Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: 10/12/2000
Publication Date: N/A
Citation: Interpretive Summary: The dry seeds of common bean (P. vulgaris L.) are generally soaked and must be cooked before they are eaten. Beans are often cooked in commercial factories as whole grains in tin cans, or consumers may buy the mature dry beans in bulk or packages at the market, soak them overnight, and cook the seeds in an open kettle, on a stove top, or in a microwave oven. The conditions used to prepare beans for eating cause structural changes in cells that have a bearing on consumer and processor preferences and requirements for the soaked and cooked seeds. A prior knowledge of consumer and processor acceptability criteria for beans at dry, soaked, and cooked stages of processing led to the adoption of several tests that could assess bean culinary quality. Sixteen traits are routinely measured by the tests on beans. Genetic variability was confirmed for most of the traits because of the presence of significant mean squares from analyses of variance. Moreover, mating designs used to study the nature of the variability indicated that the traits are quantitative in nature (variation is continuous, i.e., differences are due to matters of degree), and the gene action is predominantly additive (genes show a linear increase on trait expression). The significant variation found for the evaluated traits indicated that they can be changed by selection. Today, many agencies routinely screen dry bean breeding lines for culinary quality. The improvement of food quality through plant breeding provides a low cost and environmentally sound means to enhance the nutrient content and consumer acceptance of this already nutritious global crop. An increase in the nutrients of new dry bean cultivars benefits the health and well being of consumers.
Technical Abstract: Culinary quality in dry bean (Phaseolus vulgaris L.) refers to the physical and chemical properties of dry and cooked seeds that influence consumer preference and processor standards. Beans not meeting culinary quality expectations may be unacceptable to processors and rejected by consumers. Tests were developed that differentiated culinary quality among samples in numerous experiments. The differences among samples were heritable and fro the use of mating designs, we determined that the variation was quantitative in nature. Both additive and nonadditive (dominance) variances contributed significantly to trait expression; however, additive variance predominated. Significant additive variances for color, soaking, and thermal characteristics in dry bean indicated that culinary quality traits can be altered by selection. Quantitative traits displaying predominantly additive variance in a population are best improved through recurrent selection. Evaluating a large number of processed bean samples is costly, time consuming, and may lack precision to detect small differences in quality. Recently, indirect selection using linked markers marker assisted selection has received attention as a method for increasing selection efficiency within breeding programs. One of the formidable roadblocks to success in the genetic improvement of quality are genotype x environmental interactions. Recently, interest has been focused on the stability or a lack of responsiveness to environmental variation of individual cultivars. There is compelling evidence from data in beans that stability for quality traits is under genetic control. Hence, the selection of cultivars with a high and stable mean performance is the best way for the breeder to counter genotype x environmental interactions.