Evaluation of local soybean varieties for root and shoot growth and architecture

Abstract

This study was carried out to evaluate the root and shoot growth and architecture of local soybean varieties under normal and dehydration treatments in order to select the most drought resistant and the most drought sensitive candidates for further research. Seven soybean varieties including six soybean varieties from Mekong-delta region and the control genotype D51 were tested with three replications. The experiment was set up in two parts. For the first part, soybeans were evaluated at seedling and V3 stages under normal conditions. For the second part, soybeans were tested under drought conditions. MTD 765 was found to have longest tap root length, longest shoot length, highest root and shoot dry weight as well as drought index. In contrast, MTD 720 showed shortest tap root length and shoot length, lowest root and shoot dry weights as well as drought index. As the results, MTD 765 and MTD 720 are candidates for drought-resistant and drought-sensitive genotypes, respectively. This study is the important first step of our project for improvement of drought tolerance in local soybean varieties. These two candidates will be used later to screen the expression of stress-responsive genes in order to identify and isolate genes which are contribute to drought responses of the local soybean genotypes.

Key words: Soybeans, drought tolerance, tap root length, shoot length, drought index.