1.Introduction To meet the food demand of the Chinese people in the 21st century,a super-rice breeding program aimed at increasing rice yield was initiated by the Ministry of Agriculture of China in 1996.It is divided...1.Introduction To meet the food demand of the Chinese people in the 21st century,a super-rice breeding program aimed at increasing rice yield was initiated by the Ministry of Agriculture of China in 1996.It is divided into four phases,with the following yield targets:10.5 t ha^(-1)(phase I,1996–2000),12 t ha^(-1)(phase II,2001–2005),13.5 t ha^(-1)(phase III,2006–2015),and 15 t ha^(-1)(phase IV,2016–2020)~[1].The average yield of super-rice should be verified in two locations of 6.7 ha each in two consecutive years.展开更多
Heterosis for yield and its component traits between chromosome segments from IR24, an indica variety, and the counterparts from 02428, a japonica rice, was inves- tigated by using a hybrid F1 population composed of 6...Heterosis for yield and its component traits between chromosome segments from IR24, an indica variety, and the counterparts from 02428, a japonica rice, was inves- tigated by using a hybrid F1 population composed of 63 com- binations between 02428 and IR24 chromosome segment substitution lines (CSSLs) with the genetic background of Asominori, a japonica variety. Significant differences in het- erosis for yield and yield-component traits were observed among the crosses. Analysis of graphical genotyping showed that 14 substituted segments were responsible for yield het- erosis. All of them were from all the 12 chromosomes of IR24 except chromosomes 8 and 10. Six segments at the intervals of RFLP markers, such as X132—G1340—R459, X48— C393A, R288—R1854, R2918—X52, X257—C1350 and R367 —X189-2—X24-2 on chromosomes 2, 3, 4, 11 and 12 respec- tively, had very significant heterosis for yield at the level of P ≤0.005 based on t-test, individually increasing the hybrid yield by more than 35% compared with the control cross “Asominori×02428”. Most of IR24 chromosome segments were found to have no significant hybrid effect for yield and yield-component traits, and one segment located at R2171 on chromosome 6 possessed significant negative effect with 27% of yield decrease. Advantages of using CSSLs in the heterosis studies were discussed and approaches of the partial and genome-wide exploitation of rice heterosis between indica and japonica by molecular marker-assisted selection were then proposed.展开更多
文摘1.Introduction To meet the food demand of the Chinese people in the 21st century,a super-rice breeding program aimed at increasing rice yield was initiated by the Ministry of Agriculture of China in 1996.It is divided into four phases,with the following yield targets:10.5 t ha^(-1)(phase I,1996–2000),12 t ha^(-1)(phase II,2001–2005),13.5 t ha^(-1)(phase III,2006–2015),and 15 t ha^(-1)(phase IV,2016–2020)~[1].The average yield of super-rice should be verified in two locations of 6.7 ha each in two consecutive years.
基金This work was supported by the High Technology Research and Development Pro-gram of China(Grant Nos.2002AA207020 and 2001AA241024)the National Natural Science Foundation of China(Grant No.30370906).
文摘Heterosis for yield and its component traits between chromosome segments from IR24, an indica variety, and the counterparts from 02428, a japonica rice, was inves- tigated by using a hybrid F1 population composed of 63 com- binations between 02428 and IR24 chromosome segment substitution lines (CSSLs) with the genetic background of Asominori, a japonica variety. Significant differences in het- erosis for yield and yield-component traits were observed among the crosses. Analysis of graphical genotyping showed that 14 substituted segments were responsible for yield het- erosis. All of them were from all the 12 chromosomes of IR24 except chromosomes 8 and 10. Six segments at the intervals of RFLP markers, such as X132—G1340—R459, X48— C393A, R288—R1854, R2918—X52, X257—C1350 and R367 —X189-2—X24-2 on chromosomes 2, 3, 4, 11 and 12 respec- tively, had very significant heterosis for yield at the level of P ≤0.005 based on t-test, individually increasing the hybrid yield by more than 35% compared with the control cross “Asominori×02428”. Most of IR24 chromosome segments were found to have no significant hybrid effect for yield and yield-component traits, and one segment located at R2171 on chromosome 6 possessed significant negative effect with 27% of yield decrease. Advantages of using CSSLs in the heterosis studies were discussed and approaches of the partial and genome-wide exploitation of rice heterosis between indica and japonica by molecular marker-assisted selection were then proposed.
