【作者】 邓化冰；

【导师】 陈立云； 邓启云；

【作者基本信息】 湖南农业大学 ， 作物遗传育种， 2005， 博士

【摘要】 本研究以具有两个主效增产QTL(yld1.1和yld2.1)的马来西亚普通野生稻(Oryza rufipogon)为供体,9311、明恢63和Ce64为受体和轮回亲本,采用连续回交并结合分子标记辅助选择方法将这两个野生稻增产QTL转移至杂交水稻父本中,育成携带野生稻增产QTL的新恢复系,并通过对其杂种优势水平及主要农艺性状的比较,对野生稻增产QTL(yld1.1和yld2.1)的增产效果和原理等进行了研究和探讨,获得如下结果: [1] 分析了与野生稻增产QTL紧密连锁的6个SSR标记亲本间的多态性,运用其中的4个多态性标记进行标记辅助选择,并对其PCR反应体系和程序进行了优化。运用的4个标记中有3个标记与目标位点的遗传距离均小于5cM,即RM166与yld2.1的遗传距离,RM9、RM5与yld1.1的遗传距离均小于5cM,因此分子标记辅助选择结果有效。 [2] 对野生稻增产QTL的传递规律的研究表明,野生稻增产QTL在各回交世代中能稳定遗传,各回交后代群体中具野生稻RM166特异标记个体比例均低于其理论值(50%)。对相同回交世代中回交群体与回交自交群体中具野生稻特异标记个体的比例比较分析,发现回交自交群体中具野生稻特异标记个体的比例明显高于回交群体。 [3] 建立了分别以9311及明恢63为受体且携带野生稻增产QTL的回交近交系,为野生稻增产QTL的精细定位和功能研究奠定了基础。通过对以明恢63和9311为受体构建的野生稻增产QTL的回交近交系与受体间产量性状的比较分析,表明携带野生稻增产QTL回交近交系的理论产量和实测产量均高于受体亲本,将野生稻增产QTL转移至杂交水稻恢复系或父本中,能提高其产量水平;且野生稻两个增产QTL的增产效果大于单个野生稻增产QTL-yld2.1或QTL-yld1.1。 [4] 将野生稻增产QTL转入9311中,育成携带野生稻增产QTL的9311改良系24个,与培矮64S、P88S所配系列组合平均理论产量和实测产量均高于对照组合两优培九;90%以上组合的理论产量和实测产量均高于对照。说明,野生稻增产QTL在杂更多还原

【Abstract】 In this study, a wild accession of Oryza rufipogon ( ’ O. rufipogon’ ) from Malasia which contained two major yield-enhancing QTLs (yId1.1 and yld2.1) on chromosomes 1 and 2 respectively, were chosen as the donor of yield-enhancing QTLs. The hybrid rice restoration lines (9311 and Minghui63 and Ce64) were used as the recipient and recurrent parents. Some new hybrid rice restoration lines which contained the two yield-enhancing QTLs (yldl. 1 and yld2.1) were developed by marker assisted selection (MAS). The yield-enhancing effect and the mechanism revolved of the two yield-enhancing QTLs (yldl. 1 and yld2.1) were studied by means of comparing hybrid vigor and main agronomic characters between new restoration lines and its original parents. The major results were as follows:1. Polymorphism of Six SSR markers (RM9、 RM24、 RM5、 RM306、 RM208、 RM166) which were mapped to the genomic region linked to the two yield-enhancing alleles (yldl.l and yld2.1) between donor and recipient parents was analyzed , four of which, i.e., RM9, RM5, RM166 and RM208, were used for MAS in this study. In fact, RM9 and RM5 were flanked to yld1. 1 on chromosome 1, with genetic distance of 2.5cM and 0cM, respectively. And RM166 and RM208 were linked to yld2.1 on chromosome 2 at the genetic distance of 3.1cM and 6.5cM, respectively. In this study, SSR analysis of RM166, RM208 ,RM9 and RM5 were performed. The results indicated that these molecular markers are feasible for MAS to screen rice individuals withthe yield-enhancing QTLs.2. The results showed that the two yield-enhancing alleles (yldl.l and yld2.1) could be inherited steadily in the backcrossed populations. The percentage of the individuals that contain marker RM166 in backcrossed progenies of BC2Fh BC3Fi( BC4F1, BC5F1 and BCeFj was lower than 50%. The percentage of the individuals that contained marker RM166 or RM9 in progenies from selfing of backcrossed population was higher than that of the progeny of backcrossed population.3. Backcross inbred lines (BIL) of the two yield-enhancing QTLs (yldl.l and yld2.1) with recipient parents of 9311 and MH63 were developed respectively, which is essential for further studies of the two yield-enhancing QTLs (yldl. 1 and yld2.1). Compared with its original parent, BILs of the two yield-enhancing QTLs with recipient parents of 9311 and MH63 had higher yield. The results indicated that the two yield-enhancing QTL could be transferred into the restoration line of hybrid rice, and which could increase rice yield. The yield-increasing effect with both yield-enhancing QTL alleles yldl.l and yld2.1 was higher than that of the single yield-enhancing QTL allele yld2.1 or yldl. 1. -4. 24 improved 9311 lines which contained the two yield-enhancing QTLs (yldl. 1 and yld2.1) were developed by transferring the two yield-enhancing QTLs (yldl.l and yld2.1) into 9311 (a top-performing paternal line in super hybrid rice seed production in China). The average yield potential and the average harvest yield of the hybrids of 24 improved 9311 lines crossing with Peiai64S and P88S ( two TGMS) were higher than that of Liangyoupeiyiu (CK), respectively. Among 48 hybrids derived from 24 improved 9311 lines,46 ones had higher theoretical yield , 40 had higher harvest yield on comparison with the CK, the percentage of yield-increased hybrid combinations was 95.8% and 83.3% respectively. The results indicated that the two yield-enhancing QTLs iyldl. 1 and yld2.1) were expressed well in genetic background of 9311 lines and its hybrids.5. The genetic background analysis of the backcrossed progeny BC4F4 and BC6F2 with recipient parent of 9311 were conducted by SSR. The difference of the genetic background between the progeny BC4F4 and its original parent 9311 reached to the level of 12.2%. The main agronomic characters of the progeny of BC6F2 was similar to its original parent 9311.6. The results showed that 24 improved 9311 lines and its hybrids had more effective panicles , higher seed-setting rate and 1000-grain weight than that of 9311 and the control hybrid respectively. More effective panicles were the main reason for yield-increasing of improved 9311 lines and its hybrids.7. Compared with the hybrids of Ce64, hybrids of Q611 which contained two yield-enhancing QTLs (yldl.l and yld2.1) increased both the average sink capacity per unit area and the average total spikelets number per unit area by 6.30% and 14.46% respectively. Among 21 hybrids of Q611, 18 hybrids had larger sink capacity and more total spikelets number than that of the hybrids of Ce64. The results showed that Q611 had a good general combining ability, and the hybrid vigor of the hybrids from Q611 was higher than that of the hybrids of Ce64. The results indicated that the two yield-enhancing QTLs iyldl. 1 and yld2A) were expressed fully in the new restorer line Q611 and its hybrids.8. Some elite hybrid combinations which contained the two yield-enhancing QTLs (yldl.l and yld2.1) were developed through the methodology of MAScombined with the method of general breeding. The percentage of yield-increased of elite hybrid combination PH023 and PHI09 reached to the level of 16.0%.9. A package of breeding technologies based on MAS for yield-enhancing QTLs (yldl.l and yld2.1) has been developed.更多还原