Transformation And Inheritance Of The Herbicide Basta Resistant Gene To Upland Rice By Hybridization

At present, genetic transformation technology point out the direction for the development of traditional plant breeding.On genetic rules and expression modes of transgenic gene in crops, more previous researches focuses on transgenic plant itself and its inbred progenies. Only a few of studies involved the hybrid progenies between transgenic plant and traditional varieties. Exploring genetic rules of herbicide Basta resistant gene and developing herbicide resistant upland rice by hybridizing between transgenic lowland rice lines and upland rice varieties will be much more beneficial to herbicide resistant gene utilization and accelerate upland rice dissemination.To analyze the genetic rules of different transgenic lines and select lines with herbicide resistance, drought resistance and other ideal agronomic traits, two transgenic lowland rice lines ,Jingyin 119 and Jiahe 99,which contain herbicide Basta resistance gene called bar, were used to cross with upland rice varieties.Reciprocal crossing and back crossing have proved that the bar gene is a dominant single nuclear gene and it doesn't influenced by the cytoplasm, which is consistant with previous studies. Spraying 0.05% (PPT) "Basta" and investigating the ratio of resistant and sensitive plants, it indicated that the separate ratios of the progenies with paternal line ZY-3 accord with the "Mendel laws", i.e the ratio of backcross is 1:1, and that of F2 generation is 3:1. While those of the progenies with paternal line ZY-2 don't accord with the "Mendel laws", which are about 5:1, near to the separate ratio of the F2 generation of the paternal line, i. e 5.8:1. The results showed that the hybrid progenies inherit the paternal genetic mode possibly, different transgenic lines have different genetic transformation mode and that genetic mode doesn't change when use it as parent lines.PCR analysis and Southern-blotting test both prove that the expect gene has been integrated into the upland rice and inherited stably into the F1, F2, F3and F4 progenies of the transgenic rice. But there are much difference on the herbicide resistance level among different varieties, which means that the expression level of the bar gene is different for different genotypes.For all crosses in this study, the crosses of upland rice 502 or 65 with ZY-3(Jiahe 99) obtained ideal lines, while there is no ideal line among the crosses with ZY-2 (Jingyin 119) as paternal line.Comparing with ZY-3,ZY-2 caused bigger variation among F4 lines .The traits of the F4 lines from parent ZY-3 were different obviously than contrast parents. It indicated that the effect on progeny variation is different between ZY-2 and ZY-3. It shows that ZY-3 is a better idea parent for resistant Basta gene transfer to upland rice through crossing in upland field.The study proves that the genetic rule of bar gene is sequential between the transgenic parent and their progenies. Combining screen of herbicide Basta resistant and selection of the drought resistance level among the progenies which have vast variation, it is a feasible method to obtain both of herbicide resistance and drought tolerant lines even varieties with better agronomic traits than its upland rice parents.