US - Philippines Cooperative Research: Tolerance of SelectedMaize Genotypes to Nutritional Problems Related to Soil Acidity

该提案要求资金允许博士。克莱姆森大学农学和土壤系的Susan U. Wallace和Ulysses S. Jones与菲律宾大学Los Ba~os （UPLB）植物育种研究所的Henry P. Samonte博士一起进行为期24个月的项目研究，研究选定的玉米基因型对与土壤酸度有关的营养问题的耐受性。玉米基因型将从UPLB的田间筛选计划中选择，在那里它们将在菲律宾三种不同的酸性土壤上进行生长、产量和营养状况评估。将鉴定与植物适应有关的营养因子，并确定玉米基因型改变根区酸度的差异能力。据估计，世界上近一半的非灌溉耕地由酸性土壤组成。在强酸土壤中，植物的生长可能受到几种矿物胁迫中的一种或多种的限制，包括磷、钙、镁的缺乏，以及氢离子、锰和铝的过量。克服酸性土壤不孕症的一种方法是用石灰等抗酸剂和补充矿物质进行化学处理。另一种更适合较不富裕国家的方法是鉴定适应土壤酸度的植物基因型。在这个项目中，合作者将确定这些玉米基因型以及与适应一种或多种酸性土壤相关的植物性状。含有这些适应性性状的种质将被生理学家和遗传学家用于进一步的研究。美国和菲律宾的合作者是备受尊敬的科学家，他们过去曾成功合作过。该项目与“发展中国家科学项目”的目标相关，该项目旨在通过科学信息、思想、技能和技术的交流以及在互利问题上的合作，提高美国科学家和工程师与发展中国家同行之间的合作水平。

This proposal requests funds to permit Drs. Susan U. Wallace and Ulysses S. Jones, Department of Agronomy and Soils, Clemson University, to pursue with Dr. Henry P. Samonte, Institute of Plant Breeding, University of the Philippines at Los Ba~os (UPLB), for a period of 24 months, a program of research on the tolerance of selected maize genotypes to nutritional problems related to soil acidity. The maize genotypes will be selected from the field screening program at UPLB where they will be evaluated for growth, yield, and nutritional status on three diverse acid soils of the Philippines. Nutritional factors related to plant adaptation will be identified, and the differential ability of the maize genotypes to modify root zone acidity will be determined. It has been estimated that nearly one half of the world's nonirrigated arable land area consists of acid soils. In strongly acid soils, plant growth may be limited by one or more of several mineral stresses, including deficiencies of phosphorus, calcium, and magnesium, and excesses of hydrogen ions, manganese, and aluminum. One approach to overcoming acid soil infertility is chemical treatment with such antacids as lime and supplementation of minerals. Another approach, more suitable in the less affluent countries, is to identify plant genotypes which adapt to soil acidity. In this project, the collaborators will identify such maize genotypes as well as plant traits associated with adaptation to one or more of these acid soils. Germ plasm containing these adaptive traits will be used by physiologists and geneticists for further study. The U.S. and Philippine collaborators are highly respected scientists who have successfully collaborated in the past. This project is relevant to the objectives of the Science in Developing Countries Program which seeks to increase the level of cooperation between U.S. scientists and engineers and their counterparts in developing countries through the exchange of scientific information, ideas, skills, and techniques and through collaboration on problems of mutual benefit.