Breeding progress for grain yield and associated traits in medium and late maturing promiscuous soybeans in Nigeria

Abstract

The rate of breeding progress of 10 medium and 11 late maturing promiscuous soybean varieties developed by IITA for the savanna zones of Nigeria from 1980 to 1996 was assessed at two locations in 2001 and 2002. The two maturity groups were evaluated in separate experiments using randomized complete block design with four replications. There were highly significant effects of variety on grain yield, fodder yield, and another set of eight traits both in the medium and late maturity groups. In the medium varieties, grain yield increased linearly from 1184 kg ha -1 for an old variety TGx 1019-2EN to 1764 kg ha -1 for TGx 1910-7F released in 1996. The annual rate of progress against year of release was 23.61 kg ha -1 (1.99%). Modern varieties of the medium maturity group had high number of pods per plant, high harvest index, and reduced pod shattering. For late varieties, grain yield ranged from 1569 kg ha -1 for an old variety Samsoy-2 to 2303 kg ha -1 for a recently developed variety TGx 1910-14F. The annual rate of breeding progress during the improvement period of 16 years for late varieties was 22.23 kg ha -1 or 1.42%. The overall yield of the late maturing varieties was 19% higher than the medium maturing varieties.

Breeding for Promiscuous Soybeans at IITA

“…Similarly in medium maturing varieties of soybean the annual rate of progress against year of release was found to be 23.6 kg ha -1 or 1.99% (Tefera et al, 2010). For late maturing varieties, the annual rate of breeding progress during 16 years of improvement period was 22.2 kg ha -1 or 1.42% (Tefera et al, 2010).…”

Agronomic Response of Soybean Varieties to Plant Population in the Guinea Savannas of Nigeria

“…It contributes to improving soil fertility and reducing Striga infestation on farmers’ fields (Sanginga et al, 2002; Franke et al, 2004). The International Institute of Tropical Agriculture's (IITA) soybean improvement work in Africa started in the mid‐1970s, mainly to increase productivity, which was 0.5 Mg ha −1 (Tefera et al, 2010). Other major constraints to soybean production that necessitated IITA's intervention were low seed viability from harvest to the next planting season, poor nodulation of soybean cultivars with the indigenous Rhizobium spp., pod shattering, and foliar diseases such as frogeye caused by Cercospora sojina and bacterial pustule caused by Xanthomonas axonopodis pv.…”

Breeding Progress, Adaptation, and Stability for Grain Yield in Moroccan Lentil Improved Varieties

“…One of the methods widely used to estimate the progress made from genetic gain achieved in plant breeding programs is the regression of the average performance of released varieties for a specific trait in different environments over their years of release (Duvick, 1984). ; Tefera et al, 2010]. ; Tefera et al, 2010].…”

“…This estimation has been used for several major crops, for instance in wheat (Triticum aestivum L.; Peltonen-Sainio and Peltonen, 1994;De Vita et al, 2007;Giunta et al, 2007;Mladenov et al, 2011, Taghouti et al, 2017Laidig et al, 2017b), barley (Hordeum vulgare L.; Laidig et al, 2017a), chickpea (Cicer arietinum L.; Tadesse et al, 2018), common bean (Phaseolus vulgaris L.; Barili and do Vale, 2016), and soybean [Glycine max (L.) Merr. ; Tefera et al, 2010].…”