Estimate of genetic consistency, diversity and traits association in late-maturing soybean breeding lines

Abstract

Soybean (Glycine max (L.) Merrill) a multipurpose food and fodder, is an important source of quality protein and oils. Despite this, its breeding-true ability which has implication for seed re-use, association between grain yield and other traits and its suitability for southern guinea savannah of Nigeria are not established. Hence, the objectives of the study are to determine the: i. genetic consistency of seed trait; ii. adaptability of late maturing variety of soybean and iii. establish the association between primary traits and yield. Data collected on growth and yield parameter in 16 genotypes were analyzed using SAS. Path analysis was used to show cause-effect relationship while dendogram depicted the association among line. The result revealed wide genetic diversity among the TGX genotypes and association between farmers seeds and commercial seeds. The lines were also true to type for grain yield and other characters. Hence, resource poor farmers can save good yielding seeds harvested, for planting in subsequent season. Breeders can use traits such as vigor, the number of branches and leaves at 10 weeks, plant height and the number of leaves at 6 weeks with direct positive and significant relation with economic yield to improve yield. Genotypes TGX 2008-2F, TGX 2007-11F and TGX 2009-16F are promising lines and better replacement to the local check. Therefore, further breeding efforts could be carried out to improve the lines for grain yield and fodder in order to achieve dual usage for the soybean lines and hence enhance food and nutritional security and improve livelihood of resource poor farmers in Nigeria.