| As one of major grain crops in the world,maize occupied an important position in economics and agriculture.In the background of environmental problem and marketing competition,traditional breeding methods have no longer satisfied the need of social development today,so it is imperative to breed new varieties with high and stable qualities of maize by genetic engineering.Carotenoids are a group of natural pigments,which have diversified structures and functions.In higher plants,carotenoids participate in light-harvesting processes,and protect photosynthetic components from photooxidation.Carotenoids also act as precursors of abscisic acid and vitamin A.In human and animals,carotenoids serving as important antioxidants and dietary complements of provitamin A,are essential nutritions.Gene Isopentenyl pyrophosphate isomerase?IPI?and Bar were transferred into Hoo-108,which is the female parent of maize Tianta 5,by the transformation of mature embryo in situ.T1 transformants were screened with phosphinotricin of 500mg·L-1 and 750 mg·L-1,and 18 lines of T1 positive plants were confirmed by PCR test.53 lines of T2 positive plants were confirmed by screened with phosphinotricin of 750mg·L-11 and PCR test.5 lines of T2 positive plants were selected for subsequent examination,129 of T3 positive plants were confirmed by screened with phosphinotricin of 750 mg·L-11 and PCR test,and the ratio of positive plants were all above 60%.The photosynthetic rate of T3 transgenic plants was significantly higher than the control.The analysis of HPLC showed that the total carotenoids contents in transgenic maize were improved significantly,especially the?-carotene content which increased by 59.35%,compared with the control.With regard to compare the agronomic traits in phenophase,growth period and panicle traits,there was no significant difference with the control.But transgenic maize had better performance of lodging resistance and hundred grains weight between the control and transgenic maize. |
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