APPLICATION OF GREY-SYSTEM THEORY IN RAPE BREEDING
Wu Zhenggang (Agricultural Institute of south-eastern Qian prefecture kai-li Guizhou)
Grey-system theory relationship method has been used to caculate mean values of seven principle agronomic characters including yield per plant for seven good F2 families from the combination of 81008 ×(Tall + H4). Correlation between yield per plant and other agronomic, characters have also been analysed. Results show that: number of effective branches per plant make the largest contribution to yield (r3 = 0.9766), And then plant hight (r1 = 0.7733), number of grains per pod (r5 = 0.6689), number of effective pods per plant (r4 = 0.4930), weight of 1000 grains (r6 = 0.3956)and length of top inflorescence (r2 = 0.3504) in order. Therefore, number of effective branches are the first agronomic character considered for selection in F3 and F4 generations of the combination. The 1000-graih weight, length of effective section of top inflorescence are not considered as main characters for selection ri's dispersion proves that grey measage may be changed into white by using grey-system relationship method.