When the horizontal level falls down the slope-break,a full horizontal level fluctuating cycle is formed,a system including lowstand tract,lake expand and lake shrink(trisection tracts).
) male_sterile line 1066A as female parent and Yugu 1 primary trisomic series (1-7) and tetrasomics 8, 9 as male parents, chromosome location of gene for male_sterility and yellow seedling in line 1066A was studied by primary trisomic analysis.