Abstract: Backcross progenies BC 4F₁ of interspecific hybrid (G.hirsutum×(G.arboreum×G.bickii)) seperated crazily in every characters and many new characters appeared.According to the fertility,the plants of backcross progenies were classified into 3 groups:sterile, semisterile and fertile plant and chromosome behavior during meiosis in pollen mother cell of the interspecific hybrid F₁ and the three types were studied.The main results are as follows:the sterile cause of F₁,BC 4F₁ sterile material in the trispecific hybrid was that the chromosomes could not make a pair normally in meiosis, leading to some lagging, uneven distributing chromosomes, multispores, micronuclei and sterile pollens. In semisterile plants, the chromosomes could make a pair mostly in meiosis, only a few could not make a pair normally.In fertile plants of BC 4F₁, the chromosomes could make a pair normally in meiosis and normal pollen grains were formed, the fertility was recorved.

Key words: Interspecific hybrid, Fertility, Backcross

CLC Number: 

• S52.035.1