**4.5 Identification of mutants**

From the G1 generation to G3 generation of grafted scion, there are different types of mutants to take on. The mutated traits include the morphological and physiological traits. Before these mutants are used for genetic research and breeding materials, they had better

The robust soybean seedlings are selected as scions. The roots are first rinsed with tap water, and then dried out with the filter paper. After that, the stem of soybean seedling is shaved down to the wedged end from the top root hairs with the wallpaper blade, and the wedge

After pulling out the bamboo stick from the hole of rootstock, the prepared scion is immediately inserted into the hole of rootstock slowly with moderate force, assuring that

After the scion is inserted into the hole of the rootstock, the joint site and scion are

In order to enhance the survival rate of graft, the graft union must be shaded for about 45 days. The strength of shaded light gradually goes down, and finally drops close to natural

During the shading period, the rootstock is not only supplied with enough water for normal growth, but also the scion plant is offered necessary water one time per day using the micro-

7 days after grafting, the lateral roots may grow from the scion. It is necessary to check the newly-grown lateral roots of scion daily, and promptly remove them with a surgical blade. These works will continue to 45 days after grafting so that the scion can host on the

At 45 days after grafting, the part above the surface soil 10cm of the main stem of the

After removing the main stem of rootstock, the graft union is transferred to normal growth conditions until the scion plant can mature regularly and the seeds (G0 generation) are

From the G1 generation to G3 generation of grafted scion, there are different types of mutants to take on. The mutated traits include the morphological and physiological traits. Before these mutants are used for genetic research and breeding materials, they had better

immediately embedded and fixed using the clay with a humidity of 60-70%.

**4.3.2 Whittling the stem of scion into wedge end** 

**4.3.3 Inserting the scion into the rootstock** 

the scion end just reaches the bottom of the hole.

**4.3.4 Embedding the joint site with the clay** 

length is generally 1.0-1.5 cm.

**4.4 Management measures 4.4.1 Shading the graft union** 

**4.4.2 Supplying water for the scion** 

**4.4.3 Removing the lateral roots from the scion** 

**4.4.4 Removing the main stem of rootstock** 

condition.

sprayer.

rootstocks.

gained.

rootstock is cut down.

**4.4.5 Later management** 

**4.5 Identification of mutants** 

be subject to molecular identification through different molecular maker methods. The detailed methods for identification of soybean mutants refer to the methods of Li *et al*. (2003).
