Genetic parameters of agronomic traits in soybean (Glycine max [L.] Merrill) genotypes tolerant to drought

Abstract

Soybean (Glycine max [L.] Merrill) planted in rainfed land during dry season often experiences crop failure due to drought. The objective of this study was to estimate the tolerant level and genetic advance values of 36 soybean genotypes on agronomic traits tested in drought and optimal irrigated conditions. The field research was conducted in Malang, East Java, Indonesia during late dry season of 2016. The soybean genotypes were tested in two environments, namely optimal condition (irrigation was applied until pods ripening) and drought condition (irrigation was applied until flowering). Results of the study showed that based on the genetic advance value, the number of branches per plant and the number of fertile pods per plant could be used as soybean selection criteria in normal irrigation and drought condition, respectively. In general, the mean of all traits in drought condition were lower than those in normal irrigation condition. Seed yield (t/ha) showed the lowest drought stress tolerant index (STI) (0.72). Based on the drought STI, four soybean lines (TGm-161-25-10, AB-142-40-21, AB-157-41-22, and ARG/GCP) had STI values of 1.0 and above 1.0 which are equivalent to the check drought tolerance variety Dering 1. These soybean lines could be grown in drought-stressed conditions.