Chun-Yan Yang

Evaluation of productivity and stability of elite summer soybean cultivars in multi-environment trials

Abstract Spring soybean cultivars produced in moderate climates currently represent almost the entire soybean industry; however, soybean production has the potential to be extended into the summer months in different regions of the world. It is critical to select the correct soybean cultivar for production in a specific environment. The purpose of this study was therefore to evaluate the productivity (yield) and stability of the current summer soybean cultivars in multi-environment trials in the Huang–Huai–Hai region, presently the largest summer soybean-producing region in the world, to determine which cultivars will be most successful for large scale production in this region, as well as those that should be used in future breeding efforts. A total of 94 summer soybean cultivars were grown in the three major soybean production provinces, i.e., Shandong, Henan, and Hebei, over 3 years (2008–2010). The GGEbiplot™ software provided a ‘genotype x genotype-by-environment interaction’ function to evaluate the importance of agronomic factors controlling the soybean yield of each cultivar across the nine different environments. Xudou10, Zhonghuang39, Lu93748-1 and Lu99-1 exhibited relatively high average yields. The stability among the high-yielding cultivars was ranked in decreasing order as Xudou10, Zheng99048, Jidou7, Yudou18, and Gaozuoxuan-1. Among all recorded factors, the pod number per plant was the most important factor controlling yield, followed by seed number per plant, effective branch number, and 100-seed weight, which positively affected soybean yield. In contrast, a higher bottom pod height, greater number of nodes on the main stem, and longer growth duration were negatively correlated with yield.

Analysis of Adaptability of Soybean Mini Core Collection in Huang-Huai Rivers Region in China

For evaluating the environmental adaptability and stability of soybean [Glycine spp.] germplasm, the data of important agronomic traits in a mini core collection were analyzed using the additive main effects and multiplicative interaction (AMMI) model. The mini core collection contained 60 accessions of soybean germplasm, and their agronomic traits were investigated in 6 trail sites in Hebei, Henan, and Shandong provinces of China from 2008 to 2009. The interactions between genotypes and environment (G × E) were significant (P < 0.01) in plant height, effective branch number, 100-seed weight, and yield per unit area, which accounted for 16.7–24.6% of total variations. Thus, it is necessary to dissect the environmental stability of the mini core collection. Adaptabilities of genotypes varied across planting sites in different traits. Some genotypes showed wide adaptability and good stability with small phenotypic variations in different sites; whereas, strong G × E interaction was observed in some other genotypes. This result provides a theoretical basis for effectively using the mini core collection in soybean breeding in the Huang-Huai Rivers Region of China.

Stability of growth periods traits for soybean cultivars across multiple locations

Abstract The growth periods (GPs, from planting/emergence to reproductive stage 8 (R8) of soybean cultivars vary in different ecological regions, especially in China with a very complex soybean cropping system. In this study, a 3-yr experimental study was undertaken in three geographical locations of China from 2008 to 2010, including the Northeast (40.66–45.85°N), Huang-Huai (34.75–38.04°N) and southern (22.82–30.60°N) eco-regions with about 250 accessions in each region to clarify the classification of maturity group (MG) and identify the cultivars with stable GP to increase the knowledge about the GP distribution of soybean cultivars in China. GPs of soybean cultivars in different eco-regions were significant different with a gradual decrease from 115–125 d in the Northeast part to the 85–100 d in the southern part of China. The geographical location was the major factor for GP of cultivars from the Northeast, while the year of planting was the major factor affecting the stability of GPs in Huang-Huai summer and southern summer soybean. AMMI2 (additive main effects and multiplicative interaction)-Biplot analysis showed that the GPs of soybean cultivars from the Northeast eco-region have a comparatively satisfactory environmental stability. Moreover, soybean cultivars with moderate GP/MG and stable environment adaptability in different eco-regions were identified based on the linear regression and AMMI analysis, which was important for the accurate classification of soybean MGs in future. Taken together, our results reflected the genetic diversity, geographical distribution and environmental stability of the Chinese soybean GP trait. Soybean cultivars with stable GP for various Chinese eco-regions would be beneficial for Chinese soybean genetic improvement, varietal introduction, exchange, and soybean breeding program for wide adaptability.