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Rice is an important food crop in the world, is also subject to serious crop pest and disease threats. Rice bacterial blight and brown rice planthopper is endangering one of the most serious pest of rice production, causing huge production losses to rice production, even when serious crops. The long-term practice has proved that the use of host resistance varieties cultivate resistant to insect pests to control pests and diseases prevalent is the most economical and effective way to meet the requirements of sustainable development of modern agriculture. Rice bacterial blight is a vascular disease caused by Gram-negative bacteria Xanthomonas bacteria (Xanthomonas oryzaepv.Oryzae). In order to effectively control the outbreak and spread of bacterial blight, has been excavated screened more than 30 anti-bacterial blight major gene, but because of the narrow resistance spectrum, recessive characteristics of a variety of reasons, only a small number of genes are used to breeding practices; and have been widely used anti-blight the gene Xa3 and the resistance to Xa4 in the domestic and international rice area is now lost. Therefore, scientists from all countries are committed to digging the new resistance gene. Wild rice is long-term growth in the harsh environment, rich in adversity, pest-resistant gene, is a treasure trove of important gene screening of new anti-source. Wang Lian from excavations of wild rice, and identified a number Y238 new resistance sources, it has broad spectrum anti-resistance characteristics, by genetic analysis to prove its resistance by a dominant gene ; then through conventional crossing, backcrossing resistance genes were introduced into rice varieties King Kong 30 and IR24, near-isogenic lines CBB30, the resistance gene was named Xa30 (t). In order to carry out the resistance molecular mechanism study and breeding on the effective use of positioning and grams pliable a30 (t) gene is very important. 2006, Jin Xu Wei positioning to the Diamond 30/Y238 hybrids F2 population groups, the use of molecular markers Xa30 (t) are initially positioned on the long arm of chromosome 11. This study in IR24/Y238 Transferring the near-isogenic lines of a BC of F 2 lines mapping population Xa30 (t), the use of molecular markers to locate further to determine its position in the rice chromosome. The rice while facing disease threats, but also harm by pests, in particular Nilaparvata lugens. Nilaparvata lugens (Nilaparvam lugens St (?) L) is a monophagous pests of rice, Homoptera, Delphacidae (Homoptera Delphacidae). Wide the Nilaparvata lugens distribution area, dangers, most of the rice growing regions of the world have occurred, the occurrence in our country is very serious. Breeders and geneticists have long efforts to screen new anti-source to tap new insect-resistant genes into cultivated rice cultivating new varieties of high resistance to control pests. However, due to the difficulty of identification of resistance, conventional breeding cycle is long, leading the development of new insect-resistant varieties of the slow process. Of Nilaparvata lugens groups by biotype mainly gradually into main Biotype 2 makes the original insect-resistant varieties will lose resistance. In order to improve the efficiency of selection to speed up the breeding process, this study using molecular markers assisted selection technology, high resistance to bacterial blight the Xa23 genes and biological communities of Nilaparvata lugens genes showed high resistance Bph18 (t) polymerization, imported into quality breeding of high quality anti-rice restorer line of hybrid rice in 9311 and measured 253 intermediate materials. In this study, the following main results: 1, nurturing a IR24/Y238 turn fertile offspring BC 6 F 2 groups, with the identification of Xoo P6 inoculation, groups in seedling stage and adult plant resistance to flu than are in line with the ratio of 3:1. The resistance of this group by a dominant gene, therefore, be identified as Xa30 (t) gene mapping population. Utilize distributed on the 12 rice chromosomes SSR, EST, STS and specific PCR marker, through the separation of Group Analysis (BSA) in F 2 groups between the resistant and susceptible pools were screened to over 6 the normality the mark 03STS Lj74/Y02W1R, A83b4, Lj 112 Lj 121 and RM206. F 2 groups monoclonal molecular detection and comprehensive analysis of Xa30 (t) is positioned between markers 03 STS and Lj 112 and with marked A83b4 total separation, completely cover the rice sequencing varieties Nipponbare BAC clone AC104847, AC137588, BAC clone AC136148 and AC137589 partially covered, about 412kb. 2, according to Bph18 (t) were isolated molecular markers 7314.T4A amplified fragment sequence information, molecular bioinformatics technology developed three genes closely Bph18 (t) the PCR marker KC5 chain KC1F/7312.T4AR, and 7312.T4AF/KC2R. Hybrid rice restorer line carrying Xa23 gene 9311, and measured 253 as the recurrent parent carrying Bph18 (t) gene the indica material 4064 non-recurrent parent hybridization and backcrossing the use KC5, KC1F/7312.T4AR and tightly linked to markers STS2F/3R the 7312.T4AF/KC2R mark and Xa23 gene molecular detection of disease and insect resistance genes, combined with the identification of each alternative P6 bacteria, now imported into the recurrent parent Bph18 (t) and Xa23 gene, get to 9311 BC genetic background 3 F 1 materials and to the measured 253 genetic background BC 3 F 1 materials.
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