Screening And Application Of New Restorer Lines Of Three Line Hybrid Rice Resistant To Rice Blast

Rice is one of the three major food crops in the world.More than half of the world’s population takes rice as the staple food.The safety production of rice is related to the sustainable development of my country’s agriculture and national security issues.Rice blast is a widespread fungal disease endangering rice growth,which has a significant impact on Rice Yield and quality.At present,the most economical and effective measure to control rice blast is to use long-lasting broad-spectrum resistance genes to select long-lasting resistant varieties.The resistance,yield and quality of restorer lines are the key factors for breeding excellent hybrid rice.Therefore,breeding excellent disease resistant restorer lines is the basis for breeding good rice varieties.This study uses the excellent recovery of Huazhan as the parental parent,and hybridizes with Changhui83 the parental parent of the anti-rice plague gene.Combined with the identification of natural induction nursery of rice blast in the field,the resistant plants and lines were selected.After multiple generations of continuous selfing selection in the South and North,a number of excellent restorer lines with strong resistance were successfully selected.Among them,the New Restorer Line Changhui 83(19CR18)showed strong resistance to rice blast,good yield and good rice quality.Through observation and multi-point comparison test,a new combination with strong dominant disease resistance,Quan 9 you 83,was finally selected.The main results are as follows:1.A number of excellent new restorer lines were preliminarily selected:This study is based on hybrid breeding technology and combines modern breeding technologies.In 2019,a number of new recovery materials with strong resistance,high yield,and excellent rice quality 19CR04,19CR10,19CR18,19CR21,and 19CR29 were selected.The 19CR18(Changhui 83)showed outstanding performance.2.The main characteristics of Changhui 83:Changfu 83 was planted in Jingzhou,with an average output of 6.52 t/hm2,which is4.27%compared with Huang Huazhan’s increase in yield.And the whole growth period was 127 days,7 days later than the control.The plant height is 109.8cm,the type is moderate,the division,stems and growth is strong,and the color is good in the later period.The ear length is 24.0cm,the number of grains per ear is 167.8,the seed setting rate is85.6%,the thousand seed weight is 27.66g,the brown rice rate is 77.8%,the whole milled rice rate is 64.5%,the chalky grain rate is 3.3%,and the chalkiness degree is 1.2%.Resistant to rice blast and moderately susceptible to sheath blight.Changhui 83 has strong restoring ability.After test crossing with several male sterile lines,the seed setting rate of the combination is more than 84%;The general combining ability of ear traits such as seed setting rate,thousands of grain weight and yield per plant was high.The special combining ability of each character among combinations was in the middle and upper level among 20 combinations.After preliminary test and retest,the Quan 9 you 83 showed strong heterosis with lush plants,good leaf type,high and stable yield.The stage sowing experiment showed that the initial sowing period of Changhui 83 was stable,which was86±3 days;the effective accumulated temperature is stable,about 1250℃;The number of main stem leaves is about 17.3.The configuration application of Changhui 83:The Changhui 83 showed good general combining ability and special combining ability with multiple male sterile lines.The Quan 9 you 83 shows that the yield is about3000 kg per hectare,the stem is strong,the powder is not easy to break,the heading is concentrated,there are many spikelets at the flowering stage,the amount of pollen is large,the flowering time is concentrated,and the seed production is easy to obtain high yield.Quan 9 you 83 was planted as one season medium rice in Jingzhou in 2021.The whole growth period was 124 days,which was 3 days later than the control Fengliangyou4.The stem is strong,resistant to fertilizer and lodging,has strong tillers,straight leaves,general color conversion,colorless sheath floating color,long grain and no awn.The plant height is 116.4cm,the ear length is 26.1cm,the number of grains per ear is 178.7,the seed setting rate is 83.5%,the thousand seed weight is 28.8g,and the yield is 8.88t/hm2,Compared with the control,the yield increased by 7.3%.The rate of brown rice is 76.4%,the rate of whole milled rice is 63.6%,the rate of chalky grain is 11.3%,and the chalkiness is 2.7%.The comprehensive resistance index of rice blast was 1.6,the highest loss rate of ear blast was 1,and the resistance to rice blast was 1,resistance to rice blast;susceptible to rice false smut and susceptible to sheath blight in Jingzhou.The yield of Quan 9 you83 at several test sites in Wuling mountain area was significantly different from that of the control,and the comprehensive yield ranked first,which was significantly higher than that of Ruiyou 399.The average yield of the combination was 9.19t/hm~2 in 9 test sites,Compared with the control Ruiyou 399,the yield was significantly increased by 8.67%.Compared with its parent huazhan,the New Restorer Line Changhui 83 screened in this study has increased tillers,better plant leaf type,more tenacious stems,moderate plant height,high combining ability and strong resistance to rice blast.It has certainmarket application value.Changhui 83 can’t only form excellent combinations with many male sterile lines because of its excellent recoverability and general combining ability,but also can be used as an intermediate material in subsequent breeding goals by virtue of its excellent agronomic characters.In the process of material selection,this study focused on the analysis of combining ability and heritability,which provided a reference basis for understanding the characteristics of combining ability and heritability of self bred materials,and was conducive to the later material creation;Then the sowing date experiment was carried out to explore the characteristics of the restorer line,and the breeding points were determined according to the reproductive characteristics of the matched combination Quan 9 you 83;The multi-point observation test provided a good data support for the regional test of variety follow-up application.