Natural introgression from cultivated soybean (Glycine max) into wild soybean (Glycine soja) with the implications for origin of populations of semi-wild type and for biosafety of wild species in China

Abstract

Introgression from soybean cultivars to its wild progenitor species is an interesting antidromic recombination in natural ecosystem with many consequences, including the alteration of genetic diversity, the origin of semi-wild soybean, and implication for biosafety of the wild progenitor species with future release of the genetically modified varieties. Although such interspecific introgression is not suspected to be ubiquitous in the sympatric regions of wild and cultivated soybeans, the documentations published based on some molecular experimental analyses on the introgression have been little substantiated by the occurring process morphologically and remain deficient for unquestionable evidence, owing to the lack of actual insight into the population dynamics. Here, we found the phenomenon of gene escape and presented the evidence for occurrence of introgression from soybeans into the wild species and for how originates about the semi-wild type soybean based on morphological investigation of population dynamics. Our results suggest that more attention should be paid to the escape of genetically modified genotypes to safeguard the biosafety of wild soybean gene pool, if GM soybeans are released in China, the place of origin of cultivated soybeans.

Genome Re-Sequencing of Semi-Wild Soybean Reveals a Complex Soja Population Structure and Deep Introgression

“…The latter hypothesis was supported by several studies based on the analyses of the frequency/distribution of alleles [14] and molecular markers [15] – [17] . A recent observation of inter-species gene flow, which captured the natural occurrence of introgression between cultivated and wild accessions, provided further phenotypic evidence to support the hybridization hypothesis [6] , [18] , [19] . However, the origin of this semi-wild type of soybean has not clearly been established.…”

“…The hybridization origin of the semi-wild soybean has been proposed [13] , [60] . However, direct evidence in support of this hypothesis is lacking, although hybridization events between cultivated and wild soybean have been observed in natural field conditions [6] , [18] , [19] . In this study, several genomic evidences favor the above hypothesis.…”

“…Wang et al . [18] also proposed a short creation history of semi-wild soybean based on their observation of some newly collected semi-wild lines. Additionally, the ancestry inference based on STRUCTURE result for Maliaodou indicated it is different from that of other semi-wild accessions.…”

“…It has been proven that the introgression between wild and cultivated soybean is bidirectional rather than unidirectional, i.e. from wild to cultivated soybean populations [21] , [24] , [25] , and also cultivated soybean into the wild population [18] , [19] .…”

Characterization of Soybean Hybrid Seeds Resulted from Natural Hybridization between LM Soybean and Wild Soybean

“…한 편 콩은 자화수분 작물이므로 LM콩과 야생콩 간 교잡 1 세대(F1) 개체가 생태계 내에서 살아남을 경우 자식에 의 해 계속해서 도입 유전자를 포함한 후대를 생산하게 되어 생태계에 교란을 야기시킬 수 있다 (Gepts and Papa, 2003). 현재까지 전세계적으로 LM콩 경작지에서 LM콩과 야생콩 의 교잡후대종이 자연 발생된 사례는 없으나 LM콩으로부 터 야생콩으로 유전자 이동은 6 m까지 발생 가능한 것으 로 보고되었고 (Mizuguti et al, 2010), 재배콩과 야생콩의 중간형태를 띄는 자연 교잡종(Glycine gracilis)이 중국과 일 본에서 발견되었다 (Wang et al, 2010). 이는 LM콩이 재배 되거나 비의도적으로 유출될 경우 인근에 자생하고 있는 야생콩으로의 유전자 이동 및 자연교잡 후대종 발생이 가 능하다는 것을 시사한다.…”