INHERITANCE OF PLANT HEIGHT, INTERNODE LENGTH AND BRANCH NUMBER IN CLIMBING COMMON BEAN POPULATIONS (PHASEOLUS VULGARIS L.)

摘要

Climbing common bean (Phaseolus vulgaris L.) genotypes have among the highest yield potential of all accessions found in the species and are distinct from bush bean varieties of common beans because they have tall growth, long internodes and twining ability. They are an important component of traditional agriculture in several parts of Latin America, especially Mexico, Guatemala, Colombia, Ecuador, and Peru and have spread to the Great Lakes region of Africa. Climbing beans are often grown in association with maize, either in relay or simultaneous plantings, and maize provides the support required for the climbing beans to grow upwards. In monoculture, climbing beans are planted with the support of wood or bamboo stakes or trellis systems. Trellising, a widespread system in the Andean region, is an alternative that reduces the need for stakes, but requires an investment in wires, string and labor for tying up bean vines. Trellising of climbing beans is economically justified because yields in monoculture may surpass 4500 kg ha-1. Therefore, climbing beans are particularly useful for small landholdings in situations where labor is not limiting and where demand for beans is high. Genetic improvement of climbing beans would benefit from an understanding of the inheritance of climbing capacity (made up of plant height and internode length traits). Therefore, the objective of this study was to determine the inheritance of climbing capacity traits in three crosses made within and between gene pools using generation means analysis.