Studies On Selecting And Breeding New Hybrid Of Super Sweet Corn And Variation Of Components Of Quality In Kernels In Fresh Ear Stage

It was studied on selecting and breeding sweet corn in a large-span from 1995 to 2003 in Shanghai and Guangdong province. And it was tested for determination on components of quality of kernels in fresh ear stage. Two new high stable super sweet corn parents-lines "HOI" and "H06" were obtained through improvement and creation of germplasm of inbred lines. The hybrid "(HOI × H06)" was named "ShenTian No.l" checked and accepted by Shanghai government agency. Rule of variation of kernel growth in different types of corns in fresh ear stage was also studied. The results by statistic analysis are as follows:1. A stable short parents-inbred line "HOI" with high quality and high combinationability was bred by separating foreign germplasm of sweet corn. 2 .A stable parents-inbred line "H06" with high combination ability, wideadaptation, and tolerant to hot or cold climate was created by introducinggermplasm of tropical family into that of subtropical family.3. Hybrid of super sweet corn "Shen Tian No.l "was bred with high quality, highyield, and strong resistance, whose parents-inbred lines were "HOI" and "H06".4. New mode of heterosis was built. Inbred line from foreign germplasm of supersweet corn was crossed by that from germplasm of tropical family into that of subtropical family.5.The contents of total soluble sugary (TSS) in super sweet corn was higher than that in sugary enhancer sweet corn, and than that in normal corn during kernel growth in fresh ear stage. The contents of TSS linearly increased for each type of corns in different stages.6.Moisture decreasing in normal corn was quicker than that in sugary enhancer sweet corn, and than that in super sweet corn during kernel growth in fresh ear stage. Moisture decreasing had a stable stage in super sweet corn, meanwhile it linearly decreased in each type of corns in different stages.7.Protein contents in three different types of corns linearly increased. The variation in super sweet corn was the same rules as that in sugary enhancer sweet corn, since they were sweet corns. Protein contents was a little bit higher in normal corn than that in sweet corn in each stage of kernels growth, howeverit quickly decreased when accumulation of protein was the highest (25 days after pollination).8. The weight of 100 fresh kernels linearly increased in three different types of corns to 21 days after pollination, however it was higher in super sweet corn than that in normal corn, and than that in sugary enhancer sweet corn. Dry matter in kernels accumulated in a large quantity after it was in the milk to 15 days after pollination. The rules of variation of the weight of 100 fresh kernels was that it increased sometimes and decreased sometimes for super sweet corn, while continued to increase for sugary enhancer sweet corn, and it began to decrease for normal corn when the weight of 100 fresh kernels was the heaviest (25 days after pollination).