Abstract:In order to explore the function of the rape miR1140, we cloned the premiR1140 gene from rape cultivated variety westar by PCR approach, and successfully constructed the plant expression vector of premiR1140 with vector pPZP212, and transformed into variety westar by agrobacterium tumefaciens mediated approach. (1) PCR identification indicated that 14 strains positive transgenic plants of BnamiR1140 gene over expressed have been obtained; (2) Phenotypic observation showed that leaf morphology and flower tube of positive strains do not mutate, plant height, length of main inflorescence, the number of principal inflorescences and the 1 000grain weight are all equivalent to the control. But there are 5 positive strains with BnamiR1140 transformed (T0) expressed double main sequence phenotype, and the branch height lower than control, branching number increased significantly than control, make the whole effective pod number increase, single productivity increased by 26% than that of control, and other 9 strains positive strains were consistent with that of wild type rape phenotype. (3) T1 field phenotype analysis showed that the total growth period of T1 transmutation plant of 5 strains with 35S∷BnamiR1140 (T0 generation) overexpressed was significantly increased by 9-14 d compared with the control group, and, of which there are four strains, their plant type variation genetic followed 3∶1 Mendel segregation law. The study speculated that BnamiR1140 may participate in the regulation of branching and development of oilseed rape.