Characterizing Changes from a Century of Genetic Improvement of Soybean Cultivars in Northeast China

Abstract

The first soybean [Glycine max (L.) Merr.] breeding program in China was established in the northeast in 1913. A trend analysis of widely grown cultivars across Chinese soybean breeding history may provide a better perspective on the genetic progress in soybean. The objective of the current study was to assess the genetic change of 15 phenological, yield, and agronomic traits on widely grown cultivars in northeast China. Sixty-four soybean cultivars representing a span of 84 yr of release were included. The field experiments were conducted at three sites in each region during 2009, 2010, and 2011, and the annual genetic changes were obtained by regression analysis. The results showed that the yield gain in widely grown cultivars of different regions ranged from 6 to 16 kg ha −1 yr −1 due to improvements in different yield components in the last nine decades. In addition, modern cultivars demonstrated more upright plant architecture, fewer branches, shorter height, higher lodging resistance, and earlier flowering than obsolete cultivars. However, changes were insignificant in the height of the bottom pod and the node number. The changing rates of yield and phenological traits across these decades were constant, while that of agronomic traits were discontinuous. Days to flowering, branch number, and lodging score were more responsive to environments in new cultivars than in old cultivars. In conclusion, these findings indicate a substantial improvement in the yield, agronomic, and phenological traits resulted from long-term genetic breeding. This study also provides insight into developing new strategies for soybean genetic improvement in China and worldwide. Corresponding authors (hantianfu@ caas.cn; wucunxiang@caas.cn). Abbreviations: 100-SW, 100-seed weight; BLUE, best linear unbiased estimator; BLUP, best linear unbiased predictor; BN, branch number; C, cultivar; CV, coefficient of variability; DTF, days to first flower; DTM, days to maturity; E, environment; HBP, height of the bottom pod; JL, Jilin-Liaoning region; LS, lodging score; MG, maturity group; MSH, midsouth Heilongjiang region; NH, north Heilongjiang region; NN, node number; PH, plant height; PPP, number of pods per plant; R/V, ratio of the reproductive period to the vegetative period; RP, reproductive period; SPP, seeds per plant; SPPOD, seeds per pod; YPP, yield per plant.

Shifts in Soybean Yield, Nutrient Uptake, and Nutrient Stoichiometry: A Historical Synthesis‐Analysis

“…Our database, primarily from small‐plot experiments, showed similar yield gain per year to the 25.8 kg ha −1 yr −1 reported by FAO between 1960 and 2014 (FAO, 2017). Historical time trends for soybean yield average increase have been documented in the United States (23 kg ha −1 yr −1 ; Long, 2013; Rowntree et al, 2013; Specht et al, 2014; Wilson et al, 2014), China (11 kg ha −1 yr −1 ; Wu et al, 2015), Argentina (44.33 kg ha −1 yr −1 ; de Felipe et al, 2016), and Brazil (41 kg ha −1 yr −1 ; de Toledo, 1990). Our database indicates that yield improvement was mostly associated with increased biomass and little or no change in HI, in agreement with previous studies (Schapaugh and Wilcox, 1980; Spaeth et al, 1984; Johnson and Major, 1986).…”

Evaluation by grafting technique of changes in the contribution of root-to-shoot development and biomass production in soybean (Glycine max) cultivars released from 1929 to 2006 in China

“…Our previous studies on changing trends in agronomic traits in these widely grown soybean cultivars indicated that, in North East China, newer cultivars had earlier flowering, shorter plants with fewer branches, higher lodging resistance and higher yields per plant than older cultivars, and in the YHH region, modern cultivars had shorter plants, fewer nodes, higher lodging resistance, more seeds per pod and heavier seeds than older cultivars (Wu et al 2015;Wang et al 2016). These results may shed light on strategies for soybean root improvement in different production regions.…”

“…In the past century through to 2015, more than 2400 soybean cultivars were developed in China (Wang et al 2016). During this time, yield, agronomic and phenological traits of soybean have markedly improved (Zheng et al 2006;Tian et al 2007;Zhao et al 2008Zhao et al , 2012Xu et al 2011;Wang et al 2015;Wu et al 2015;Qin et al 2017). Modern soybean varieties tend to have greater root weight, root volume, root surface and lateral root length than older varieties (Yang et al 2001).…”

How breeding of Brazilian soybean cultivars modified morphophysiological attributes of plants?

“…To determine the genetic basis of yield increase, cultivars released in different years should be sown in a common environment (Specht et al, 1999;De Bruin e Pedersen, 2008;. Such research carried out in several soybean-producing countries has shown plant-specific morphophysiological changes for each site because of yield improvement Yu et al, 2009;Jin et al, 2010;Koester et al, 2016;Wu et al, 2015). The increase of soybean yield in Brazil, carried out through breeding, was not accompanied by researches that could clarify the morphophysiological changes that occurred in the plant, and their contribution to the main objective of breeding.…”

“…Modern North American soybean cultivars partition more carbohydrates into grains(Koester et al, 2014). In this context, among the yield components that contributed most to yield increase was the number of grains per plant, both in Chinese(Jin et al, 2010;Wu et al, 2015) and in North American(De Bruin e Pedersen, 2008; cultivars.…”