Nutritive value comparison among straw from different generations of hybrid offspring

In the present study, we compared the nutrition values of straw from different generations of hybrid offspring of wild soybean (Glycine soja) and cultivated soybean (G.max), which may provide scientific basis for the forage soybean cross breeding technology. The results show that the contents of crude protein, crude ash and calcium in the reciprocal cross offspring of wild soybean and cultivated soybean are higher than those in the direct cross offspring, while the contents of crude fiber and crude fat in the reciprocal cross offspring are lower than those of direct cross offspring. From generation F1 to F4 of the hybrid offsprings through both direct and reciprocal crossing, the contents of the crude protein and crude ash in the plants increased, and the values increased from 5.66% and 4.74% to 16.34% and 6.59%, respectively. However, the contents of crude fiber, neutral detergent fiber and acid detergent fiber decreased, and the values decreased from 41.78%, 69.31% and 50.83% to 35.36%, 60.10% and 42.07%, respectively. Comprehensive comparison shows that the nutritive value of the RCF41 is the best in hybrid offspring, therefore it may be excellent forage potentially, and it could be used for breeding the forage soybean material.