Screening And Application Of Two-line New Restorer Lines Of Hybrid Rice Resistant To Rice Blast

The safety of rice production is closely related to the life of the Chinese people;Among the common diseases and pests of rice,rice blast is the most harmful fungal disease,which will occur widely in all rice planting areas all over the world.Through the breeding technology of two-line hybrid rice,the main goal of this study was to cultivate two-line hybrid rice combinations with strong resistance to rice blast.A new restorer line,Changhui 117,was created by hybridizing with an excellent Indica Restorer Line(donor parent)with the current or once popularized indica rice material r982-8 as the receptor in production.Through extensive combination with the dominant two-line male sterile line materials,a new hybrid rice combination with strong dominant resistance to rice blast,mingliangyou 117,was obtained.Breeding strong heterosis hybrid combinations resistant to rice blast and vigorously promoting their application will effectively reduce the cost of applying pesticides and chemical fertilizers,reduce the harm to the environment,maintain the crop growth environment,maintain soil fertility and increase farmers’ production profits.The main results of this study are as follows:1.Creation of New Restorer line materials and screening of new resistance sourcesChanghui 31,a high-quality restorer line material with resistance to rice blast,was selected as the donor parent and hybridized with R982-8,an excellent material currently popularized in production,as the recipient parent.After years of self crossing,test crossing and pedigree breeding in the South and North,through natural induction identification in the disease nursery,New Restorer line materials with high combining ability,strong resistance to rice blast and excellent rice quality were screened,and 3restorer lines with better comprehensive performance were created,That is,8HR02,8HR34 and 8HR41,of which 8HR02 is derived from R982-8/Changhui31.The comprehensive disease resistance grade of this plant is grade 1,showing resistance to rice blast.The ear forming rate was 82.89%,the total number of grains was 236.8,the seed setting rate was 92.73%,the 1000 grain weight was 28.63 g,the brown rice rate was 77.39%,the head rice rate was 71.8%,the chalkiness rate was 6.252%,and the chalkiness degree was 5%.The comprehensive performance was the most outstanding,so it was named Changhui 117.After the identification and screening of rice blast resistance of the planted materials in Enshi rice blast area,a total of 18 restorer materials with good resistance to rice blast were obtained.Among them,the varieties with obvious resistance to rice blast were YZ01,YZ02,YZ03,YZ06,YZ10,YZ11,YZ16,and 7 varieties with comprehensive disease grade of 0 or 1,showing resistance to rice blast.The above-mentioned materials can not only create new hybrid combinations with excellent two-line male sterile lines,but also be used as new blast resistant materials,which provides a direction for subsequent breeding.2.Heterosis identification and combining ability determination of hybrid combinationsIn this study,the combining ability and Heterosis of the hybrid combinations were identified by incomplete diallel cross.The results showed that Changhui 117 showed high general combining ability,especially in yield,growth period,seed setting rate and plant height.But the general combining ability of 1000 grain weight was more general than that of other varieties.The general combining ability of effective panicle,total grain number and panicle length was worse than that of other materials.At the same time,Changhui 117 and many male sterile lines showed high special combining ability,among which mings/ Changhui 117 showed the best special combining ability.It was found that the average yield of combination mings/ Changhui 117 was8.72t/hm2,which was 9.14% higher than that of the control Jinyou 207.The yield increase was very significant,ranking the first.The growth period is 130 days,the effective ear is 2.898 million ears /hm2,the ear length is 25.1cm,the plant height is125.14 cm,the seed setting rate is 85.14%,and the 1000 grain weight is 27.17 g.The resistance grade of rice blast was grade 1,showing resistance to rice blast.Brown rice rate is 80.49%,head rice rate is 70.78,chalky grain rate is 3.6%,chalkiness degree is1.6%.With excellent comprehensive performance,it was named mingliangyou 117.After trial production in Hainan,it participated in multi-point product comparison test.3.Characteristics and combination trial production of Mings / Changhui 117 parentsThe main characteristics of Changhui 117 are: it belongs to the late maturing type of medium indica rice.In Jingzhou area,the starting calendar period of summer sowing is about 88 days,and the main stem leaves are about 16 leaves.The main characteristics of Ming s: Ming s was sown in Jingzhou for about 77 days in spring and about 70 days in summer.The number of leaves on the main stem is 13-15.The trial production results of the new combination showed that the seed production yield of Mings / Changhui 117(8HR02)combination was high.In Sanya,Hainan,the male parent sowed in late December and the female parent sowed in early January.The arrangement of parents’ sowing difference should be dominated by time difference,supplemented by leaf difference.The time difference is 11 days,and the leaf difference is 1.6 leaves.Parents’ heading date should be arranged in late March.The yield of the trial varieties in the current season reached more than 2250 kg per hectare,indicating that the male parent had a large amount of pollen and concentrated flower time,so it was easy to obtain high yield in seed production.4.Performance of new combination participating in multi-point product comparison testThe results of multi-point product comparison test showed that Mings / Changhui117 was outstanding in all the tested combinations.The product comparison test was carried out in 7 different ecological areas,and the yield of this combination was higher than that of the control;The highest panicle loss rate of rice blast in this combination is1.1,which belongs to rice blast resistant varieties.The highest level of sheath blight is5,and the highest level of Rice False Smut is 1.The resistance performance was better than that of the control;At the same time,the overall rice quality of the combination was better than that of the control.The new combination showed good high and stable yield,resistance to rice blast,suitable ripening period and excellent appearance rice quality in the product comparison test.It can be promoted to participate in the provincial or national regional test.