drought stresses in Phaseolus vulgaris, a grain and vegetable crop widely grown in both the Old and New World. Substantial genotypic differences are found in morphophysiological characteristics such as phenology, partitioning, plant-water relations, photosynthetic parameters, and shoot growth, which are related to reproductive responses. The associations between (a) days to podding and leaf water content and (b) the number of pods per plant and seed yield are consistent across different environments and experiments. Leaf water content is maintained by reductions in leaf water potential and shoot extension in response to heat and drought stress. Heat-tolerant cultivars have higher biomass allocation to pods and higher pod set in branches. These traits can be used as a marker to screen germplasm for heat and drought tolerance. In this paper, we briefly review the results of our studies carried out on heat and drought tolerance in the common bean at the Tropical Agriculture Research Front, Ishigaki, Japan. 1. Introduction Transitory or constantly high temperatures cause an array of morphoanatomical, physiological, and biochemical changes in plants, which affect plant growth and development and may lead to a drastic reduction in economic yield. The adverse effects of heat stress can be mitigated by developing crop plants with improved thermotolerance using various genetic approaches [1]. However, achieving this requires a thorough understanding of the physiological responses of plants to high temperature, the mechanisms of heat tolerance, and potential strategies for improving crop thermotolerance. The common bean (Phaseoluls vulgaris L.) is originally a crop of the New World [2], but it is now grown extensively in all major continental areas [3]. Its production spans from 52¡ãN to 32¡ãS latitude [4] and from near sea level in the continental US and Europe to elevations of more than 3000£¿m in Andean South America. The common bean has two major gene pools [5], the Andean and the Mesoamerican, based on their centers of origin in South and Central America, respectively [6]. Within these gene pools are a total of six races, including three Mesoamerican (Mesoamerica, Durango, and Jalisco) and three Andean (Peru, Nueva Granada, and Chile) [7, 8]. An additional Mesoamerican race has been designated Guatemala, which includes certain climbing beans from Central America [9]. After domestication, the common bean spread across Mesoamerica and South America and, after the European discovery of the Americas, to Europe and Africa,
%U http://www.hindawi.com/journals/jb/2012/803413/