| Title: | QTL affecting fitness of hybrids between wild and cultivated soybeans in experimental fields |
| Authors: | Kuroda, Y., Kaga, A., Norihiko, T., Yano, H., Takada, Y., Kato, S., Vaughan, D. |
| Source: | Ecol. Evol. 2013, 3(7):2150-2168 |
| Abstract: | The objective of this study was to identify quantitative trait loci (QTL) affecting fitness of hybrids between wild soybean (Glycine soja) and cultivated soybean (Glycine max). Seed dormancy and seed number, both of which are important for fitness, were evaluated by testing artificial hybrids ofÊG. sojaÊ_ÊG. maxÊin a multiple-site field trial. Generally, the fitness of the F1Êhybrids and hybrid derivatives from self-pollination was lower than that ofÊG. sojaÊdue to loss of seed dormancy, whereas the fitness of hybrid derivatives with higher proportions ofÊG. sojaÊgenetic background was comparable with that ofÊG. soja. These differences were genetically dissected into QTL for each population. Three QTLs for seed dormancy and one QTL for total seed number were detected in the F2Êprogenies of two diverse cross combinations. At those four QTLs, theÊG. maxÊalleles reduced seed number and severely reduced seed survival during the winter, suggesting that major genes acquired during soybean adaptation to cultivation have a selective disadvantage in natural habitats. In progenies with a higher proportion ofÊG. sojaÊgenetic background, the genetic effects of theÊG. maxÊalleles were not expressed as phenotypes because theÊG. sojaÊalleles were dominant over theÊG. maxÊalleles. Considering the highly inbreeding nature of these species, most hybrid derivatives would disappear quickly in early self-pollinating generations in natural habitats because of the low fitness of plants carryingÊG. maxÊalleles. |