GENE TRANSFORMATION BY PARTICLE BOM-BARDMENT IN INDICA RICE AND INHERITANCE OF THE FOREIGN GENE IN HOST RICE PLANT

Embryogenic calli induced from mature seeds and cell suspensions were used as explants for particle bombardment.Plasmid p ILTAB2 2 7containing hph gene and gus gene under the control of Ca MV35 S was introduced into different varieties of Indica rice.Resistant plants of Indica rice varieties Basmati1,Qingyouzhan,Xinshanzhan2 9,Shengyou2,Minghui63were obtained.Tissue histochemical staining analysis of gus gene and Southern blot analysis of DNA isolated from leaves of T₀ plants displayed the presence of gus and hph genes in the rice genome.We chose Basmati1as a model and evaluated the expression of hph gene in T₁,T₂ and T₃generations in order to provide us to study further the expression,regulation and control of other important agronomically genes in rice.The segregation ratio of3:1(positive:negative for transgene) was found common in the T₁progeny,itindicated that inheritance of transgene was in accordance with Mendelian rule of dominant gene with one locus.In addition, the selfed progeny of some independent plants show the segregation ratio of 1:1.Itwas assumed that the aberrant ratio of1:1resulted from gene suppression of female gamete or male gamete.Mendelian fashion of hph gene was further confirmed and homozygotes for hph gene were identified in the T₂ and T₃lines.Meanwhile,the suppression and activation of foreign gene in the progeny of transgenic plants was put forward to discussion.