Research On The Heterosis And Combining Ability For Main Traits Of Hybrid Rice Combinations And Genetic Of Restoring Gene And SSR Molecule Marker In K17A

To grasp combining ability and heterosis of the major characters of hybrid rice has an important pritical value on improving the breeding efficiency of priority combinations. Preliminary exploring the heredity and molecular mapping of fertility restorer gene has guiding role for better use of the male sterility line(K17A).In this paper,firstly,6 cytoplasmic types 10 male sterile lines(maintenance line) WA(Zhenshan 97A,Fuyi A, Y99A),IDA(â…¡-32A,Youâ… A,Zhong 9A),GA(Gang 46A),DA(D62A),KA(K17A), and DRA(Xieqingzao A) and 10 restorer lines R005,R132,R471,R379,R388,R389, R478,Miyang 46,Minghui 63 and En Hui 58 were used as parents to make 100 crosses by NCâ…¡design to investigate combining ability and heterosis of yield per plant,7 agronomic characters,12 quality traits,4 blast resistance index.Secondly,5 male sterile lines(maintenance line):K17A,Youâ… A,D62A,Gang 46A and Zhenshan 97A and 5 restorer lines:R617,R612,Minghui 63,R654,R655 were used as parents to make 25 crosses by NCâ…¡design to investigate combining ability and heterosis of SPAD value of the last three leaves,4 photosynthetic characteristics,5 endogenous hormone content and 9 mineral element content of hybrid rice.The light response curves of K17A/R612, Zhenshan 97A / Minghui 63 were compared with their parents.Lastly,K17A(B),Minghui 63,Kyou63(F₁) and their F₂ were used as materials to preliminary explore the heredity of fertility restorer gene and molecular mapping of K17A using SSR technique.The main results are summarized as follows:1,The main traits of 100 test combinations,the over-parent heterosis of NGP,NFP,YP,GW and the contrast heterosis of NGP,NFP,SSR,HR were strong The over-parent heterosis of CR,CH,AC and the low-parent heterosis of neck blast grade and the contrast heterosis of CR and neck blast grade were weak.The combinationâ…¡-32A/miyang 46 and Y99A/R132 were the best on yield and quality traits,the neck blast grade of K17A/R471 was the weakest on low-parent hetersis.D62A/R478,Y99A/R005 and FuyiA/Enhui 58 were the best on contrast heterosis.The over-parent heterosis and contrast heterosis of combinations with different cytoplasmic type were similar with 100 test combinations.The main traits of 25 test combinations,the over-parent heterosis of SPAD value on flag leaf and Pn,Zn at milky stage were strong.SPAD value on flag leaf,Pn,GA₁ have strong contrast heterosis,and also for K,P at active tillering stage and milky stage,Zn at active tillering stage,Fe at milky stage.Gang 46A/R654,Gang 46A/R665,K17A/R612 and Gang 46A/R665 were the best combinations on over-parent heterosis.Zhenshan 97A/R665,D62A/R612,Gang 46A/R612 and Gang 46A/R665 were the best combinations on contrast heterosis.2,All traits of 100 test combinations and the combinations with different cytoplasmic type were both controlled by GCA and SCA.The effect of SCA were bigger than GCA for seed setting rate,head rice rate of 100 test combinations and the number of panicles per plant of combinations with different cytoplasmic type.It is mainly affected by restorer lines for YP,PP and neck blast grade of 100 test combinations and CR,AC of combinations with different cytoplasmic type.The other physiological traits were affected by GCA except Pn.The effect of restorer lines were bigger than sterility lines on SPAD value,IAA,ABA,K,Zn.3,The relation between GCA and SCA was complex on test combinations.For the higher GCA parents,the high and low SCA of agronomic traits such as yield per plant were 40.40%and 41.41%respectively,low SCA of quality traits accounted for 46.15%, and high SCA of neck blast grade with a rate of 64.29%.For the lower GCA parents,the high and low SCA of agronomic traits such as yield per plant were 52.00%and 42.86% respectively,low SCA of quality traits accounted for 56.90%,and high SCA of neck blast grade with a rate of 66.23%.For the middle GCA parents,the high SCA of agronomic traits such as yield per plant and quality trait with a rate 52.00%and 42.86%respectively. For the 25 combinations with high GCA parents,high,middle and low SCA of SPAD value with the same rate of 33.33%.The middle and low SCA of Pn with the same rate of 40.00%.The high SCA of endogenous hormone content with a rate of 80.00%.The high SCA of K and Cu with a rate of 75.00%and 46.70%,respectively.The high and low SCA of P with the same rate of 37.50%.4,For NGP,NGP,GW,YP,CR,AC and neck blast grade of 100 test combinations and combinations with different cytoplasmic type,the board heritability and narrow sense heritability values were high;HR had high board heritability values and low narrow sense heritability values,but the CH degree was opposite.The physiological traits of 25 test combinations had high board heritability and narrow sense heritability values.5,For PP,NGP,NFP,GW,YP,HR,CR,CH,AC and neck blast grade,the combinations had significant or high significant positive relation with their parents.The seed setting rate had significant relation with sterility line,but had insignificant relation with restorer line.It was mainly affected by SCA and restorable ability of parents,and had little relation with the SSR of restorer line.The main difference between the 100 test combinations and cytoplasmic type combinations was the HR has no significant correlation to their parents,NFP and GW have no significant relation to restorer lines.PP, NGP,NFP,SSR,GW,YP,HR of 100 test combinations and combinations with different cytoplasmic type had significant or high significant positive correlation to over-parent heterosis.AC had significant and high significant positive correlation with average heterosis.CR and neck blast grade had significant positive correlation to low-parent heterosis.All traits have significant or high significant positive correlation to GCA of parents and SCA of combinations.For the 25 test combinations,the SPAD value of flag leaves,Pn,endogenous hormone content,K,Zn,P in active tillering stage,Fe of milky stage had significant or high significant positive relation to restorer lines.The SPAD value of flag leaf,Pn in initial stage of panicle emerging and milky stage,K and Zn in active tillering stage,Fe, Mn,P had significant or high significant positive relation to sterility lines.ABA has high significant positive relation to low-parent heterosis.Main physiological traits had significant positive relation to SCA.K,Fe,Zn and P in active tillering stage also had significant positive relation to GCA of restorer lines.The SPAD of flag leaves,Pn in initial stage of panicle emerging and milky stage,K,Fe,Mn,P,Zn had significant positive relation to GCA of sterility lines.Pn,K,Mg,Mn,P in active tillering stage,SPAD value of flag leaf in initial stage and SPAD value flag leaf on last second leaf,Pn,Tr,K,Fe,Cu, Mg,P,in milky stage,5 endogenous hormone content had significant or high significant positive relation to yield,and Ca in milky stage had high significant negative relation to yield.6,The light response curve of different combinations was not consistent.Pn,Cs and Ci of K17A/R612 were all higher than parents,Tr was in the middle of the parents.Pn and Ci of Shanyou 63 was also in the middle of the parents,Cs and Tr was lower than their parents.The light compensation point,dark respiration rate and the apparent Quantum Efficiency of K17A/R612 were lower than restorer lines and higher than sterility lines, light saturation point was lower than their parents.The light compensation point,dark respiration rate and the apparent Quantum Efficiency of Shanyou 63 were lower than their parents,and light saturation point was in the middle of both parents.The potential of yield of Shanyou was a little larger than K17A/R612.7,The fertility restorer of K17A was controlled by one pair gene,the restorer gene was located on chromosome 10,and linkage with RM6100.