Detection Of QTLs For Traits Of Heading Date In Rice And Breeding Insect-resistant And Rice Blast Disease-resistant Rice Varieties By Backcrossing

Heading date (HD) is an important agronomy trait in rice, locationing the QTL controlingheading date and studying the genetic effect is importance in rice breeding. In this paper,detection of the QTLs controlling heading date in rice was done with40SSSLs by usingHuajingxian74as recipient parent, using QTL substitution mapping analysis,11QTLs wereidentified. On the other hand, the QTL fine mapping of heading date on chromosome8alsobe involved in this research based on markers, which lay a foundation for the followingresearch of gene localization and molecular marker-assisted breeding work. The main resultswere as follows:1、In2012and2013,30SSSLs for heading date were detected in40SSSLs, and78.9%ofthe SSSLs were detected repeat in two years.11QTLs were identified with QTL substitutionmapping analysis, and location in chromosomes1,2,3,4,6,8and10was labeled. ThoseQTLs usually had larger additive effects and were less affected by the environment.2、From the library, SSSL W02-15-7-3with a substituted interval of RM447--RM264-RM281--Long Arm was found to have gene for extremely late heading date which performedstable and late heading. The gene on the chromosome8for heading date was tentativelydesignated as qHD8-1.An F2segregating population from a cross between SSSLW02-15-7-3and Huajingxian74was developed. In the segregating population, the segregation ratio of lateand early heading plants was in accordance with3:1, indicating late heading was controlledby a major dominant gene. The locus was delimited to a86.5kb interval between markersRM23588and RM3496.Rice is one of the major food crops in the world. With the growth of the population and theloss of arable land, the world will face food problem of severe challenges. To cultivate highquality of insect-resistant and rice blast disease-resistant rice became an important way toimprove grain production. In this paper, transgenic insect-resistant Indica rice TT51withcry1Ab/1Ac from Minghui63and hua1517B with Pi1/Pi2were transferred into the mainacceptor parents Shengdao14cultivated in Huanghuai area by successive backcrossing. Themain results were as follows: 1、Three highly insect-resistant lines from TT51with cry1Ab/1Ac, Two highly rice blastdisease-resistant lines from hua1517B with Pi1/Pi2, PCR identification and field insect-resistance selection.2、The statistic analysis and evaluation on insect-resistance rice showed these line hadresistant to insect pests and good plant phenotype. This study will play an important role inbreeding of the transgenic rice.