Studies On The Corn Germplasm Enhancement By The Techology Of EMS Inducing Mature Pollens

The studies make use of EMS (ethyl methane sulfonate ) to induce the maize materials' mature pollen of the differently genetic background to transform its growth period (photoperiod),the herbicide resistance and the else resistance. In the induced offspring the lines including of the target mutation are selected through three generations "observing, choosing and judging. And the selected inbred lines are selfed as the new resources in order to enhance the germplasm.The results of the study indicate that it is feasible to transform the maize growth period by way of EMS-paraffin inducing the mature pollen. For the temperate zone materials, the growth period can be transformed from one day to eight days; for the influence of growth period the total trend is the put-off. As for the resistance, the two inbred lines out of the six temperate inbred lines has changed. Especially for the resistance to the com worm EMS has a obvious effect. For example the original inbred line of K12 is sensitive to the corn worm; though the two times insecticide are used, but the leafages become yellow, the tassel is damaged greatly, so as to the value in use of the high combining ability inbred line is at a discount. In the induced offspring there are five ear rows of the high resistance to the corn worm. As for the tropic materials EMS-paraffin does not have the influence obviously; for the photoperiod (growth period), it has the obvious effect. In the three tropic populations of the study there are three ear-rows of early-maturity mutation. It make clear that only the variation of grain color 'ear is a real mutation; its plant type and its tassel look like the ETO's ones. But its plant tallness is about 175 cm and the ETO plant tallness is about 350 cm. And the study also indicates that the low concentration EMS(<10?) makes for the early maturity and that the high concentration ( > 10"3 ) makes for the late maturity . For the resistance to herbicide, at the present time there is not the high resistance tothe herbicide of Roundup owing to the low population. The highest resistant concentration is up to the two times of the deadly dose. This dose can not satisfy what is required in use for the field. But the result indicates that the effect that the induced objects are the complicated genetic background is more obvious than the one that the induced objects are the inbred line. Which has the instructive meaning for the continuous study.