Differential Analysis Of QTLs For Chlorophyll Contents In Four Grain-filling Stages In Rice

A double haploid(DH) population consisting of 120 lines derived from the cross between a japonica parent Chunjiang 06 and an indica parent TN1 was used to detect QTLs controlling chlorophyll contents in four grain-filling stages in rice with a new constructed genetic map of 226 SSR. Seven chlorophyll-content QTLs were detected and distributed on chromosomes 4, 6 and 8. Expression of QTLs for chlorophyll contents in different stages varied. The QTLs from the third leaf mainly expressed in the early stages of grain-filling, and the QTLs from the second and flag leaves did in the later stages. In the first and second measuring stages, four chlorophyll-content QTLs were detected, only three and two detected in third and fourth stages, respectively. Total contribution rates in four grain-filling stages reduced gradually, indicating chlorophyll contents in early stages of grain-filling were higher, which is just close relative to leave aging. Qchl2,andQchl4-1,Qchl4-2,Qchl8-1 and Qchl8-2 made effects on chlorophyll contents in early and middle stages of grain-filling, Qchl6-1 and Qchl6-2 were detected from flag leaf in third and fourth stages, respectively, indicating that the two QTL were perhaps close relative to the"keeping green"character of flag leaf or leave aging.Additionally, 36 pairs of interaction were detected for chlorophyll contents. Only five of them located on the same chromosome, others did on different chromosomes. Six pairs co-acted between the main-effect QTLs and non main-effect one. No pair happened between the main-effect QTLs. These loci such as the QTL(RM520) on chr. 3, the RM 575 on chr.1 and the RM85 on chr. 8 etc were checked simultaneously in two or more leaves/measuring times.Conditonal analysis showed that nine development behavior of chlorophyll contents were detected, and located on the chromosomes 2,5,6,8 and 11. Two allelic genes on the chromosome 5 and one on the chromosome 11 were from the parent TN1,and other six were from CJ06. Their total contribution rate was 26.7%. The gene(RM587) on the chromosome 6 expressed stably owing to its high expresson from the t2-t1 measurin times. So the RM587 could be detected both in the t3 and t4. The net expression increased for the RM310 locus on the chr 8, so the Qchl8 could be identified in two/more measuaring times.The RM1111 locus for chlorophyll contents could be detected in various perioud, and its effect is significant and was useful gene. Some lines including DH12,DH46å’ŒDH79 were backcrossed with the TN1 due to its allelic gene was from CJ06. then using the RM1111 and to construct NIL-Qchl8. Now the BC₂ F₂ population construction have been finished.