Genetic bases of improved soybean cultivars released from 1923 to 2005 in China—A historical review

Abstract

Improved soybean cultivars are cultivars released from a scientific breeding program in China in contrast to the historical landraces kept by farmers from their own seed lots. The pedigree data of 1300 soybean cultivars [Glycine max (L.) Merr.] released in China from 1923 to 2005 were collected, checked, and corrected. These cultivars traced back to 670 nuclear and 344 cytoplasmic ancestors; 45% (50%) of the nuclear (cytoplasmic) germplasms were from Eco-region I, 23% (26%) from II, 7% (10%) from III, 4% (5%) from IV, 1% (1%) from V, 1% (1%) from VI, 18% (7%) from foreign countries, and 0% (1%) from geographically unknown sources. Both nuclear and cytoplasmic germplasm from Eco-regions I, II, and III, and foreign countries accounted for most of the ancestry of the released cultivars. In each of the eco-regions, with the exception of region VI, but especially in region I, the local nuclear and cytoplasmic germplasm was dominant in the released cultivars. Exotic germplasm accounted for an increasing portion of the nuclear and cytoplasmic germplasm, especially in Ecoregions I and II. The genetic base of the released cultivars is relatively narrow but has been gradually broadened, especially in Eco-regions I and II; and the average number of ancestors per cultivar released between 1996 and 2005 in various eco-regions was approximately double the period between 1986 and 1995. Seventy-eight ancestors accounted for 12% of the total ancestors but explained that 64% of the nuclear contribution and 70% of the cytoplasmic contribution to the 1300 released cultivars. For broadening the genetic base of future cultivars, the utilization of germplasm from outside regions is emphasized.

Discrimination of the Geographical Origin of Soybeans Using NMR-Based Metabolomics

“…Over 1400 soybean cultivars have been developed in China between 1923 and 2013 [ 45 ] through a scientific breeding program; therefore, the parents of the cultivars were landraces, cultivars, breeding lines, and exotic introductions. During the past 20 to 40 years, the yield level of soybean cultivars has increased from 750 kg/hm 2 to 2000 kg/hm 2 in China [ 46 ].…”

A comparison of Chinese wild and cultivar soybean with European soybean collections on genetic diversity by Genome-Wide Scan

“…Currently, China has developed approximately 3000 varieties (Qiu & Wang 2007. The modern breeding process grapples with the challenge of a narrow genetic base, with most varieties developed in China between 1923 and 1995 in the main soybean-producing regions of Northeast and Huang-Huai-Hai using local varieties as parents, leading to a narrowing genetic basis due to the over-concentration of parental sources (Xiong et al 2010). Although Chinese soybeans possess a vast gene pool, traditional breeding has utilized only a fraction (Wang et al 2006).…”