| The rice restorer line is one of the important parents for heterosis utilization. A fine restorer line is the foundation of obtaining good hybrid rice combination. People focus mostly on the yield of rice owing to the large population of our country. The planting area of rice will be decreased as the strengthening of the policy of returning farmland to forest and grassland, so high yield is particular important. The rice quality is getting increased attention with the raise of people’s living standard. The blast, bacterial blight and brown planthopper are the three major diseases and insect pests affecting rice yield in China. Breeding resistant varieties is an effective way to prevent these diseases and insect pests. This research improved the restorer lines using the polymerization line of high-yield, good quality and disease- resistant and single segment substitution line(SSSL) of insect-resistant. The main results are as follows:(1) The 3 restorer lines named G3-2R, P132-06 and P132-46 were respectively improved by using 3 polymerization lines containing high-yield and good quality QTLs, a polymerization line containing disease-resistance QTLs and a SSSL containing insect-resistant QTL. In late season of 2015, 16 homozygous lines and 4 homozygous plants were screened in 9 high-yield and good quality combinations, and 15 homozygous lines and 4 homozygous plants were screened in 6 disease and insect resistant combinations. The target of pyramiding breeding of restorer lines was completed.(2) The restorability and yield and quality correlated traits of the 16 new obtained restorer lines which were pyramided with high-yield and good quality QTLs were investigated. The pollen fertility ranged in 82.81%-95.55% and the spikelet fertility ranged in 84.79%-94.05%. The effective panicle number per plant, panicle length, total grains number per panicle, filled grain number per panicle, seed setting rate, thousand grain weight and yield per plant were investigated in late season of 2015. 12 improved restorer lines were higher than HJX74(W0) in yield per plant and 4 were significant difference; 4 improved restorer lines were lower than W0 in yield per plant. The grain length of restorer lines which contained gs3 gene were longer then W0 and significant difference. The grain length of restorer lines which contained gs3 gene were longer than W0 and extremely significant difference. The heading data of restorer lines which contained the gene Hd-1-2 were earlier than before and later than W0.(3) The restorability of the 15 new obtained restorer lines which were pyramided with disease or insect-resistant QTLs were investigated; and 2 contained the gene XA21 were investigated bacterial blight resistance. The pollen fertility ranged in 84.35%-95.74% and the spikelet fertility ranged in 86.67%-92.48%. The 2 restorer lines were vaccinated the bacterial blight bacteria in late season of 2015. The bacterial blight resistance was enhanced to a certain degree. 4 improved restorer lines were higher than W0 in yield per plant; 11 improved restorer lines were lower than W0 in yield per plant and 1 was significant difference.The study utilized restorer lines, polymerization lines of high-yield and good quality or disease-resistant and SSSL of insect-resistant which were bred by our lab to conduct pyramiding breeding by MAS. The new restorer lines had a certain extent improvement in yield and quality or disease and insect resistance. It prepared for material to rice breeding and later improving. |
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